diff --git a/.python-version b/.python-version
index 7bcbb3808b5..c49282585a0 100644
--- a/.python-version
+++ b/.python-version
@@ -1 +1 @@
-3.4.9
+3.5.6
diff --git a/configure.ac b/configure.ac
index da922b3cc0e..5335a6a4465 100644
--- a/configure.ac
+++ b/configure.ac
@@ -725,6 +725,10 @@ if test x$TARGET_OS != xwindows; then
   AX_CHECK_COMPILE_FLAG([-fPIC],[PIC_FLAGS="-fPIC"])
 fi
 
+# All versions of gcc that we commonly use for building are subject to bug
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90348. To work around that, set
+# -fstack-reuse=none for all gcc builds. (Only gcc understands this flag)
+AX_CHECK_COMPILE_FLAG([-fstack-reuse=none],[HARDENED_CXXFLAGS="$HARDENED_CXXFLAGS -fstack-reuse=none"])
 if test x$use_hardening != xno; then
   use_hardening=yes
   AX_CHECK_COMPILE_FLAG([-Wstack-protector],[HARDENED_CXXFLAGS="$HARDENED_CXXFLAGS -Wstack-protector"])
diff --git a/doc/dependencies.md b/doc/dependencies.md
index 229f9ca7422..1b3df62867a 100644
--- a/doc/dependencies.md
+++ b/doc/dependencies.md
@@ -22,7 +22,7 @@ These are the dependencies currently used by Bitcoin Core. You can find instruct
 | OpenSSL | [1.0.1k](https://www.openssl.org/source) |  | Yes |  |  |
 | PCRE |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L66) |
 | protobuf | [2.6.1](https://github.com/google/protobuf/releases) |  | No |  |  |
-| Python (tests) |  | [3.4](https://www.python.org/downloads) |  |  |  |
+| Python (tests) |  | [3.5](https://www.python.org/downloads) |  |  |  |
 | qrencode | [3.4.4](https://fukuchi.org/works/qrencode) |  | No |  |  |
 | Qt | [5.9.7](https://download.qt.io/official_releases/qt/) | [5.5.1](https://github.com/bitcoin/bitcoin/issues/13478) | No |  |  |
 | XCB |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk#L87) (Linux only) |
diff --git a/doc/man/Makefile.am b/doc/man/Makefile.am
index 9b36319e649..edbc0911a16 100644
--- a/doc/man/Makefile.am
+++ b/doc/man/Makefile.am
@@ -15,3 +15,9 @@ endif
 if BUILD_BITCOIN_TX
   dist_man1_MANS+=bitcoin-tx.1
 endif
+
+if ENABLE_WALLET
+if BUILD_BITCOIN_WALLET
+  dist_man1_MANS+=bitcoin-wallet.1
+endif
+endif
diff --git a/doc/reduce-traffic.md b/doc/reduce-traffic.md
index dd1469f5638..5a71f62e0f8 100644
--- a/doc/reduce-traffic.md
+++ b/doc/reduce-traffic.md
@@ -35,3 +35,16 @@ blocks and transactions to fewer nodes.
 Reducing the maximum connected nodes to a minimum could be desirable if traffic
 limits are tiny. Keep in mind that bitcoin's trustless model works best if you are
 connected to a handful of nodes.
+
+## 4. Turn off transaction relay (`-blocksonly`)
+
+Forwarding transactions to peers increases the P2P traffic. To only sync blocks
+with other peers, you can disable transaction relay.
+
+Be reminded of the effects of this setting.
+
+- Fee estimation will no longer work.
+- Not relaying other's transactions could hurt your privacy if used while a
+  wallet is loaded or if you use the node to broadcast transactions.
+- It makes block propagation slower because compact block relay can only be
+  used when transaction relay is enabled.
diff --git a/src/Makefile.test.include b/src/Makefile.test.include
index 84bc326cfe5..0408686c176 100644
--- a/src/Makefile.test.include
+++ b/src/Makefile.test.include
@@ -78,6 +78,7 @@ BITCOIN_TESTS =\
   test/bswap_tests.cpp \
   test/checkqueue_tests.cpp \
   test/coins_tests.cpp \
+  test/compilerbug_tests.cpp \
   test/compress_tests.cpp \
   test/crypto_tests.cpp \
   test/cuckoocache_tests.cpp \
diff --git a/src/bench/bench_bitcoin.cpp b/src/bench/bench_bitcoin.cpp
index d67b2c5bc78..f46c5070453 100644
--- a/src/bench/bench_bitcoin.cpp
+++ b/src/bench/bench_bitcoin.cpp
@@ -49,7 +49,7 @@ int main(int argc, char** argv)
     SetupBenchArgs();
     std::string error;
     if (!gArgs.ParseParameters(argc, argv, error)) {
-        fprintf(stderr, "Error parsing command line arguments: %s\n", error.c_str());
+        tfm::format(std::cerr, "Error parsing command line arguments: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
 
@@ -73,7 +73,7 @@ int main(int argc, char** argv)
 
     double scaling_factor;
     if (!ParseDouble(scaling_str, &scaling_factor)) {
-        fprintf(stderr, "Error parsing scaling factor as double: %s\n", scaling_str.c_str());
+        tfm::format(std::cerr, "Error parsing scaling factor as double: %s\n", scaling_str.c_str());
         return EXIT_FAILURE;
     }
 
diff --git a/src/bitcoin-cli.cpp b/src/bitcoin-cli.cpp
index b0e1f67d939..76cc19cc881 100644
--- a/src/bitcoin-cli.cpp
+++ b/src/bitcoin-cli.cpp
@@ -101,7 +101,7 @@ static int AppInitRPC(int argc, char* argv[])
     SetupCliArgs();
     std::string error;
     if (!gArgs.ParseParameters(argc, argv, error)) {
-        fprintf(stderr, "Error parsing command line arguments: %s\n", error.c_str());
+        tfm::format(std::cerr, "Error parsing command line arguments: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
     if (argc < 2 || HelpRequested(gArgs) || gArgs.IsArgSet("-version")) {
@@ -115,26 +115,26 @@ static int AppInitRPC(int argc, char* argv[])
             strUsage += "\n" + gArgs.GetHelpMessage();
         }
 
-        fprintf(stdout, "%s", strUsage.c_str());
+        tfm::format(std::cout, "%s", strUsage.c_str());
         if (argc < 2) {
-            fprintf(stderr, "Error: too few parameters\n");
+            tfm::format(std::cerr, "Error: too few parameters\n");
             return EXIT_FAILURE;
         }
         return EXIT_SUCCESS;
     }
     if (!fs::is_directory(GetDataDir(false))) {
-        fprintf(stderr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", "").c_str());
+        tfm::format(std::cerr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", "").c_str());
         return EXIT_FAILURE;
     }
     if (!gArgs.ReadConfigFiles(error, true)) {
-        fprintf(stderr, "Error reading configuration file: %s\n", error.c_str());
+        tfm::format(std::cerr, "Error reading configuration file: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
     // Check for -testnet or -regtest parameter (BaseParams() calls are only valid after this clause)
     try {
         SelectBaseParams(gArgs.GetChainName());
     } catch (const std::exception& e) {
-        fprintf(stderr, "Error: %s\n", e.what());
+        tfm::format(std::cerr, "Error: %s\n", e.what());
         return EXIT_FAILURE;
     }
     return CONTINUE_EXECUTION;
@@ -499,7 +499,7 @@ static int CommandLineRPC(int argc, char *argv[])
     }
 
     if (strPrint != "") {
-        fprintf((nRet == 0 ? stdout : stderr), "%s\n", strPrint.c_str());
+        tfm::format(nRet == 0 ? std::cout : std::cerr, "%s\n", strPrint.c_str());
     }
     return nRet;
 }
@@ -512,7 +512,7 @@ int main(int argc, char* argv[])
 #endif
     SetupEnvironment();
     if (!SetupNetworking()) {
-        fprintf(stderr, "Error: Initializing networking failed\n");
+        tfm::format(std::cerr, "Error: Initializing networking failed\n");
         return EXIT_FAILURE;
     }
     event_set_log_callback(&libevent_log_cb);
diff --git a/src/bitcoin-tx.cpp b/src/bitcoin-tx.cpp
index 4be89aab6cf..dcf6dddf291 100644
--- a/src/bitcoin-tx.cpp
+++ b/src/bitcoin-tx.cpp
@@ -81,7 +81,7 @@ static int AppInitRawTx(int argc, char* argv[])
     SetupBitcoinTxArgs();
     std::string error;
     if (!gArgs.ParseParameters(argc, argv, error)) {
-        fprintf(stderr, "Error parsing command line arguments: %s\n", error.c_str());
+        tfm::format(std::cerr, "Error parsing command line arguments: %s\n", error.c_str());
         return EXIT_FAILURE;
     }
 
@@ -89,7 +89,7 @@ static int AppInitRawTx(int argc, char* argv[])
     try {
         SelectParams(gArgs.GetChainName());
     } catch (const std::exception& e) {
-        fprintf(stderr, "Error: %s\n", e.what());
+        tfm::format(std::cerr, "Error: %s\n", e.what());
         return EXIT_FAILURE;
     }
 
@@ -103,10 +103,10 @@ static int AppInitRawTx(int argc, char* argv[])
             "\n";
         strUsage += gArgs.GetHelpMessage();
 
-        fprintf(stdout, "%s", strUsage.c_str());
+        tfm::format(std::cout, "%s", strUsage.c_str());
 
         if (argc < 2) {
-            fprintf(stderr, "Error: too few parameters\n");
+            tfm::format(std::cerr, "Error: too few parameters\n");
             return EXIT_FAILURE;
         }
         return EXIT_SUCCESS;
@@ -722,21 +722,21 @@ static void OutputTxJSON(const CTransaction& tx)
     TxToUniv(tx, uint256(), entry);
 
     std::string jsonOutput = entry.write(4);
-    fprintf(stdout, "%s\n", jsonOutput.c_str());
+    tfm::format(std::cout, "%s\n", jsonOutput.c_str());
 }
 
 static void OutputTxHash(const CTransaction& tx)
 {
     std::string strHexHash = tx.GetHash().GetHex(); // the hex-encoded transaction hash (aka the transaction id)
 
-    fprintf(stdout, "%s\n", strHexHash.c_str());
+    tfm::format(std::cout, "%s\n", strHexHash.c_str());
 }
 
 static void OutputTxHex(const CTransaction& tx)
 {
     std::string strHex = EncodeHexTx(tx);
 
-    fprintf(stdout, "%s\n", strHex.c_str());
+    tfm::format(std::cout, "%s\n", strHex.c_str());
 }
 
 static void OutputTx(const CTransaction& tx)
@@ -827,7 +827,7 @@ static int CommandLineRawTx(int argc, char* argv[])
     }
 
     if (strPrint != "") {
-        fprintf((nRet == 0 ? stdout : stderr), "%s\n", strPrint.c_str());
+        tfm::format(nRet == 0 ? std::cout : std::cerr, "%s\n", strPrint.c_str());
     }
     return nRet;
 }
diff --git a/src/bitcoin-wallet.cpp b/src/bitcoin-wallet.cpp
index 32a539aac66..ea311e7cc52 100644
--- a/src/bitcoin-wallet.cpp
+++ b/src/bitcoin-wallet.cpp
@@ -37,7 +37,7 @@ static bool WalletAppInit(int argc, char* argv[])
     SetupWalletToolArgs();
     std::string error_message;
     if (!gArgs.ParseParameters(argc, argv, error_message)) {
-        fprintf(stderr, "Error parsing command line arguments: %s\n", error_message.c_str());
+        tfm::format(std::cerr, "Error parsing command line arguments: %s\n", error_message.c_str());
         return false;
     }
     if (argc < 2 || HelpRequested(gArgs)) {
@@ -49,7 +49,7 @@ static bool WalletAppInit(int argc, char* argv[])
                                      "  bitcoin-wallet [options] <command>\n\n" +
                                      gArgs.GetHelpMessage();
 
-        fprintf(stdout, "%s", usage.c_str());
+        tfm::format(std::cout, "%s", usage.c_str());
         return false;
     }
 
@@ -57,7 +57,7 @@ static bool WalletAppInit(int argc, char* argv[])
     LogInstance().m_print_to_console = gArgs.GetBoolArg("-printtoconsole", gArgs.GetBoolArg("-debug", false));
 
     if (!fs::is_directory(GetDataDir(false))) {
-        fprintf(stderr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", "").c_str());
+        tfm::format(std::cerr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", "").c_str());
         return false;
     }
     // Check for -testnet or -regtest parameter (Params() calls are only valid after this clause)
@@ -88,7 +88,7 @@ int main(int argc, char* argv[])
     for(int i = 1; i < argc; ++i) {
         if (!IsSwitchChar(argv[i][0])) {
             if (!method.empty()) {
-                fprintf(stderr, "Error: two methods provided (%s and %s). Only one method should be provided.\n", method.c_str(), argv[i]);
+                tfm::format(std::cerr, "Error: two methods provided (%s and %s). Only one method should be provided.\n", method.c_str(), argv[i]);
                 return EXIT_FAILURE;
             }
             method = argv[i];
@@ -96,13 +96,13 @@ int main(int argc, char* argv[])
     }
 
     if (method.empty()) {
-        fprintf(stderr, "No method provided. Run `bitcoin-wallet -help` for valid methods.\n");
+        tfm::format(std::cerr, "No method provided. Run `bitcoin-wallet -help` for valid methods.\n");
         return EXIT_FAILURE;
     }
 
     // A name must be provided when creating a file
     if (method == "create" && !gArgs.IsArgSet("-wallet")) {
-        fprintf(stderr, "Wallet name must be provided when creating a new wallet.\n");
+        tfm::format(std::cerr, "Wallet name must be provided when creating a new wallet.\n");
         return EXIT_FAILURE;
     }
 
diff --git a/src/bitcoind.cpp b/src/bitcoind.cpp
index dde75c1b129..22120f9cf29 100644
--- a/src/bitcoind.cpp
+++ b/src/bitcoind.cpp
@@ -71,7 +71,7 @@ static bool AppInit(int argc, char* argv[])
     SetupServerArgs();
     std::string error;
     if (!gArgs.ParseParameters(argc, argv, error)) {
-        fprintf(stderr, "Error parsing command line arguments: %s\n", error.c_str());
+        tfm::format(std::cerr, "Error parsing command line arguments: %s\n", error.c_str());
         return false;
     }
 
@@ -89,7 +89,7 @@ static bool AppInit(int argc, char* argv[])
             strUsage += "\n" + gArgs.GetHelpMessage();
         }
 
-        fprintf(stdout, "%s", strUsage.c_str());
+        tfm::format(std::cout, "%s", strUsage.c_str());
         return true;
     }
 
@@ -97,25 +97,25 @@ static bool AppInit(int argc, char* argv[])
     {
         if (!fs::is_directory(GetDataDir(false)))
         {
-            fprintf(stderr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", "").c_str());
+            tfm::format(std::cerr, "Error: Specified data directory \"%s\" does not exist.\n", gArgs.GetArg("-datadir", "").c_str());
             return false;
         }
         if (!gArgs.ReadConfigFiles(error, true)) {
-            fprintf(stderr, "Error reading configuration file: %s\n", error.c_str());
+            tfm::format(std::cerr, "Error reading configuration file: %s\n", error.c_str());
             return false;
         }
         // Check for -testnet or -regtest parameter (Params() calls are only valid after this clause)
         try {
             SelectParams(gArgs.GetChainName());
         } catch (const std::exception& e) {
-            fprintf(stderr, "Error: %s\n", e.what());
+            tfm::format(std::cerr, "Error: %s\n", e.what());
             return false;
         }
 
         // Error out when loose non-argument tokens are encountered on command line
         for (int i = 1; i < argc; i++) {
             if (!IsSwitchChar(argv[i][0])) {
-                fprintf(stderr, "Error: Command line contains unexpected token '%s', see bitcoind -h for a list of options.\n", argv[i]);
+                tfm::format(std::cerr, "Error: Command line contains unexpected token '%s', see bitcoind -h for a list of options.\n", argv[i]);
                 return false;
             }
         }
@@ -147,18 +147,18 @@ static bool AppInit(int argc, char* argv[])
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
 #endif
-            fprintf(stdout, "Bitcoin server starting\n");
+            tfm::format(std::cout, "Bitcoin server starting\n");
 
             // Daemonize
             if (daemon(1, 0)) { // don't chdir (1), do close FDs (0)
-                fprintf(stderr, "Error: daemon() failed: %s\n", strerror(errno));
+                tfm::format(std::cerr, "Error: daemon() failed: %s\n", strerror(errno));
                 return false;
             }
 #if defined(MAC_OSX)
 #pragma GCC diagnostic pop
 #endif
 #else
-            fprintf(stderr, "Error: -daemon is not supported on this operating system\n");
+            tfm::format(std::cerr, "Error: -daemon is not supported on this operating system\n");
             return false;
 #endif // HAVE_DECL_DAEMON
         }
diff --git a/src/init.cpp b/src/init.cpp
index d0933766a52..557102efc4c 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -106,14 +106,13 @@ static fs::path GetPidFile()
 
 NODISCARD static bool CreatePidFile()
 {
-    FILE* file = fsbridge::fopen(GetPidFile(), "w");
+    fsbridge::ofstream file{GetPidFile()};
     if (file) {
 #ifdef WIN32
-        fprintf(file, "%d\n", GetCurrentProcessId());
+        tfm::format(file, "%d\n", GetCurrentProcessId());
 #else
-        fprintf(file, "%d\n", getpid());
+        tfm::format(file, "%d\n", getpid());
 #endif
-        fclose(file);
         return true;
     } else {
         return InitError(strprintf(_("Unable to create the PID file '%s': %s"), GetPidFile().string(), std::strerror(errno)));
@@ -376,7 +375,7 @@ void SetupServerArgs()
     gArgs.AddArg("-blocksdir=<dir>", "Specify blocks directory (default: <datadir>/blocks)", false, OptionsCategory::OPTIONS);
     gArgs.AddArg("-blocknotify=<cmd>", "Execute command when the best block changes (%s in cmd is replaced by block hash)", false, OptionsCategory::OPTIONS);
     gArgs.AddArg("-blockreconstructionextratxn=<n>", strprintf("Extra transactions to keep in memory for compact block reconstructions (default: %u)", DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN), false, OptionsCategory::OPTIONS);
-    gArgs.AddArg("-blocksonly", strprintf("Whether to operate in a blocks only mode (default: %u)", DEFAULT_BLOCKSONLY), true, OptionsCategory::OPTIONS);
+    gArgs.AddArg("-blocksonly", strprintf("Whether to reject transactions from network peers. Transactions from the wallet or RPC are not affected. (default: %u)", DEFAULT_BLOCKSONLY), false, OptionsCategory::OPTIONS);
     gArgs.AddArg("-conf=<file>", strprintf("Specify configuration file. Relative paths will be prefixed by datadir location. (default: %s)", BITCOIN_CONF_FILENAME), false, OptionsCategory::OPTIONS);
     gArgs.AddArg("-datadir=<dir>", "Specify data directory", false, OptionsCategory::OPTIONS);
     gArgs.AddArg("-dbbatchsize", strprintf("Maximum database write batch size in bytes (default: %u)", nDefaultDbBatchSize), true, OptionsCategory::OPTIONS);
@@ -446,7 +445,7 @@ void SetupServerArgs()
 #endif
     gArgs.AddArg("-whitebind=<addr>", "Bind to given address and whitelist peers connecting to it. Use [host]:port notation for IPv6", false, OptionsCategory::CONNECTION);
     gArgs.AddArg("-whitelist=<IP address or network>", "Whitelist peers connecting from the given IP address (e.g. 1.2.3.4) or CIDR notated network (e.g. 1.2.3.0/24). Can be specified multiple times."
-        " Whitelisted peers cannot be DoS banned and their transactions are always relayed, even if they are already in the mempool, useful e.g. for a gateway", false, OptionsCategory::CONNECTION);
+        " Whitelisted peers cannot be DoS banned", false, OptionsCategory::CONNECTION);
 
     g_wallet_init_interface.AddWalletOptions();
 
@@ -518,7 +517,7 @@ void SetupServerArgs()
     gArgs.AddArg("-mempoolreplacement", strprintf("Enable transaction replacement in the memory pool (default: %u)", DEFAULT_ENABLE_REPLACEMENT), false, OptionsCategory::NODE_RELAY);
     gArgs.AddArg("-minrelaytxfee=<amt>", strprintf("Fees (in %s/kB) smaller than this are considered zero fee for relaying, mining and transaction creation (default: %s)",
         CURRENCY_UNIT, FormatMoney(DEFAULT_MIN_RELAY_TX_FEE)), false, OptionsCategory::NODE_RELAY);
-    gArgs.AddArg("-whitelistforcerelay", strprintf("Force relay of transactions from whitelisted peers even if they violate local relay policy (default: %d)", DEFAULT_WHITELISTFORCERELAY), false, OptionsCategory::NODE_RELAY);
+    gArgs.AddArg("-whitelistforcerelay", strprintf("Force relay of transactions from whitelisted peers even if the transactions were already in the mempool or violate local relay policy (default: %d)", DEFAULT_WHITELISTFORCERELAY), false, OptionsCategory::NODE_RELAY);
     gArgs.AddArg("-whitelistrelay", strprintf("Accept relayed transactions received from whitelisted peers even when not relaying transactions (default: %d)", DEFAULT_WHITELISTRELAY), false, OptionsCategory::NODE_RELAY);
 
 
@@ -1411,7 +1410,7 @@ bool AppInitMain(InitInterfaces& interfaces)
     // see Step 2: parameter interactions for more information about these
     fListen = gArgs.GetBoolArg("-listen", DEFAULT_LISTEN);
     fDiscover = gArgs.GetBoolArg("-discover", true);
-    fRelayTxes = !gArgs.GetBoolArg("-blocksonly", DEFAULT_BLOCKSONLY);
+    g_relay_txes = !gArgs.GetBoolArg("-blocksonly", DEFAULT_BLOCKSONLY);
 
     for (const std::string& strAddr : gArgs.GetArgs("-externalip")) {
         CService addrLocal;
diff --git a/src/net.cpp b/src/net.cpp
index 67c6a5c7985..a3bca8d1131 100644
--- a/src/net.cpp
+++ b/src/net.cpp
@@ -79,7 +79,7 @@ static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL; // S
 //
 bool fDiscover = true;
 bool fListen = true;
-bool fRelayTxes = true;
+bool g_relay_txes = !DEFAULT_BLOCKSONLY;
 CCriticalSection cs_mapLocalHost;
 std::map<CNetAddr, LocalServiceInfo> mapLocalHost GUARDED_BY(cs_mapLocalHost);
 static bool vfLimited[NET_MAX] GUARDED_BY(cs_mapLocalHost) = {};
diff --git a/src/net.h b/src/net.h
index db44ec63339..6cae35e8e09 100644
--- a/src/net.h
+++ b/src/net.h
@@ -523,7 +523,7 @@ CAddress GetLocalAddress(const CNetAddr *paddrPeer, ServiceFlags nLocalServices)
 
 extern bool fDiscover;
 extern bool fListen;
-extern bool fRelayTxes;
+extern bool g_relay_txes;
 
 extern limitedmap<uint256, int64_t> mapAlreadyAskedFor;
 
diff --git a/src/net_processing.cpp b/src/net_processing.cpp
index d524d626c39..ab30104c472 100644
--- a/src/net_processing.cpp
+++ b/src/net_processing.cpp
@@ -336,7 +336,7 @@ static void PushNodeVersion(CNode *pnode, CConnman* connman, int64_t nTime)
     CAddress addrMe = CAddress(CService(), nLocalNodeServices);
 
     connman->PushMessage(pnode, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::VERSION, PROTOCOL_VERSION, (uint64_t)nLocalNodeServices, nTime, addrYou, addrMe,
-            nonce, strSubVersion, nNodeStartingHeight, ::fRelayTxes));
+            nonce, strSubVersion, nNodeStartingHeight, ::g_relay_txes));
 
     if (fLogIPs) {
         LogPrint(BCLog::NET, "send version message: version %d, blocks=%d, us=%s, them=%s, peer=%d\n", PROTOCOL_VERSION, nNodeStartingHeight, addrMe.ToString(), addrYou.ToString(), nodeid);
@@ -2011,7 +2011,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
             return false;
         }
 
-        bool fBlocksOnly = !fRelayTxes;
+        bool fBlocksOnly = !g_relay_txes;
 
         // Allow whitelisted peers to send data other than blocks in blocks only mode if whitelistrelay is true
         if (pfrom->fWhitelisted && gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))
@@ -2266,7 +2266,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr
     if (strCommand == NetMsgType::TX) {
         // Stop processing the transaction early if
         // We are in blocks only mode and peer is either not whitelisted or whitelistrelay is off
-        if (!fRelayTxes && (!pfrom->fWhitelisted || !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)))
+        if (!g_relay_txes && (!pfrom->fWhitelisted || !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY)))
         {
             LogPrint(BCLog::NET, "transaction sent in violation of protocol peer=%d\n", pfrom->GetId());
             return true;
@@ -3096,23 +3096,22 @@ bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& inter
         if (m_enable_bip61) {
             connman->PushMessage(pfrom, CNetMsgMaker(INIT_PROTO_VERSION).Make(NetMsgType::REJECT, strCommand, REJECT_MALFORMED, std::string("error parsing message")));
         }
-        if (strstr(e.what(), "end of data"))
-        {
+        if (strstr(e.what(), "end of data")) {
             // Allow exceptions from under-length message on vRecv
             LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught, normally caused by a message being shorter than its stated length\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
-        }
-        else if (strstr(e.what(), "size too large"))
-        {
+        } else if (strstr(e.what(), "size too large")) {
             // Allow exceptions from over-long size
             LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
-        }
-        else if (strstr(e.what(), "non-canonical ReadCompactSize()"))
-        {
+        } else if (strstr(e.what(), "non-canonical ReadCompactSize()")) {
             // Allow exceptions from non-canonical encoding
             LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
-        }
-        else
-        {
+        } else if (strstr(e.what(), "Superfluous witness record")) {
+            // Allow exceptions from illegal witness encoding
+            LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
+        } else if (strstr(e.what(), "Unknown transaction optional data")) {
+            // Allow exceptions from unknown witness encoding
+            LogPrint(BCLog::NET, "%s(%s, %u bytes): Exception '%s' caught\n", __func__, SanitizeString(strCommand), nMessageSize, e.what());
+        } else {
             PrintExceptionContinue(&e, "ProcessMessages()");
         }
     }
diff --git a/src/noui.cpp b/src/noui.cpp
index c7d8fee0ba7..0c18b0e231c 100644
--- a/src/noui.cpp
+++ b/src/noui.cpp
@@ -37,7 +37,7 @@ bool noui_ThreadSafeMessageBox(const std::string& message, const std::string& ca
 
     if (!fSecure)
         LogPrintf("%s: %s\n", strCaption, message);
-    fprintf(stderr, "%s: %s\n", strCaption.c_str(), message.c_str());
+    tfm::format(std::cerr, "%s: %s\n", strCaption.c_str(), message.c_str());
     return false;
 }
 
diff --git a/src/primitives/transaction.h b/src/primitives/transaction.h
index f6f8e313632..aad991e2f15 100644
--- a/src/primitives/transaction.h
+++ b/src/primitives/transaction.h
@@ -222,6 +222,10 @@ inline void UnserializeTransaction(TxType& tx, Stream& s) {
         for (size_t i = 0; i < tx.vin.size(); i++) {
             s >> tx.vin[i].scriptWitness.stack;
         }
+        if (!tx.HasWitness()) {
+            /* It's illegal to encode witnesses when all witness stacks are empty. */
+            throw std::ios_base::failure("Superfluous witness record");
+        }
     }
     if (flags) {
         /* Unknown flag in the serialization */
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 1b063771ef7..d2ac18f5a72 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -437,16 +437,17 @@ int GuiMain(int argc, char* argv[])
     Q_INIT_RESOURCE(bitcoin);
     Q_INIT_RESOURCE(bitcoin_locale);
 
-    BitcoinApplication app(*node, argc, argv);
     // Generate high-dpi pixmaps
     QApplication::setAttribute(Qt::AA_UseHighDpiPixmaps);
 #if QT_VERSION >= 0x050600
-    QGuiApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
+    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
 #endif
 #ifdef Q_OS_MAC
     QApplication::setAttribute(Qt::AA_DontShowIconsInMenus);
 #endif
 
+    BitcoinApplication app(*node, argc, argv);
+
     // Register meta types used for QMetaObject::invokeMethod
     qRegisterMetaType< bool* >();
     //   Need to pass name here as CAmount is a typedef (see http://qt-project.org/doc/qt-5/qmetatype.html#qRegisterMetaType)
diff --git a/src/qt/bitcoingui.cpp b/src/qt/bitcoingui.cpp
index abf9136eee5..8388e8d36e5 100644
--- a/src/qt/bitcoingui.cpp
+++ b/src/qt/bitcoingui.cpp
@@ -335,8 +335,9 @@ void BitcoinGUI::createActions()
     openAction->setStatusTip(tr("Open a bitcoin: URI or payment request"));
 
     m_open_wallet_action = new QAction(tr("Open Wallet"), this);
-    m_open_wallet_action->setMenu(new QMenu(this));
+    m_open_wallet_action->setEnabled(false);
     m_open_wallet_action->setStatusTip(tr("Open a wallet"));
+    m_open_wallet_menu = new QMenu(this);
 
     m_close_wallet_action = new QAction(tr("Close Wallet..."), this);
     m_close_wallet_action->setStatusTip(tr("Close wallet"));
@@ -368,11 +369,20 @@ void BitcoinGUI::createActions()
         connect(usedSendingAddressesAction, &QAction::triggered, walletFrame, &WalletFrame::usedSendingAddresses);
         connect(usedReceivingAddressesAction, &QAction::triggered, walletFrame, &WalletFrame::usedReceivingAddresses);
         connect(openAction, &QAction::triggered, this, &BitcoinGUI::openClicked);
-        connect(m_open_wallet_action->menu(), &QMenu::aboutToShow, [this] {
-            m_open_wallet_action->menu()->clear();
-            for (std::string path : m_wallet_controller->getWalletsAvailableToOpen()) {
+        connect(m_open_wallet_menu, &QMenu::aboutToShow, [this] {
+            m_open_wallet_menu->clear();
+            std::vector<std::string> available_wallets = m_wallet_controller->getWalletsAvailableToOpen();
+            std::vector<std::string> wallets = m_node.listWalletDir();
+            for (const auto& path : wallets) {
                 QString name = path.empty() ? QString("["+tr("default wallet")+"]") : QString::fromStdString(path);
-                QAction* action = m_open_wallet_action->menu()->addAction(name);
+                QAction* action = m_open_wallet_menu->addAction(name);
+
+                if (std::find(available_wallets.begin(), available_wallets.end(), path) == available_wallets.end()) {
+                    // This wallet is already loaded
+                    action->setEnabled(false);
+                    continue;
+                }
+
                 connect(action, &QAction::triggered, [this, name, path] {
                     OpenWalletActivity* activity = m_wallet_controller->openWallet(path);
 
@@ -400,6 +410,10 @@ void BitcoinGUI::createActions()
                     assert(invoked);
                 });
             }
+            if (wallets.empty()) {
+                QAction* action = m_open_wallet_menu->addAction(tr("No wallets available"));
+                action->setEnabled(false);
+            }
         });
         connect(m_close_wallet_action, &QAction::triggered, [this] {
             m_wallet_controller->closeWallet(walletFrame->currentWalletModel(), this);
@@ -620,6 +634,9 @@ void BitcoinGUI::setWalletController(WalletController* wallet_controller)
 
     m_wallet_controller = wallet_controller;
 
+    m_open_wallet_action->setEnabled(true);
+    m_open_wallet_action->setMenu(m_open_wallet_menu);
+
     connect(wallet_controller, &WalletController::walletAdded, this, &BitcoinGUI::addWallet);
     connect(wallet_controller, &WalletController::walletRemoved, this, &BitcoinGUI::removeWallet);
 
@@ -1328,6 +1345,7 @@ void BitcoinGUI::showProgress(const QString &title, int nProgress)
         if (progressDialog) {
             progressDialog->close();
             progressDialog->deleteLater();
+            progressDialog = nullptr;
         }
     } else if (progressDialog) {
         progressDialog->setValue(nProgress);
diff --git a/src/qt/bitcoingui.h b/src/qt/bitcoingui.h
index b58ccbb4552..608f10750af 100644
--- a/src/qt/bitcoingui.h
+++ b/src/qt/bitcoingui.h
@@ -148,6 +148,7 @@ private:
     QAction* openAction = nullptr;
     QAction* showHelpMessageAction = nullptr;
     QAction* m_open_wallet_action{nullptr};
+    QMenu* m_open_wallet_menu{nullptr};
     QAction* m_close_wallet_action{nullptr};
     QAction* m_wallet_selector_label_action = nullptr;
     QAction* m_wallet_selector_action = nullptr;
diff --git a/src/qt/forms/debugwindow.ui b/src/qt/forms/debugwindow.ui
index f0b976001e0..70ad32752a1 100644
--- a/src/qt/forms/debugwindow.ui
+++ b/src/qt/forms/debugwindow.ui
@@ -636,6 +636,9 @@
            <property name="placeholderText">
             <string/>
            </property>
+           <property name="enabled">
+            <bool>false</bool>
+           </property>
           </widget>
          </item>
         </layout>
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index ba0a5abdf31..f6dba1006b9 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -60,6 +60,7 @@
 
 #include <objc/objc-runtime.h>
 #include <CoreServices/CoreServices.h>
+#include <QProcess>
 #endif
 
 namespace GUIUtil {
@@ -392,7 +393,15 @@ bool openBitcoinConf()
     configFile.close();
 
     /* Open bitcoin.conf with the associated application */
-    return QDesktopServices::openUrl(QUrl::fromLocalFile(boostPathToQString(pathConfig)));
+    bool res = QDesktopServices::openUrl(QUrl::fromLocalFile(boostPathToQString(pathConfig)));
+#ifdef Q_OS_MAC
+    // Workaround for macOS-specific behavior; see #15409.
+    if (!res) {
+        res = QProcess::startDetached("/usr/bin/open", QStringList{"-t", boostPathToQString(pathConfig)});
+    }
+#endif
+
+    return res;
 }
 
 ToolTipToRichTextFilter::ToolTipToRichTextFilter(int _size_threshold, QObject *parent) :
diff --git a/src/qt/rpcconsole.cpp b/src/qt/rpcconsole.cpp
index fc1e14b031c..786e36e617b 100644
--- a/src/qt/rpcconsole.cpp
+++ b/src/qt/rpcconsole.cpp
@@ -680,6 +680,9 @@ void RPCConsole::setClientModel(ClientModel *model)
         wordList.sort();
         autoCompleter = new QCompleter(wordList, this);
         autoCompleter->setModelSorting(QCompleter::CaseSensitivelySortedModel);
+        // ui->lineEdit is initially disabled because running commands is only
+        // possible from now on.
+        ui->lineEdit->setEnabled(true);
         ui->lineEdit->setCompleter(autoCompleter);
         autoCompleter->popup()->installEventFilter(this);
         // Start thread to execute RPC commands.
diff --git a/src/qt/utilitydialog.cpp b/src/qt/utilitydialog.cpp
index b051dd159b6..2a13c460139 100644
--- a/src/qt/utilitydialog.cpp
+++ b/src/qt/utilitydialog.cpp
@@ -129,7 +129,7 @@ HelpMessageDialog::~HelpMessageDialog()
 void HelpMessageDialog::printToConsole()
 {
     // On other operating systems, the expected action is to print the message to the console.
-    fprintf(stdout, "%s\n", qPrintable(text));
+    tfm::format(std::cout, "%s\n", qPrintable(text));
 }
 
 void HelpMessageDialog::showOrPrint()
diff --git a/src/qt/walletview.cpp b/src/qt/walletview.cpp
index 5f6f93d9481..be47f67f950 100644
--- a/src/qt/walletview.cpp
+++ b/src/qt/walletview.cpp
@@ -316,6 +316,7 @@ void WalletView::showProgress(const QString &title, int nProgress)
         if (progressDialog) {
             progressDialog->close();
             progressDialog->deleteLater();
+            progressDialog = nullptr;
         }
     } else if (progressDialog) {
         if (progressDialog->wasCanceled()) {
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index 6fa472d4426..bd351630748 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -1030,7 +1030,12 @@ static UniValue pruneblockchain(const JSONRPCRequest& request)
     }
 
     PruneBlockFilesManual(height);
-    return uint64_t(height);
+    const CBlockIndex* block = ::chainActive.Tip();
+    assert(block);
+    while (block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA)) {
+        block = block->pprev;
+    }
+    return uint64_t(block->nHeight);
 }
 
 static UniValue gettxoutsetinfo(const JSONRPCRequest& request)
diff --git a/src/rpc/misc.cpp b/src/rpc/misc.cpp
index 0a97f802974..780a10e03ff 100644
--- a/src/rpc/misc.cpp
+++ b/src/rpc/misc.cpp
@@ -128,9 +128,9 @@ static UniValue createmultisig(const JSONRPCRequest& request)
     }
 
     // Construct using pay-to-script-hash:
-    const CScript inner = CreateMultisigRedeemscript(required, pubkeys);
     CBasicKeyStore keystore;
-    const CTxDestination dest = AddAndGetDestinationForScript(keystore, inner, output_type);
+    CScript inner;
+    const CTxDestination dest = AddAndGetMultisigDestination(required, pubkeys, output_type, keystore, inner);
 
     UniValue result(UniValue::VOBJ);
     result.pushKV("address", EncodeDestination(dest));
diff --git a/src/rpc/net.cpp b/src/rpc/net.cpp
index c7b3478f440..a5f590757d2 100644
--- a/src/rpc/net.cpp
+++ b/src/rpc/net.cpp
@@ -495,7 +495,7 @@ static UniValue getnetworkinfo(const JSONRPCRequest& request)
     obj.pushKV("protocolversion",PROTOCOL_VERSION);
     if(g_connman)
         obj.pushKV("localservices", strprintf("%016x", g_connman->GetLocalServices()));
-    obj.pushKV("localrelay",     fRelayTxes);
+    obj.pushKV("localrelay", g_relay_txes);
     obj.pushKV("timeoffset",    GetTimeOffset());
     if (g_connman) {
         obj.pushKV("networkactive", g_connman->GetNetworkActive());
diff --git a/src/rpc/rawtransaction.cpp b/src/rpc/rawtransaction.cpp
index 71acdbfb991..ae4fed285a9 100644
--- a/src/rpc/rawtransaction.cpp
+++ b/src/rpc/rawtransaction.cpp
@@ -535,14 +535,17 @@ static UniValue createrawtransaction(const JSONRPCRequest& request)
 
 static UniValue decoderawtransaction(const JSONRPCRequest& request)
 {
-    if (request.fHelp || request.params.size() < 1 || request.params.size() > 2)
-        throw std::runtime_error(
-            RPCHelpMan{"decoderawtransaction",
+    const RPCHelpMan help{"decoderawtransaction",
                 "\nReturn a JSON object representing the serialized, hex-encoded transaction.\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The transaction hex string"},
-                    {"iswitness", RPCArg::Type::BOOL, /* default */ "depends on heuristic tests", "Whether the transaction hex is a serialized witness transaction\n"
-            "                         If iswitness is not present, heuristic tests will be used in decoding"},
+                    {"iswitness", RPCArg::Type::BOOL, /* default */ "depends on heuristic tests", "Whether the transaction hex is a serialized witness transaction.\n"
+                        "If iswitness is not present, heuristic tests will be used in decoding.\n"
+                        "If true, only witness deserialization will be tried.\n"
+                        "If false, only non-witness deserialization will be tried.\n"
+                        "This boolean should reflect whether the transaction has inputs\n"
+                        "(e.g. fully valid, or on-chain transactions), if known by the caller."
+                    },
                 },
                 RPCResult{
             "{\n"
@@ -589,7 +592,11 @@ static UniValue decoderawtransaction(const JSONRPCRequest& request)
                     HelpExampleCli("decoderawtransaction", "\"hexstring\"")
             + HelpExampleRpc("decoderawtransaction", "\"hexstring\"")
                 },
-            }.ToString());
+    };
+
+    if (request.fHelp || !help.IsValidNumArgs(request.params.size())) {
+        throw std::runtime_error(help.ToString());
+    }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VBOOL});
 
@@ -996,8 +1003,8 @@ static UniValue signrawtransactionwithkey(const JSONRPCRequest& request)
             "}\n"
                 },
                 RPCExamples{
-                    HelpExampleCli("signrawtransactionwithkey", "\"myhex\"")
-            + HelpExampleRpc("signrawtransactionwithkey", "\"myhex\"")
+                    HelpExampleCli("signrawtransactionwithkey", "\"myhex\" \"[\\\"key1\\\",\\\"key2\\\"]\"")
+            + HelpExampleRpc("signrawtransactionwithkey", "\"myhex\", \"[\\\"key1\\\",\\\"key2\\\"]\"")
                 },
             }.ToString());
 
@@ -1643,19 +1650,20 @@ UniValue createpsbt(const JSONRPCRequest& request)
 
 UniValue converttopsbt(const JSONRPCRequest& request)
 {
-    if (request.fHelp || request.params.size() < 1 || request.params.size() > 3)
-        throw std::runtime_error(
-            RPCHelpMan{"converttopsbt",
+    const RPCHelpMan help{"converttopsbt",
                 "\nConverts a network serialized transaction to a PSBT. This should be used only with createrawtransaction and fundrawtransaction\n"
                 "createpsbt and walletcreatefundedpsbt should be used for new applications.\n",
                 {
                     {"hexstring", RPCArg::Type::STR_HEX, RPCArg::Optional::NO, "The hex string of a raw transaction"},
-                    {"permitsigdata", RPCArg::Type::BOOL, /* default */ "false", "If true, any signatures in the input will be discarded and conversion.\n"
+                    {"permitsigdata", RPCArg::Type::BOOL, /* default */ "false", "If true, any signatures in the input will be discarded and conversion\n"
                             "                              will continue. If false, RPC will fail if any signatures are present."},
                     {"iswitness", RPCArg::Type::BOOL, /* default */ "depends on heuristic tests", "Whether the transaction hex is a serialized witness transaction.\n"
-                            "                              If iswitness is not present, heuristic tests will be used in decoding. If true, only witness deserializaion\n"
-                            "                              will be tried. If false, only non-witness deserialization will be tried. Only has an effect if\n"
-                            "                              permitsigdata is true."},
+                        "If iswitness is not present, heuristic tests will be used in decoding.\n"
+                        "If true, only witness deserialization will be tried.\n"
+                        "If false, only non-witness deserialization will be tried.\n"
+                        "This boolean should reflect whether the transaction has inputs\n"
+                        "(e.g. fully valid, or on-chain transactions), if known by the caller."
+                    },
                 },
                 RPCResult{
                             "  \"psbt\"        (string)  The resulting raw transaction (base64-encoded string)\n"
@@ -1666,8 +1674,11 @@ UniValue converttopsbt(const JSONRPCRequest& request)
                             "\nConvert the transaction to a PSBT\n"
                             + HelpExampleCli("converttopsbt", "\"rawtransaction\"")
                 },
-            }.ToString());
+    };
 
+    if (request.fHelp || !help.IsValidNumArgs(request.params.size())) {
+        throw std::runtime_error(help.ToString());
+    }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValue::VBOOL, UniValue::VBOOL}, true);
 
@@ -1676,8 +1687,8 @@ UniValue converttopsbt(const JSONRPCRequest& request)
     bool permitsigdata = request.params[1].isNull() ? false : request.params[1].get_bool();
     bool witness_specified = !request.params[2].isNull();
     bool iswitness = witness_specified ? request.params[2].get_bool() : false;
-    bool try_witness = permitsigdata ? (witness_specified ? iswitness : true) : false;
-    bool try_no_witness = permitsigdata ? (witness_specified ? !iswitness : true) : true;
+    const bool try_witness = witness_specified ? iswitness : true;
+    const bool try_no_witness = witness_specified ? !iswitness : true;
     if (!DecodeHexTx(tx, request.params[0].get_str(), try_no_witness, try_witness)) {
         throw JSONRPCError(RPC_DESERIALIZATION_ERROR, "TX decode failed");
     }
diff --git a/src/rpc/util.cpp b/src/rpc/util.cpp
index 40ac1331863..ff832810bcf 100644
--- a/src/rpc/util.cpp
+++ b/src/rpc/util.cpp
@@ -5,6 +5,7 @@
 #include <key_io.h>
 #include <keystore.h>
 #include <policy/fees.h>
+#include <outputtype.h>
 #include <rpc/util.h>
 #include <tinyformat.h>
 #include <util/strencodings.h>
@@ -46,8 +47,8 @@ CPubKey AddrToPubKey(CKeyStore* const keystore, const std::string& addr_in)
     return vchPubKey;
 }
 
-// Creates a multisig redeemscript from a given list of public keys and number required.
-CScript CreateMultisigRedeemscript(const int required, const std::vector<CPubKey>& pubkeys)
+// Creates a multisig address from a given list of public keys, number of signatures required, and the address type
+CTxDestination AddAndGetMultisigDestination(const int required, const std::vector<CPubKey>& pubkeys, OutputType type, CKeyStore& keystore, CScript& script_out)
 {
     // Gather public keys
     if (required < 1) {
@@ -60,13 +61,24 @@ CScript CreateMultisigRedeemscript(const int required, const std::vector<CPubKey
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Number of keys involved in the multisignature address creation > 16\nReduce the number");
     }
 
-    CScript result = GetScriptForMultisig(required, pubkeys);
+    script_out = GetScriptForMultisig(required, pubkeys);
 
-    if (result.size() > MAX_SCRIPT_ELEMENT_SIZE) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, (strprintf("redeemScript exceeds size limit: %d > %d", result.size(), MAX_SCRIPT_ELEMENT_SIZE)));
+    if (script_out.size() > MAX_SCRIPT_ELEMENT_SIZE) {
+        throw JSONRPCError(RPC_INVALID_PARAMETER, (strprintf("redeemScript exceeds size limit: %d > %d", script_out.size(), MAX_SCRIPT_ELEMENT_SIZE)));
     }
 
-    return result;
+    // Check if any keys are uncompressed. If so, the type is legacy
+    for (const CPubKey& pk : pubkeys) {
+        if (!pk.IsCompressed()) {
+            type = OutputType::LEGACY;
+            break;
+        }
+    }
+
+    // Make the address
+    CTxDestination dest = AddAndGetDestinationForScript(keystore, script_out, type);
+
+    return dest;
 }
 
 class DescribeAddressVisitor : public boost::static_visitor<UniValue>
diff --git a/src/rpc/util.h b/src/rpc/util.h
index f1bd2c89dfc..d4d8694053a 100644
--- a/src/rpc/util.h
+++ b/src/rpc/util.h
@@ -6,6 +6,7 @@
 #define BITCOIN_RPC_UTIL_H
 
 #include <node/transaction.h>
+#include <outputtype.h>
 #include <pubkey.h>
 #include <rpc/protocol.h>
 #include <script/standard.h>
@@ -28,7 +29,7 @@ extern InitInterfaces* g_rpc_interfaces;
 
 CPubKey HexToPubKey(const std::string& hex_in);
 CPubKey AddrToPubKey(CKeyStore* const keystore, const std::string& addr_in);
-CScript CreateMultisigRedeemscript(const int required, const std::vector<CPubKey>& pubkeys);
+CTxDestination AddAndGetMultisigDestination(const int required, const std::vector<CPubKey>& pubkeys, OutputType type, CKeyStore& keystore, CScript& script_out);
 
 UniValue DescribeAddress(const CTxDestination& dest);
 
diff --git a/src/sync.cpp b/src/sync.cpp
index 23ca866e530..9c42d568af0 100644
--- a/src/sync.cpp
+++ b/src/sync.cpp
@@ -105,7 +105,7 @@ static void potential_deadlock_detected(const std::pair<void*, void*>& mismatch,
         LogPrintf(" %s\n", i.second.ToString());
     }
     if (g_debug_lockorder_abort) {
-        fprintf(stderr, "Assertion failed: detected inconsistent lock order at %s:%i, details in debug log.\n", __FILE__, __LINE__);
+        tfm::format(std::cerr, "Assertion failed: detected inconsistent lock order at %s:%i, details in debug log.\n", __FILE__, __LINE__);
         abort();
     }
     throw std::logic_error("potential deadlock detected");
@@ -162,7 +162,7 @@ void AssertLockHeldInternal(const char* pszName, const char* pszFile, int nLine,
     for (const std::pair<void*, CLockLocation>& i : g_lockstack)
         if (i.first == cs)
             return;
-    fprintf(stderr, "Assertion failed: lock %s not held in %s:%i; locks held:\n%s", pszName, pszFile, nLine, LocksHeld().c_str());
+    tfm::format(std::cerr, "Assertion failed: lock %s not held in %s:%i; locks held:\n%s", pszName, pszFile, nLine, LocksHeld().c_str());
     abort();
 }
 
@@ -170,7 +170,7 @@ void AssertLockNotHeldInternal(const char* pszName, const char* pszFile, int nLi
 {
     for (const std::pair<void*, CLockLocation>& i : g_lockstack) {
         if (i.first == cs) {
-            fprintf(stderr, "Assertion failed: lock %s held in %s:%i; locks held:\n%s", pszName, pszFile, nLine, LocksHeld().c_str());
+            tfm::format(std::cerr, "Assertion failed: lock %s held in %s:%i; locks held:\n%s", pszName, pszFile, nLine, LocksHeld().c_str());
             abort();
         }
     }
diff --git a/src/test/compilerbug_tests.cpp b/src/test/compilerbug_tests.cpp
new file mode 100644
index 00000000000..701671314f2
--- /dev/null
+++ b/src/test/compilerbug_tests.cpp
@@ -0,0 +1,43 @@
+// Copyright (c) 2019 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <test/test_bitcoin.h>
+#include <boost/test/unit_test.hpp>
+
+BOOST_FIXTURE_TEST_SUITE(compilerbug_tests, BasicTestingSetup)
+
+#if defined(__GNUC__)
+// This block will also be built under clang, which is fine (as it supports noinline)
+void __attribute__ ((noinline)) set_one(unsigned char* ptr)
+{
+    *ptr = 1;
+}
+
+int __attribute__ ((noinline)) check_zero(unsigned char const* in, unsigned int len)
+{
+    for (unsigned int i = 0; i < len; ++i) {
+        if (in[i] != 0) return 0;
+    }
+    return 1;
+}
+
+void set_one_on_stack() {
+    unsigned char buf[1];
+    set_one(buf);
+}
+
+BOOST_AUTO_TEST_CASE(gccbug_90348) {
+    // Test for GCC bug 90348. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90348
+    for (int i = 0; i <= 4; ++i) {
+        unsigned char in[4];
+        for (int j = 0; j < i; ++j) {
+            in[j] = 0;
+            set_one_on_stack(); // Apparently modifies in[0]
+        }
+        BOOST_CHECK(check_zero(in, i));
+    }
+}
+#endif
+
+BOOST_AUTO_TEST_SUITE_END()
diff --git a/src/tinyformat.h b/src/tinyformat.h
index 14b7cd30262..182f518a0b5 100644
--- a/src/tinyformat.h
+++ b/src/tinyformat.h
@@ -1063,6 +1063,7 @@ std::string format(const std::string &fmt, const Args&... args)
 
 } // namespace tinyformat
 
+/** Format arguments and return the string or write to given std::ostream (see tinyformat::format doc for details) */
 #define strprintf tfm::format
 
 #endif // TINYFORMAT_H_INCLUDED
diff --git a/src/util/system.cpp b/src/util/system.cpp
index 6e82de743af..7ccb9ef9e79 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -675,7 +675,7 @@ void PrintExceptionContinue(const std::exception* pex, const char* pszThread)
 {
     std::string message = FormatException(pex, pszThread);
     LogPrintf("\n\n************************\n%s\n", message);
-    fprintf(stderr, "\n\n************************\n%s\n", message.c_str());
+    tfm::format(std::cerr, "\n\n************************\n%s\n", message.c_str());
 }
 
 fs::path GetDefaultDataDir()
@@ -935,7 +935,7 @@ bool ArgsManager::ReadConfigFiles(std::string& error, bool ignore_invalid_keys)
                 }
             }
             for (const std::string& to_include : includeconf) {
-                fprintf(stderr, "warning: -includeconf cannot be used from included files; ignoring -includeconf=%s\n", to_include.c_str());
+                tfm::format(std::cerr, "warning: -includeconf cannot be used from included files; ignoring -includeconf=%s\n", to_include.c_str());
             }
         }
     }
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 9393d86577c..a9a8c2e1855 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -1028,8 +1028,8 @@ static UniValue addmultisigaddress(const JSONRPCRequest& request)
     }
 
     // Construct using pay-to-script-hash:
-    CScript inner = CreateMultisigRedeemscript(required, pubkeys);
-    CTxDestination dest = AddAndGetDestinationForScript(*pwallet, inner, output_type);
+    CScript inner;
+    CTxDestination dest = AddAndGetMultisigDestination(required, pubkeys, output_type, *pwallet, inner);
     pwallet->SetAddressBook(dest, label, "send");
 
     UniValue result(UniValue::VOBJ);
@@ -3040,9 +3040,7 @@ static UniValue fundrawtransaction(const JSONRPCRequest& request)
         return NullUniValue;
     }
 
-    if (request.fHelp || request.params.size() < 1 || request.params.size() > 3)
-        throw std::runtime_error(
-            RPCHelpMan{"fundrawtransaction",
+    const RPCHelpMan help{"fundrawtransaction",
                 "\nAdd inputs to a transaction until it has enough in value to meet its out value.\n"
                 "This will not modify existing inputs, and will add at most one change output to the outputs.\n"
                 "No existing outputs will be modified unless \"subtractFeeFromOutputs\" is specified.\n"
@@ -3081,8 +3079,13 @@ static UniValue fundrawtransaction(const JSONRPCRequest& request)
                             "         \"CONSERVATIVE\""},
                         },
                         "options"},
-                    {"iswitness", RPCArg::Type::BOOL, /* default */ "depends on heuristic tests", "Whether the transaction hex is a serialized witness transaction \n"
-                            "                              If iswitness is not present, heuristic tests will be used in decoding"},
+                    {"iswitness", RPCArg::Type::BOOL, /* default */ "depends on heuristic tests", "Whether the transaction hex is a serialized witness transaction.\n"
+                        "If iswitness is not present, heuristic tests will be used in decoding.\n"
+                        "If true, only witness deserialization will be tried.\n"
+                        "If false, only non-witness deserialization will be tried.\n"
+                        "This boolean should reflect whether the transaction has inputs\n"
+                        "(e.g. fully valid, or on-chain transactions), if known by the caller."
+                    },
                 },
                 RPCResult{
                             "{\n"
@@ -3101,7 +3104,11 @@ static UniValue fundrawtransaction(const JSONRPCRequest& request)
                             "\nSend the transaction\n"
                             + HelpExampleCli("sendrawtransaction", "\"signedtransactionhex\"")
                                 },
-                            }.ToString());
+    };
+
+    if (request.fHelp || !help.IsValidNumArgs(request.params.size())) {
+        throw std::runtime_error(help.ToString());
+    }
 
     RPCTypeCheck(request.params, {UniValue::VSTR, UniValueType(), UniValue::VBOOL});
 
diff --git a/src/wallet/wallettool.cpp b/src/wallet/wallettool.cpp
index 797f051189b..d460c514e03 100644
--- a/src/wallet/wallettool.cpp
+++ b/src/wallet/wallettool.cpp
@@ -24,7 +24,7 @@ static void WalletToolReleaseWallet(CWallet* wallet)
 static std::shared_ptr<CWallet> CreateWallet(const std::string& name, const fs::path& path)
 {
     if (fs::exists(path)) {
-        fprintf(stderr, "Error: File exists already\n");
+        tfm::format(std::cerr, "Error: File exists already\n");
         return nullptr;
     }
     // dummy chain interface
@@ -33,7 +33,7 @@ static std::shared_ptr<CWallet> CreateWallet(const std::string& name, const fs::
     bool first_run = true;
     DBErrors load_wallet_ret = wallet_instance->LoadWallet(first_run);
     if (load_wallet_ret != DBErrors::LOAD_OK) {
-        fprintf(stderr, "Error creating %s", name.c_str());
+        tfm::format(std::cerr, "Error creating %s", name.c_str());
         return nullptr;
     }
 
@@ -43,7 +43,7 @@ static std::shared_ptr<CWallet> CreateWallet(const std::string& name, const fs::
     CPubKey seed = wallet_instance->GenerateNewSeed();
     wallet_instance->SetHDSeed(seed);
 
-    fprintf(stdout, "Topping up keypool...\n");
+    tfm::format(std::cout, "Topping up keypool...\n");
     wallet_instance->TopUpKeyPool();
     return wallet_instance;
 }
@@ -51,7 +51,7 @@ static std::shared_ptr<CWallet> CreateWallet(const std::string& name, const fs::
 static std::shared_ptr<CWallet> LoadWallet(const std::string& name, const fs::path& path)
 {
     if (!fs::exists(path)) {
-        fprintf(stderr, "Error: Wallet files does not exist\n");
+        tfm::format(std::cerr, "Error: Wallet files does not exist\n");
         return nullptr;
     }
 
@@ -62,29 +62,29 @@ static std::shared_ptr<CWallet> LoadWallet(const std::string& name, const fs::pa
     try {
         bool first_run;
         load_wallet_ret = wallet_instance->LoadWallet(first_run);
-    } catch (const std::runtime_error) {
-        fprintf(stderr, "Error loading %s. Is wallet being used by another process?\n", name.c_str());
+    } catch (const std::runtime_error&) {
+        tfm::format(std::cerr, "Error loading %s. Is wallet being used by another process?\n", name.c_str());
         return nullptr;
     }
 
     if (load_wallet_ret != DBErrors::LOAD_OK) {
         wallet_instance = nullptr;
         if (load_wallet_ret == DBErrors::CORRUPT) {
-            fprintf(stderr, "Error loading %s: Wallet corrupted", name.c_str());
+            tfm::format(std::cerr, "Error loading %s: Wallet corrupted", name.c_str());
             return nullptr;
         } else if (load_wallet_ret == DBErrors::NONCRITICAL_ERROR) {
-            fprintf(stderr, "Error reading %s! All keys read correctly, but transaction data"
+            tfm::format(std::cerr, "Error reading %s! All keys read correctly, but transaction data"
                             " or address book entries might be missing or incorrect.",
                 name.c_str());
         } else if (load_wallet_ret == DBErrors::TOO_NEW) {
-            fprintf(stderr, "Error loading %s: Wallet requires newer version of %s",
+            tfm::format(std::cerr, "Error loading %s: Wallet requires newer version of %s",
                 name.c_str(), PACKAGE_NAME);
             return nullptr;
         } else if (load_wallet_ret == DBErrors::NEED_REWRITE) {
-            fprintf(stderr, "Wallet needed to be rewritten: restart %s to complete", PACKAGE_NAME);
+            tfm::format(std::cerr, "Wallet needed to be rewritten: restart %s to complete", PACKAGE_NAME);
             return nullptr;
         } else {
-            fprintf(stderr, "Error loading %s", name.c_str());
+            tfm::format(std::cerr, "Error loading %s", name.c_str());
             return nullptr;
         }
     }
@@ -96,12 +96,12 @@ static void WalletShowInfo(CWallet* wallet_instance)
 {
     LOCK(wallet_instance->cs_wallet);
 
-    fprintf(stdout, "Wallet info\n===========\n");
-    fprintf(stdout, "Encrypted: %s\n", wallet_instance->IsCrypted() ? "yes" : "no");
-    fprintf(stdout, "HD (hd seed available): %s\n", wallet_instance->GetHDChain().seed_id.IsNull() ? "no" : "yes");
-    fprintf(stdout, "Keypool Size: %u\n", wallet_instance->GetKeyPoolSize());
-    fprintf(stdout, "Transactions: %zu\n", wallet_instance->mapWallet.size());
-    fprintf(stdout, "Address Book: %zu\n", wallet_instance->mapAddressBook.size());
+    tfm::format(std::cout, "Wallet info\n===========\n");
+    tfm::format(std::cout, "Encrypted: %s\n", wallet_instance->IsCrypted() ? "yes" : "no");
+    tfm::format(std::cout, "HD (hd seed available): %s\n", wallet_instance->GetHDChain().seed_id.IsNull() ? "no" : "yes");
+    tfm::format(std::cout, "Keypool Size: %u\n", wallet_instance->GetKeyPoolSize());
+    tfm::format(std::cout, "Transactions: %zu\n", wallet_instance->mapWallet.size());
+    tfm::format(std::cout, "Address Book: %zu\n", wallet_instance->mapAddressBook.size());
 }
 
 bool ExecuteWalletToolFunc(const std::string& command, const std::string& name)
@@ -116,12 +116,12 @@ bool ExecuteWalletToolFunc(const std::string& command, const std::string& name)
         }
     } else if (command == "info") {
         if (!fs::exists(path)) {
-            fprintf(stderr, "Error: no wallet file at %s\n", name.c_str());
+            tfm::format(std::cerr, "Error: no wallet file at %s\n", name.c_str());
             return false;
         }
         std::string error;
         if (!WalletBatch::VerifyEnvironment(path, error)) {
-            fprintf(stderr, "Error loading %s. Is wallet being used by other process?\n", name.c_str());
+            tfm::format(std::cerr, "Error loading %s. Is wallet being used by other process?\n", name.c_str());
             return false;
         }
         std::shared_ptr<CWallet> wallet_instance = LoadWallet(name, path);
@@ -129,7 +129,7 @@ bool ExecuteWalletToolFunc(const std::string& command, const std::string& name)
         WalletShowInfo(wallet_instance.get());
         wallet_instance->Flush(true);
     } else {
-        fprintf(stderr, "Invalid command: %s\n", command.c_str());
+        tfm::format(std::cerr, "Invalid command: %s\n", command.c_str());
         return false;
     }
 
diff --git a/test/functional/data/invalid_txs.py b/test/functional/data/invalid_txs.py
index 02deae92f33..d262dae5aa4 100644
--- a/test/functional/data/invalid_txs.py
+++ b/test/functional/data/invalid_txs.py
@@ -71,9 +71,13 @@ class InputMissing(BadTxTemplate):
     reject_reason = "bad-txns-vin-empty"
     expect_disconnect = False
 
+    # We use a blank transaction here to make sure
+    # it is interpreted as a non-witness transaction.
+    # Otherwise the transaction will fail the
+    # "surpufluous witness" check during deserialization
+    # rather than the input count check.
     def get_tx(self):
         tx = CTransaction()
-        tx.vout.append(CTxOut(0, sc.CScript([sc.OP_TRUE] * 100)))
         tx.calc_sha256()
         return tx
 
diff --git a/test/functional/feature_assumevalid.py b/test/functional/feature_assumevalid.py
index 0eb3dd440bc..7d6a56919d1 100755
--- a/test/functional/feature_assumevalid.py
+++ b/test/functional/feature_assumevalid.py
@@ -32,7 +32,7 @@ Start three nodes:
 import time
 
 from test_framework.blocktools import (create_block, create_coinbase)
-from test_framework.key import CECKey
+from test_framework.key import ECKey
 from test_framework.messages import (
     CBlockHeader,
     COutPoint,
@@ -104,9 +104,9 @@ class AssumeValidTest(BitcoinTestFramework):
         self.blocks = []
 
         # Get a pubkey for the coinbase TXO
-        coinbase_key = CECKey()
-        coinbase_key.set_secretbytes(b"horsebattery")
-        coinbase_pubkey = coinbase_key.get_pubkey()
+        coinbase_key = ECKey()
+        coinbase_key.generate()
+        coinbase_pubkey = coinbase_key.get_pubkey().get_bytes()
 
         # Create the first block with a coinbase output to our key
         height = 1
diff --git a/test/functional/feature_block.py b/test/functional/feature_block.py
index 5253ff7aaa7..1aa5ae1423e 100755
--- a/test/functional/feature_block.py
+++ b/test/functional/feature_block.py
@@ -14,7 +14,7 @@ from test_framework.blocktools import (
     get_legacy_sigopcount_block,
     MAX_BLOCK_SIGOPS,
 )
-from test_framework.key import CECKey
+from test_framework.key import ECKey
 from test_framework.messages import (
     CBlock,
     COIN,
@@ -86,9 +86,9 @@ class FullBlockTest(BitcoinTestFramework):
         self.bootstrap_p2p()  # Add one p2p connection to the node
 
         self.block_heights = {}
-        self.coinbase_key = CECKey()
-        self.coinbase_key.set_secretbytes(b"horsebattery")
-        self.coinbase_pubkey = self.coinbase_key.get_pubkey()
+        self.coinbase_key = ECKey()
+        self.coinbase_key.generate()
+        self.coinbase_pubkey = self.coinbase_key.get_pubkey().get_bytes()
         self.tip = None
         self.blocks = {}
         self.genesis_hash = int(self.nodes[0].getbestblockhash(), 16)
@@ -146,20 +146,6 @@ class FullBlockTest(BitcoinTestFramework):
             badtx = template.get_tx()
             if TxTemplate != invalid_txs.InputMissing:
                 self.sign_tx(badtx, attempt_spend_tx)
-            else:
-                # Segwit is active in regtest at this point, so to deserialize a
-                # transaction without any inputs correctly, we set the outputs
-                # to an empty list. This is a hack, as the serialization of an
-                # empty list of outputs is deserialized as flags==0 and thus
-                # deserialization of the outputs is skipped.
-                # A policy check requires "loose" txs to be of a minimum size,
-                # so vtx is not set to be empty in the TxTemplate class and we
-                # only apply the workaround where txs are not "loose", i.e. in
-                # blocks.
-                #
-                # The workaround has the purpose that both sides calculate
-                # the same tx hash in the merkle tree
-                badtx.vout = []
             badtx.rehash()
             badblock = self.update_block(blockname, [badtx])
             self.sync_blocks(
@@ -528,7 +514,7 @@ class FullBlockTest(BitcoinTestFramework):
             tx.vin.append(CTxIn(COutPoint(b39.vtx[i].sha256, 0), b''))
             # Note: must pass the redeem_script (not p2sh_script) to the signature hash function
             (sighash, err) = SignatureHash(redeem_script, tx, 1, SIGHASH_ALL)
-            sig = self.coinbase_key.sign(sighash) + bytes(bytearray([SIGHASH_ALL]))
+            sig = self.coinbase_key.sign_ecdsa(sighash) + bytes(bytearray([SIGHASH_ALL]))
             scriptSig = CScript([sig, redeem_script])
 
             tx.vin[1].scriptSig = scriptSig
@@ -1284,7 +1270,7 @@ class FullBlockTest(BitcoinTestFramework):
             tx.vin[0].scriptSig = CScript()
             return
         (sighash, err) = SignatureHash(spend_tx.vout[0].scriptPubKey, tx, 0, SIGHASH_ALL)
-        tx.vin[0].scriptSig = CScript([self.coinbase_key.sign(sighash) + bytes(bytearray([SIGHASH_ALL]))])
+        tx.vin[0].scriptSig = CScript([self.coinbase_key.sign_ecdsa(sighash) + bytes(bytearray([SIGHASH_ALL]))])
 
     def create_and_sign_transaction(self, spend_tx, value, script=CScript([OP_TRUE])):
         tx = self.create_tx(spend_tx, 0, value, script)
diff --git a/test/functional/feature_pruning.py b/test/functional/feature_pruning.py
index 3e1ba88f0ad..b3dd699fda9 100755
--- a/test/functional/feature_pruning.py
+++ b/test/functional/feature_pruning.py
@@ -10,12 +10,10 @@ This test takes 30 mins or more (up to 2 hours)
 """
 
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import assert_equal, assert_greater_than, assert_raises_rpc_error, connect_nodes, mine_large_block, sync_blocks, wait_until
+from test_framework.util import assert_equal, assert_raises_rpc_error, connect_nodes, mine_large_block, sync_blocks, wait_until
 
 import os
 
-MIN_BLOCKS_TO_KEEP = 288
-
 # Rescans start at the earliest block up to 2 hours before a key timestamp, so
 # the manual prune RPC avoids pruning blocks in the same window to be
 # compatible with pruning based on key creation time.
@@ -250,20 +248,9 @@ class PruneTest(BitcoinTestFramework):
             else:
                 return index
 
-        def prune(index, expected_ret=None):
+        def prune(index):
             ret = node.pruneblockchain(height=height(index))
-            # Check the return value. When use_timestamp is True, just check
-            # that the return value is less than or equal to the expected
-            # value, because when more than one block is generated per second,
-            # a timestamp will not be granular enough to uniquely identify an
-            # individual block.
-            if expected_ret is None:
-                expected_ret = index
-            if use_timestamp:
-                assert_greater_than(ret, 0)
-                assert_greater_than(expected_ret + 1, ret)
-            else:
-                assert_equal(ret, expected_ret)
+            assert_equal(ret, node.getblockchaininfo()['pruneheight'])
 
         def has_block(index):
             return os.path.isfile(os.path.join(self.nodes[node_number].datadir, "regtest", "blocks", "blk{:05}.dat".format(index)))
@@ -308,7 +295,7 @@ class PruneTest(BitcoinTestFramework):
             raise AssertionError("blk00001.dat is still there, should be pruned by now")
 
         # height=1000 should not prune anything more, because tip-288 is in blk00002.dat.
-        prune(1000, 1001 - MIN_BLOCKS_TO_KEEP)
+        prune(1000)
         if not has_block(2):
             raise AssertionError("blk00002.dat is still there, should be pruned by now")
 
diff --git a/test/functional/p2p_blocksonly.py b/test/functional/p2p_blocksonly.py
new file mode 100755
index 00000000000..12cb06a4079
--- /dev/null
+++ b/test/functional/p2p_blocksonly.py
@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+# Copyright (c) 2019 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test p2p blocksonly"""
+
+from test_framework.messages import msg_tx, CTransaction, FromHex
+from test_framework.mininode import P2PInterface
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+
+class P2PBlocksOnly(BitcoinTestFramework):
+    def set_test_params(self):
+        self.setup_clean_chain = False
+        self.num_nodes = 1
+        self.extra_args = [["-blocksonly"]]
+
+    def run_test(self):
+        self.nodes[0].add_p2p_connection(P2PInterface())
+
+        self.log.info('Check that txs from p2p are rejected')
+        prevtx = self.nodes[0].getblock(self.nodes[0].getblockhash(1), 2)['tx'][0]
+        rawtx = self.nodes[0].createrawtransaction(
+            inputs=[{
+                'txid': prevtx['txid'],
+                'vout': 0
+            }],
+            outputs=[{
+                self.nodes[0].get_deterministic_priv_key().address: 50 - 0.00125
+            }],
+        )
+        sigtx = self.nodes[0].signrawtransactionwithkey(
+            hexstring=rawtx,
+            privkeys=[self.nodes[0].get_deterministic_priv_key().key],
+            prevtxs=[{
+                'txid': prevtx['txid'],
+                'vout': 0,
+                'scriptPubKey': prevtx['vout'][0]['scriptPubKey']['hex'],
+            }],
+        )['hex']
+        assert_equal(self.nodes[0].getnetworkinfo()['localrelay'], False)
+        with self.nodes[0].assert_debug_log(['transaction sent in violation of protocol peer=0']):
+            self.nodes[0].p2p.send_message(msg_tx(FromHex(CTransaction(), sigtx)))
+            self.nodes[0].p2p.sync_with_ping()
+            assert_equal(self.nodes[0].getmempoolinfo()['size'], 0)
+
+        self.log.info('Check that txs from rpc are not rejected and relayed to other peers')
+        assert_equal(self.nodes[0].getpeerinfo()[0]['relaytxes'], True)
+        txid = self.nodes[0].testmempoolaccept([sigtx])[0]['txid']
+        with self.nodes[0].assert_debug_log(['received getdata for: tx {} peer=0'.format(txid)]):
+            self.nodes[0].sendrawtransaction(sigtx)
+            self.nodes[0].p2p.wait_for_tx(txid)
+            assert_equal(self.nodes[0].getmempoolinfo()['size'], 1)
+
+
+if __name__ == '__main__':
+    P2PBlocksOnly().main()
diff --git a/test/functional/p2p_segwit.py b/test/functional/p2p_segwit.py
index 8f8e89cf15c..62b12507ed3 100755
--- a/test/functional/p2p_segwit.py
+++ b/test/functional/p2p_segwit.py
@@ -10,7 +10,7 @@ import struct
 import time
 
 from test_framework.blocktools import create_block, create_coinbase, add_witness_commitment, get_witness_script, WITNESS_COMMITMENT_HEADER
-from test_framework.key import CECKey, CPubKey
+from test_framework.key import ECKey
 from test_framework.messages import (
     BIP125_SEQUENCE_NUMBER,
     CBlock,
@@ -37,6 +37,7 @@ from test_framework.messages import (
     ser_vector,
     sha256,
     uint256_from_str,
+    FromHex,
 )
 from test_framework.mininode import (
     P2PInterface,
@@ -81,6 +82,7 @@ from test_framework.util import (
     hex_str_to_bytes,
     sync_blocks,
     sync_mempools,
+    assert_raises_rpc_error,
 )
 
 # The versionbit bit used to signal activation of SegWit
@@ -104,7 +106,7 @@ def get_p2pkh_script(pubkeyhash):
 def sign_p2pk_witness_input(script, tx_to, in_idx, hashtype, value, key):
     """Add signature for a P2PK witness program."""
     tx_hash = SegwitVersion1SignatureHash(script, tx_to, in_idx, hashtype, value)
-    signature = key.sign(tx_hash) + chr(hashtype).encode('latin-1')
+    signature = key.sign_ecdsa(tx_hash) + chr(hashtype).encode('latin-1')
     tx_to.wit.vtxinwit[in_idx].scriptWitness.stack = [signature, script]
     tx_to.rehash()
 
@@ -273,6 +275,7 @@ class SegWitTest(BitcoinTestFramework):
         self.test_non_standard_witness()
         self.test_upgrade_after_activation()
         self.test_witness_sigops()
+        self.test_superfluous_witness()
 
     # Individual tests
 
@@ -1483,10 +1486,9 @@ class SegWitTest(BitcoinTestFramework):
 
         # Segwit transactions using uncompressed pubkeys are not accepted
         # under default policy, but should still pass consensus.
-        key = CECKey()
-        key.set_secretbytes(b"9")
-        key.set_compressed(False)
-        pubkey = CPubKey(key.get_pubkey())
+        key = ECKey()
+        key.generate(False)
+        pubkey = key.get_pubkey().get_bytes()
         assert_equal(len(pubkey), 65)  # This should be an uncompressed pubkey
 
         utxo = self.utxo.pop(0)
@@ -1516,7 +1518,7 @@ class SegWitTest(BitcoinTestFramework):
         tx2.vout.append(CTxOut(tx.vout[0].nValue - 1000, script_wsh))
         script = get_p2pkh_script(pubkeyhash)
         sig_hash = SegwitVersion1SignatureHash(script, tx2, 0, SIGHASH_ALL, tx.vout[0].nValue)
-        signature = key.sign(sig_hash) + b'\x01'  # 0x1 is SIGHASH_ALL
+        signature = key.sign_ecdsa(sig_hash) + b'\x01'  # 0x1 is SIGHASH_ALL
         tx2.wit.vtxinwit.append(CTxInWitness())
         tx2.wit.vtxinwit[0].scriptWitness.stack = [signature, pubkey]
         tx2.rehash()
@@ -1570,7 +1572,7 @@ class SegWitTest(BitcoinTestFramework):
         tx5.vin.append(CTxIn(COutPoint(tx4.sha256, 0), b""))
         tx5.vout.append(CTxOut(tx4.vout[0].nValue - 1000, CScript([OP_TRUE])))
         (sig_hash, err) = SignatureHash(script_pubkey, tx5, 0, SIGHASH_ALL)
-        signature = key.sign(sig_hash) + b'\x01'  # 0x1 is SIGHASH_ALL
+        signature = key.sign_ecdsa(sig_hash) + b'\x01'  # 0x1 is SIGHASH_ALL
         tx5.vin[0].scriptSig = CScript([signature, pubkey])
         tx5.rehash()
         # Should pass policy and consensus.
@@ -1583,9 +1585,9 @@ class SegWitTest(BitcoinTestFramework):
     @subtest
     def test_signature_version_1(self):
 
-        key = CECKey()
-        key.set_secretbytes(b"9")
-        pubkey = CPubKey(key.get_pubkey())
+        key = ECKey()
+        key.generate()
+        pubkey = key.get_pubkey().get_bytes()
 
         witness_program = CScript([pubkey, CScriptOp(OP_CHECKSIG)])
         witness_hash = sha256(witness_program)
@@ -1720,7 +1722,7 @@ class SegWitTest(BitcoinTestFramework):
 
         script = get_p2pkh_script(pubkeyhash)
         sig_hash = SegwitVersion1SignatureHash(script, tx2, 0, SIGHASH_ALL, tx.vout[0].nValue)
-        signature = key.sign(sig_hash) + b'\x01'  # 0x1 is SIGHASH_ALL
+        signature = key.sign_ecdsa(sig_hash) + b'\x01'  # 0x1 is SIGHASH_ALL
 
         # Check that we can't have a scriptSig
         tx2.vin[0].scriptSig = CScript([signature, pubkey])
@@ -2039,5 +2041,51 @@ class SegWitTest(BitcoinTestFramework):
 
         # TODO: test p2sh sigop counting
 
+    def test_superfluous_witness(self):
+        # Serialization of tx that puts witness flag to 3 always
+        def serialize_with_bogus_witness(tx):
+            flags = 3
+            r = b""
+            r += struct.pack("<i", tx.nVersion)
+            if flags:
+                dummy = []
+                r += ser_vector(dummy)
+                r += struct.pack("<B", flags)
+            r += ser_vector(tx.vin)
+            r += ser_vector(tx.vout)
+            if flags & 1:
+                if (len(tx.wit.vtxinwit) != len(tx.vin)):
+                    # vtxinwit must have the same length as vin
+                    tx.wit.vtxinwit = tx.wit.vtxinwit[:len(tx.vin)]
+                    for i in range(len(tx.wit.vtxinwit), len(tx.vin)):
+                        tx.wit.vtxinwit.append(CTxInWitness())
+                r += tx.wit.serialize()
+            r += struct.pack("<I", tx.nLockTime)
+            return r
+
+        class msg_bogus_tx(msg_tx):
+            def serialize(self):
+                return serialize_with_bogus_witness(self.tx)
+
+        self.nodes[0].sendtoaddress(self.nodes[0].getnewaddress(address_type='bech32'), 5)
+        self.nodes[0].generate(1)
+        unspent = next(u for u in self.nodes[0].listunspent() if u['spendable'] and u['address'].startswith('bcrt'))
+
+        raw = self.nodes[0].createrawtransaction([{"txid": unspent['txid'], "vout": unspent['vout']}], {self.nodes[0].getnewaddress(): 1})
+        tx = FromHex(CTransaction(), raw)
+        assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].decoderawtransaction, serialize_with_bogus_witness(tx).hex())
+        with self.nodes[0].assert_debug_log(['Superfluous witness record']):
+            self.nodes[0].p2p.send_message(msg_bogus_tx(tx))
+            self.nodes[0].p2p.sync_with_ping()
+        raw = self.nodes[0].signrawtransactionwithwallet(raw)
+        assert raw['complete']
+        raw = raw['hex']
+        tx = FromHex(CTransaction(), raw)
+        assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].decoderawtransaction, serialize_with_bogus_witness(tx).hex())
+        with self.nodes[0].assert_debug_log(['Unknown transaction optional data']):
+            self.nodes[0].p2p.send_message(msg_bogus_tx(tx))
+            self.nodes[0].p2p.sync_with_ping()
+
+
 if __name__ == '__main__':
     SegWitTest().main()
diff --git a/test/functional/rpc_createmultisig.py b/test/functional/rpc_createmultisig.py
index 3cc35a7b9a4..1f717f59d0d 100755
--- a/test/functional/rpc_createmultisig.py
+++ b/test/functional/rpc_createmultisig.py
@@ -1,11 +1,19 @@
 #!/usr/bin/env python3
-# Copyright (c) 2015-2018 The Bitcoin Core developers
+# Copyright (c) 2015-2019 The Bitcoin Core developers
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
-"""Test transaction signing using the signrawtransaction* RPCs."""
+"""Test multisig RPCs"""
 
 from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import (
+    assert_raises_rpc_error,
+    assert_equal,
+)
+from test_framework.key import ECPubKey
+
+import binascii
 import decimal
+import itertools
 
 class RpcCreateMultiSigTest(BitcoinTestFramework):
     def set_test_params(self):
@@ -17,29 +25,64 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
 
     def get_keys(self):
         node0, node1, node2 = self.nodes
-        self.add = [node1.getnewaddress() for _ in range(self.nkeys)]
-        self.pub = [node1.getaddressinfo(a)["pubkey"] for a in self.add]
-        self.priv = [node1.dumpprivkey(a) for a in self.add]
+        add = [node1.getnewaddress() for _ in range(self.nkeys)]
+        self.pub = [node1.getaddressinfo(a)["pubkey"] for a in add]
+        self.priv = [node1.dumpprivkey(a) for a in add]
         self.final = node2.getnewaddress()
 
     def run_test(self):
-        node0,node1,node2 = self.nodes
+        node0, node1, node2 = self.nodes
 
-        # 50 BTC each, rest will be 25 BTC each
+        self.check_addmultisigaddress_errors()
+
+        self.log.info('Generating blocks ...')
         node0.generate(149)
         self.sync_all()
 
         self.moved = 0
-        for self.nkeys in [3,5]:
-            for self.nsigs in [2,3]:
+        for self.nkeys in [3, 5]:
+            for self.nsigs in [2, 3]:
                 for self.output_type in ["bech32", "p2sh-segwit", "legacy"]:
                     self.get_keys()
                     self.do_multisig()
 
         self.checkbalances()
 
+        # Test mixed compressed and uncompressed pubkeys
+        self.log.info('Mixed compressed and uncompressed multisigs are not allowed')
+        pk0 = node0.getaddressinfo(node0.getnewaddress())['pubkey']
+        pk1 = node1.getaddressinfo(node1.getnewaddress())['pubkey']
+        pk2 = node2.getaddressinfo(node2.getnewaddress())['pubkey']
+
+        # decompress pk2
+        pk_obj = ECPubKey()
+        pk_obj.set(binascii.unhexlify(pk2))
+        pk_obj.compressed = False
+        pk2 = binascii.hexlify(pk_obj.get_bytes()).decode()
+
+        # Check all permutations of keys because order matters apparently
+        for keys in itertools.permutations([pk0, pk1, pk2]):
+            # Results should be the same as this legacy one
+            legacy_addr = node0.createmultisig(2, keys, 'legacy')['address']
+            assert_equal(legacy_addr, node0.addmultisigaddress(2, keys, '', 'legacy')['address'])
+
+            # Generate addresses with the segwit types. These should all make legacy addresses
+            assert_equal(legacy_addr, node0.createmultisig(2, keys, 'bech32')['address'])
+            assert_equal(legacy_addr, node0.createmultisig(2, keys, 'p2sh-segwit')['address'])
+            assert_equal(legacy_addr, node0.addmultisigaddress(2, keys, '', 'bech32')['address'])
+            assert_equal(legacy_addr, node0.addmultisigaddress(2, keys, '', 'p2sh-segwit')['address'])
+
+    def check_addmultisigaddress_errors(self):
+        self.log.info('Check that addmultisigaddress fails when the private keys are missing')
+        addresses = [self.nodes[1].getnewaddress(address_type='legacy') for _ in range(2)]
+        assert_raises_rpc_error(-5, 'no full public key for address', lambda: self.nodes[0].addmultisigaddress(nrequired=1, keys=addresses))
+        for a in addresses:
+            # Importing all addresses should not change the result
+            self.nodes[0].importaddress(a)
+        assert_raises_rpc_error(-5, 'no full public key for address', lambda: self.nodes[0].addmultisigaddress(nrequired=1, keys=addresses))
+
     def checkbalances(self):
-        node0,node1,node2 = self.nodes
+        node0, node1, node2 = self.nodes
         node0.generate(100)
         self.sync_all()
 
@@ -49,13 +92,13 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
 
         height = node0.getblockchaininfo()["blocks"]
         assert 150 < height < 350
-        total = 149*50 + (height-149-100)*25
+        total = 149 * 50 + (height - 149 - 100) * 25
         assert bal1 == 0
         assert bal2 == self.moved
-        assert bal0+bal1+bal2 == total
+        assert bal0 + bal1 + bal2 == total
 
     def do_multisig(self):
-        node0,node1,node2 = self.nodes
+        node0, node1, node2 = self.nodes
 
         msig = node2.createmultisig(self.nsigs, self.pub, self.output_type)
         madd = msig["address"]
@@ -74,7 +117,7 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         txid = node0.sendtoaddress(madd, 40)
 
         tx = node0.getrawtransaction(txid, True)
-        vout = [v["n"] for v in tx["vout"] if madd in v["scriptPubKey"].get("addresses",[])]
+        vout = [v["n"] for v in tx["vout"] if madd in v["scriptPubKey"].get("addresses", [])]
         assert len(vout) == 1
         vout = vout[0]
         scriptPubKey = tx["vout"][vout]["scriptPubKey"]["hex"]
@@ -86,7 +129,7 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         outval = value - decimal.Decimal("0.00001000")
         rawtx = node2.createrawtransaction([{"txid": txid, "vout": vout}], [{self.final: outval}])
 
-        rawtx2 = node2.signrawtransactionwithkey(rawtx, self.priv[0:self.nsigs-1], prevtxs)
+        rawtx2 = node2.signrawtransactionwithkey(rawtx, self.priv[0:self.nsigs - 1], prevtxs)
         rawtx3 = node2.signrawtransactionwithkey(rawtx2["hex"], [self.priv[-1]], prevtxs)
 
         self.moved += outval
@@ -97,5 +140,6 @@ class RpcCreateMultiSigTest(BitcoinTestFramework):
         txinfo = node0.getrawtransaction(tx, True, blk)
         self.log.info("n/m=%d/%d %s size=%d vsize=%d weight=%d" % (self.nsigs, self.nkeys, self.output_type, txinfo["size"], txinfo["vsize"], txinfo["weight"]))
 
+
 if __name__ == '__main__':
     RpcCreateMultiSigTest().main()
diff --git a/test/functional/rpc_psbt.py b/test/functional/rpc_psbt.py
index 53f606f2ec0..6c0aec92288 100755
--- a/test/functional/rpc_psbt.py
+++ b/test/functional/rpc_psbt.py
@@ -144,10 +144,12 @@ class PSBTTest(BitcoinTestFramework):
         new_psbt = self.nodes[0].converttopsbt(rawtx['hex'])
         self.nodes[0].decodepsbt(new_psbt)
 
-        # Make sure that a psbt with signatures cannot be converted
+        # Make sure that a non-psbt with signatures cannot be converted
+        # Error could be either "TX decode failed" (segwit inputs causes parsing to fail) or "Inputs must not have scriptSigs and scriptWitnesses"
+        # We must set iswitness=True because the serialized transaction has inputs and is therefore a witness transaction
         signedtx = self.nodes[0].signrawtransactionwithwallet(rawtx['hex'])
-        assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].converttopsbt, signedtx['hex'])
-        assert_raises_rpc_error(-22, "TX decode failed", self.nodes[0].converttopsbt, signedtx['hex'], False)
+        assert_raises_rpc_error(-22, "", self.nodes[0].converttopsbt, hexstring=signedtx['hex'], iswitness=True)
+        assert_raises_rpc_error(-22, "", self.nodes[0].converttopsbt, hexstring=signedtx['hex'], permitsigdata=False, iswitness=True)
         # Unless we allow it to convert and strip signatures
         self.nodes[0].converttopsbt(signedtx['hex'], True)
 
diff --git a/test/functional/test_framework/key.py b/test/functional/test_framework/key.py
index 1b3e510dc44..912c0ca978e 100644
--- a/test/functional/test_framework/key.py
+++ b/test/functional/test_framework/key.py
@@ -1,226 +1,386 @@
-# Copyright (c) 2011 Sam Rushing
-"""ECC secp256k1 OpenSSL wrapper.
+# Copyright (c) 2019 Pieter Wuille
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test-only secp256k1 elliptic curve implementation
 
-WARNING: This module does not mlock() secrets; your private keys may end up on
-disk in swap! Use with caution!
+WARNING: This code is slow, uses bad randomness, does not properly protect
+keys, and is trivially vulnerable to side channel attacks. Do not use for
+anything but tests."""
+import random
 
-This file is modified from python-bitcoinlib.
-"""
+def modinv(a, n):
+    """Compute the modular inverse of a modulo n
 
-import ctypes
-import ctypes.util
-import hashlib
+    See https://en.wikipedia.org/wiki/Extended_Euclidean_algorithm#Modular_integers.
+    """
+    t1, t2 = 0, 1
+    r1, r2 = n, a
+    while r2 != 0:
+        q = r1 // r2
+        t1, t2 = t2, t1 - q * t2
+        r1, r2 = r2, r1 - q * r2
+    if r1 > 1:
+        return None
+    if t1 < 0:
+        t1 += n
+    return t1
 
-ssl = ctypes.cdll.LoadLibrary(ctypes.util.find_library ('ssl') or 'libeay32')
+def jacobi_symbol(n, k):
+    """Compute the Jacobi symbol of n modulo k
 
-ssl.BN_new.restype = ctypes.c_void_p
-ssl.BN_new.argtypes = []
+    See http://en.wikipedia.org/wiki/Jacobi_symbol
 
-ssl.BN_bin2bn.restype = ctypes.c_void_p
-ssl.BN_bin2bn.argtypes = [ctypes.c_char_p, ctypes.c_int, ctypes.c_void_p]
+    For our application k is always prime, so this is the same as the Legendre symbol."""
+    assert k > 0 and k & 1, "jacobi symbol is only defined for positive odd k"
+    n %= k
+    t = 0
+    while n != 0:
+        while n & 1 == 0:
+            n >>= 1
+            r = k & 7
+            t ^= (r == 3 or r == 5)
+        n, k = k, n
+        t ^= (n & k & 3 == 3)
+        n = n % k
+    if k == 1:
+        return -1 if t else 1
+    return 0
 
-ssl.BN_CTX_free.restype = None
-ssl.BN_CTX_free.argtypes = [ctypes.c_void_p]
+def modsqrt(a, p):
+    """Compute the square root of a modulo p when p % 4 = 3.
 
-ssl.BN_CTX_new.restype = ctypes.c_void_p
-ssl.BN_CTX_new.argtypes = []
+    The Tonelli-Shanks algorithm can be used. See https://en.wikipedia.org/wiki/Tonelli-Shanks_algorithm
 
-ssl.ECDH_compute_key.restype = ctypes.c_int
-ssl.ECDH_compute_key.argtypes = [ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p]
+    Limiting this function to only work for p % 4 = 3 means we don't need to
+    iterate through the loop. The highest n such that p - 1 = 2^n Q with Q odd
+    is n = 1. Therefore Q = (p-1)/2 and sqrt = a^((Q+1)/2) = a^((p+1)/4)
 
-ssl.ECDSA_sign.restype = ctypes.c_int
-ssl.ECDSA_sign.argtypes = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
+    secp256k1's is defined over field of size 2**256 - 2**32 - 977, which is 3 mod 4.
+    """
+    if p % 4 != 3:
+        raise NotImplementedError("modsqrt only implemented for p % 4 = 3")
+    sqrt = pow(a, (p + 1)//4, p)
+    if pow(sqrt, 2, p) == a % p:
+        return sqrt
+    return None
 
-ssl.ECDSA_verify.restype = ctypes.c_int
-ssl.ECDSA_verify.argtypes = [ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p]
+class EllipticCurve:
+    def __init__(self, p, a, b):
+        """Initialize elliptic curve y^2 = x^3 + a*x + b over GF(p)."""
+        self.p = p
+        self.a = a % p
+        self.b = b % p
 
-ssl.EC_KEY_free.restype = None
-ssl.EC_KEY_free.argtypes = [ctypes.c_void_p]
+    def affine(self, p1):
+        """Convert a Jacobian point tuple p1 to affine form, or None if at infinity.
 
-ssl.EC_KEY_new_by_curve_name.restype = ctypes.c_void_p
-ssl.EC_KEY_new_by_curve_name.argtypes = [ctypes.c_int]
+        An affine point is represented as the Jacobian (x, y, 1)"""
+        x1, y1, z1 = p1
+        if z1 == 0:
+            return None
+        inv = modinv(z1, self.p)
+        inv_2 = (inv**2) % self.p
+        inv_3 = (inv_2 * inv) % self.p
+        return ((inv_2 * x1) % self.p, (inv_3 * y1) % self.p, 1)
 
-ssl.EC_KEY_get0_group.restype = ctypes.c_void_p
-ssl.EC_KEY_get0_group.argtypes = [ctypes.c_void_p]
+    def negate(self, p1):
+        """Negate a Jacobian point tuple p1."""
+        x1, y1, z1 = p1
+        return (x1, (self.p - y1) % self.p, z1)
 
-ssl.EC_KEY_get0_public_key.restype = ctypes.c_void_p
-ssl.EC_KEY_get0_public_key.argtypes = [ctypes.c_void_p]
+    def on_curve(self, p1):
+        """Determine whether a Jacobian tuple p is on the curve (and not infinity)"""
+        x1, y1, z1 = p1
+        z2 = pow(z1, 2, self.p)
+        z4 = pow(z2, 2, self.p)
+        return z1 != 0 and (pow(x1, 3, self.p) + self.a * x1 * z4 + self.b * z2 * z4 - pow(y1, 2, self.p)) % self.p == 0
 
-ssl.EC_KEY_set_private_key.restype = ctypes.c_int
-ssl.EC_KEY_set_private_key.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
+    def is_x_coord(self, x):
+        """Test whether x is a valid X coordinate on the curve."""
+        x_3 = pow(x, 3, self.p)
+        return jacobi_symbol(x_3 + self.a * x + self.b, self.p) != -1
 
-ssl.EC_KEY_set_conv_form.restype = None
-ssl.EC_KEY_set_conv_form.argtypes = [ctypes.c_void_p, ctypes.c_int]
+    def lift_x(self, x):
+        """Given an X coordinate on the curve, return a corresponding affine point."""
+        x_3 = pow(x, 3, self.p)
+        v = x_3 + self.a * x + self.b
+        y = modsqrt(v, self.p)
+        if y is None:
+            return None
+        return (x, y, 1)
 
-ssl.EC_KEY_set_public_key.restype = ctypes.c_int
-ssl.EC_KEY_set_public_key.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
+    def double(self, p1):
+        """Double a Jacobian tuple p1
 
-ssl.i2o_ECPublicKey.restype = ctypes.c_void_p
-ssl.i2o_ECPublicKey.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
+        See https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates - Point Doubling"""
+        x1, y1, z1 = p1
+        if z1 == 0:
+            return (0, 1, 0)
+        y1_2 = (y1**2) % self.p
+        y1_4 = (y1_2**2) % self.p
+        x1_2 = (x1**2) % self.p
+        s = (4*x1*y1_2) % self.p
+        m = 3*x1_2
+        if self.a:
+            m += self.a * pow(z1, 4, self.p)
+        m = m % self.p
+        x2 = (m**2 - 2*s) % self.p
+        y2 = (m*(s - x2) - 8*y1_4) % self.p
+        z2 = (2*y1*z1) % self.p
+        return (x2, y2, z2)
 
-ssl.EC_POINT_new.restype = ctypes.c_void_p
-ssl.EC_POINT_new.argtypes = [ctypes.c_void_p]
+    def add_mixed(self, p1, p2):
+        """Add a Jacobian tuple p1 and an affine tuple p2
 
-ssl.EC_POINT_free.restype = None
-ssl.EC_POINT_free.argtypes = [ctypes.c_void_p]
+        See https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates - Point Addition (with affine point)"""
+        x1, y1, z1 = p1
+        x2, y2, z2 = p2
+        assert(z2 == 1)
+        # Adding to the point at infinity is a no-op
+        if z1 == 0:
+            return p2
+        z1_2 = (z1**2) % self.p
+        z1_3 = (z1_2 * z1) % self.p
+        u2 = (x2 * z1_2) % self.p
+        s2 = (y2 * z1_3) % self.p
+        if x1 == u2:
+            if (y1 != s2):
+                # p1 and p2 are inverses. Return the point at infinity.
+                return (0, 1, 0)
+            # p1 == p2. The formulas below fail when the two points are equal.
+            return self.double(p1)
+        h = u2 - x1
+        r = s2 - y1
+        h_2 = (h**2) % self.p
+        h_3 = (h_2 * h) % self.p
+        u1_h_2 = (x1 * h_2) % self.p
+        x3 = (r**2 - h_3 - 2*u1_h_2) % self.p
+        y3 = (r*(u1_h_2 - x3) - y1*h_3) % self.p
+        z3 = (h*z1) % self.p
+        return (x3, y3, z3)
 
-ssl.EC_POINT_mul.restype = ctypes.c_int
-ssl.EC_POINT_mul.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
+    def add(self, p1, p2):
+        """Add two Jacobian tuples p1 and p2
 
-# this specifies the curve used with ECDSA.
-NID_secp256k1 = 714 # from openssl/obj_mac.h
+        See https://en.wikibooks.org/wiki/Cryptography/Prime_Curve/Jacobian_Coordinates - Point Addition"""
+        x1, y1, z1 = p1
+        x2, y2, z2 = p2
+        # Adding the point at infinity is a no-op
+        if z1 == 0:
+            return p2
+        if z2 == 0:
+            return p1
+        # Adding an Affine to a Jacobian is more efficient since we save field multiplications and squarings when z = 1
+        if z1 == 1:
+            return self.add_mixed(p2, p1)
+        if z2 == 1:
+            return self.add_mixed(p1, p2)
+        z1_2 = (z1**2) % self.p
+        z1_3 = (z1_2 * z1) % self.p
+        z2_2 = (z2**2) % self.p
+        z2_3 = (z2_2 * z2) % self.p
+        u1 = (x1 * z2_2) % self.p
+        u2 = (x2 * z1_2) % self.p
+        s1 = (y1 * z2_3) % self.p
+        s2 = (y2 * z1_3) % self.p
+        if u1 == u2:
+            if (s1 != s2):
+                # p1 and p2 are inverses. Return the point at infinity.
+                return (0, 1, 0)
+            # p1 == p2. The formulas below fail when the two points are equal.
+            return self.double(p1)
+        h = u2 - u1
+        r = s2 - s1
+        h_2 = (h**2) % self.p
+        h_3 = (h_2 * h) % self.p
+        u1_h_2 = (u1 * h_2) % self.p
+        x3 = (r**2 - h_3 - 2*u1_h_2) % self.p
+        y3 = (r*(u1_h_2 - x3) - s1*h_3) % self.p
+        z3 = (h*z1*z2) % self.p
+        return (x3, y3, z3)
 
+    def mul(self, ps):
+        """Compute a (multi) point multiplication
+
+        ps is a list of (Jacobian tuple, scalar) pairs.
+        """
+        r = (0, 1, 0)
+        for i in range(255, -1, -1):
+            r = self.double(r)
+            for (p, n) in ps:
+                if ((n >> i) & 1):
+                    r = self.add(r, p)
+        return r
+
+SECP256K1 = EllipticCurve(2**256 - 2**32 - 977, 0, 7)
+SECP256K1_G = (0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798, 0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8, 1)
 SECP256K1_ORDER = 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141
 SECP256K1_ORDER_HALF = SECP256K1_ORDER // 2
 
-# Thx to Sam Devlin for the ctypes magic 64-bit fix.
-def _check_result(val, func, args):
-    if val == 0:
-        raise ValueError
-    else:
-        return ctypes.c_void_p (val)
-
-ssl.EC_KEY_new_by_curve_name.restype = ctypes.c_void_p
-ssl.EC_KEY_new_by_curve_name.errcheck = _check_result
-
-class CECKey():
-    """Wrapper around OpenSSL's EC_KEY"""
-
-    POINT_CONVERSION_COMPRESSED = 2
-    POINT_CONVERSION_UNCOMPRESSED = 4
+class ECPubKey():
+    """A secp256k1 public key"""
 
     def __init__(self):
-        self.k = ssl.EC_KEY_new_by_curve_name(NID_secp256k1)
+        """Construct an uninitialized public key"""
+        self.valid = False
 
-    def __del__(self):
-        if ssl:
-            ssl.EC_KEY_free(self.k)
-        self.k = None
-
-    def set_secretbytes(self, secret):
-        priv_key = ssl.BN_bin2bn(secret, 32, ssl.BN_new())
-        group = ssl.EC_KEY_get0_group(self.k)
-        pub_key = ssl.EC_POINT_new(group)
-        ctx = ssl.BN_CTX_new()
-        if not ssl.EC_POINT_mul(group, pub_key, priv_key, None, None, ctx):
-            raise ValueError("Could not derive public key from the supplied secret.")
-        ssl.EC_POINT_mul(group, pub_key, priv_key, None, None, ctx)
-        ssl.EC_KEY_set_private_key(self.k, priv_key)
-        ssl.EC_KEY_set_public_key(self.k, pub_key)
-        ssl.EC_POINT_free(pub_key)
-        ssl.BN_CTX_free(ctx)
-        return self.k
-
-    def set_privkey(self, key):
-        self.mb = ctypes.create_string_buffer(key)
-        return ssl.d2i_ECPrivateKey(ctypes.byref(self.k), ctypes.byref(ctypes.pointer(self.mb)), len(key))
-
-    def set_pubkey(self, key):
-        self.mb = ctypes.create_string_buffer(key)
-        return ssl.o2i_ECPublicKey(ctypes.byref(self.k), ctypes.byref(ctypes.pointer(self.mb)), len(key))
-
-    def get_privkey(self):
-        size = ssl.i2d_ECPrivateKey(self.k, 0)
-        mb_pri = ctypes.create_string_buffer(size)
-        ssl.i2d_ECPrivateKey(self.k, ctypes.byref(ctypes.pointer(mb_pri)))
-        return mb_pri.raw
-
-    def get_pubkey(self):
-        size = ssl.i2o_ECPublicKey(self.k, 0)
-        mb = ctypes.create_string_buffer(size)
-        ssl.i2o_ECPublicKey(self.k, ctypes.byref(ctypes.pointer(mb)))
-        return mb.raw
-
-    def get_raw_ecdh_key(self, other_pubkey):
-        ecdh_keybuffer = ctypes.create_string_buffer(32)
-        r = ssl.ECDH_compute_key(ctypes.pointer(ecdh_keybuffer), 32,
-                                 ssl.EC_KEY_get0_public_key(other_pubkey.k),
-                                 self.k, 0)
-        if r != 32:
-            raise Exception('CKey.get_ecdh_key(): ECDH_compute_key() failed')
-        return ecdh_keybuffer.raw
-
-    def get_ecdh_key(self, other_pubkey, kdf=lambda k: hashlib.sha256(k).digest()):
-        # FIXME: be warned it's not clear what the kdf should be as a default
-        r = self.get_raw_ecdh_key(other_pubkey)
-        return kdf(r)
-
-    def sign(self, hash, low_s = True):
-        # FIXME: need unit tests for below cases
-        if not isinstance(hash, bytes):
-            raise TypeError('Hash must be bytes instance; got %r' % hash.__class__)
-        if len(hash) != 32:
-            raise ValueError('Hash must be exactly 32 bytes long')
-
-        sig_size0 = ctypes.c_uint32()
-        sig_size0.value = ssl.ECDSA_size(self.k)
-        mb_sig = ctypes.create_string_buffer(sig_size0.value)
-        result = ssl.ECDSA_sign(0, hash, len(hash), mb_sig, ctypes.byref(sig_size0), self.k)
-        assert 1 == result
-        assert mb_sig.raw[0] == 0x30
-        assert mb_sig.raw[1] == sig_size0.value - 2
-        total_size = mb_sig.raw[1]
-        assert mb_sig.raw[2] == 2
-        r_size = mb_sig.raw[3]
-        assert mb_sig.raw[4 + r_size] == 2
-        s_size = mb_sig.raw[5 + r_size]
-        s_value = int.from_bytes(mb_sig.raw[6+r_size:6+r_size+s_size], byteorder='big')
-        if (not low_s) or s_value <= SECP256K1_ORDER_HALF:
-            return mb_sig.raw[:sig_size0.value]
+    def set(self, data):
+        """Construct a public key from a serialization in compressed or uncompressed format"""
+        if (len(data) == 65 and data[0] == 0x04):
+            p = (int.from_bytes(data[1:33], 'big'), int.from_bytes(data[33:65], 'big'), 1)
+            self.valid = SECP256K1.on_curve(p)
+            if self.valid:
+                self.p = p
+                self.compressed = False
+        elif (len(data) == 33 and (data[0] == 0x02 or data[0] == 0x03)):
+            x = int.from_bytes(data[1:33], 'big')
+            if SECP256K1.is_x_coord(x):
+                p = SECP256K1.lift_x(x)
+                # if the oddness of the y co-ord isn't correct, find the other
+                # valid y
+                if (p[1] & 1) != (data[0] & 1):
+                    p = SECP256K1.negate(p)
+                self.p = p
+                self.valid = True
+                self.compressed = True
+            else:
+                self.valid = False
         else:
-            low_s_value = SECP256K1_ORDER - s_value
-            low_s_bytes = (low_s_value).to_bytes(33, byteorder='big')
-            while len(low_s_bytes) > 1 and low_s_bytes[0] == 0 and low_s_bytes[1] < 0x80:
-                low_s_bytes = low_s_bytes[1:]
-            new_s_size = len(low_s_bytes)
-            new_total_size_byte = (total_size + new_s_size - s_size).to_bytes(1,byteorder='big')
-            new_s_size_byte = (new_s_size).to_bytes(1,byteorder='big')
-            return b'\x30' + new_total_size_byte + mb_sig.raw[2:5+r_size] + new_s_size_byte + low_s_bytes
-
-    def verify(self, hash, sig):
-        """Verify a DER signature"""
-        return ssl.ECDSA_verify(0, hash, len(hash), sig, len(sig), self.k) == 1
-
-    def set_compressed(self, compressed):
-        if compressed:
-            form = self.POINT_CONVERSION_COMPRESSED
-        else:
-            form = self.POINT_CONVERSION_UNCOMPRESSED
-        ssl.EC_KEY_set_conv_form(self.k, form)
-
-
-class CPubKey(bytes):
-    """An encapsulated public key
-
-    Attributes:
-
-    is_valid      - Corresponds to CPubKey.IsValid()
-    is_fullyvalid - Corresponds to CPubKey.IsFullyValid()
-    is_compressed - Corresponds to CPubKey.IsCompressed()
-    """
-
-    def __new__(cls, buf, _cec_key=None):
-        self = super(CPubKey, cls).__new__(cls, buf)
-        if _cec_key is None:
-            _cec_key = CECKey()
-        self._cec_key = _cec_key
-        self.is_fullyvalid = _cec_key.set_pubkey(self) != 0
-        return self
-
-    @property
-    def is_valid(self):
-        return len(self) > 0
+            self.valid = False
 
     @property
     def is_compressed(self):
-        return len(self) == 33
+        return self.compressed
 
-    def verify(self, hash, sig):
-        return self._cec_key.verify(hash, sig)
+    @property
+    def is_valid(self):
+        return self.valid
 
-    def __str__(self):
-        return repr(self)
+    def get_bytes(self):
+        assert(self.valid)
+        p = SECP256K1.affine(self.p)
+        if p is None:
+            return None
+        if self.compressed:
+            return bytes([0x02 + (p[1] & 1)]) + p[0].to_bytes(32, 'big')
+        else:
+            return bytes([0x04]) + p[0].to_bytes(32, 'big') + p[1].to_bytes(32, 'big')
 
-    def __repr__(self):
-        return '%s(%s)' % (self.__class__.__name__, super(CPubKey, self).__repr__())
+    def verify_ecdsa(self, sig, msg, low_s=True):
+        """Verify a strictly DER-encoded ECDSA signature against this pubkey.
 
+        See https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm for the
+        ECDSA verifier algorithm"""
+        assert(self.valid)
+
+        # Extract r and s from the DER formatted signature. Return false for
+        # any DER encoding errors.
+        if (sig[1] + 2 != len(sig)):
+            return False
+        if (len(sig) < 4):
+            return False
+        if (sig[0] != 0x30):
+            return False
+        if (sig[2] != 0x02):
+            return False
+        rlen = sig[3]
+        if (len(sig) < 6 + rlen):
+            return False
+        if rlen < 1 or rlen > 33:
+            return False
+        if sig[4] >= 0x80:
+            return False
+        if (rlen > 1 and (sig[4] == 0) and not (sig[5] & 0x80)):
+            return False
+        r = int.from_bytes(sig[4:4+rlen], 'big')
+        if (sig[4+rlen] != 0x02):
+            return False
+        slen = sig[5+rlen]
+        if slen < 1 or slen > 33:
+            return False
+        if (len(sig) != 6 + rlen + slen):
+            return False
+        if sig[6+rlen] >= 0x80:
+            return False
+        if (slen > 1 and (sig[6+rlen] == 0) and not (sig[7+rlen] & 0x80)):
+            return False
+        s = int.from_bytes(sig[6+rlen:6+rlen+slen], 'big')
+
+        # Verify that r and s are within the group order
+        if r < 1 or s < 1 or r >= SECP256K1_ORDER or s >= SECP256K1_ORDER:
+            return False
+        if low_s and s >= SECP256K1_ORDER_HALF:
+            return False
+        z = int.from_bytes(msg, 'big')
+
+        # Run verifier algorithm on r, s
+        w = modinv(s, SECP256K1_ORDER)
+        u1 = z*w % SECP256K1_ORDER
+        u2 = r*w % SECP256K1_ORDER
+        R = SECP256K1.affine(SECP256K1.mul([(SECP256K1_G, u1), (self.p, u2)]))
+        if R is None or R[0] != r:
+            return False
+        return True
+
+class ECKey():
+    """A secp256k1 private key"""
+
+    def __init__(self):
+        self.valid = False
+
+    def set(self, secret, compressed):
+        """Construct a private key object with given 32-byte secret and compressed flag."""
+        assert(len(secret) == 32)
+        secret = int.from_bytes(secret, 'big')
+        self.valid = (secret > 0 and secret < SECP256K1_ORDER)
+        if self.valid:
+            self.secret = secret
+            self.compressed = compressed
+
+    def generate(self, compressed=True):
+        """Generate a random private key (compressed or uncompressed)."""
+        self.set(random.randrange(1, SECP256K1_ORDER).to_bytes(32, 'big'), compressed)
+
+    def get_bytes(self):
+        """Retrieve the 32-byte representation of this key."""
+        assert(self.valid)
+        return self.secret.to_bytes(32, 'big')
+
+    @property
+    def is_valid(self):
+        return self.valid
+
+    @property
+    def is_compressed(self):
+        return self.compressed
+
+    def get_pubkey(self):
+        """Compute an ECPubKey object for this secret key."""
+        assert(self.valid)
+        ret = ECPubKey()
+        p = SECP256K1.mul([(SECP256K1_G, self.secret)])
+        ret.p = p
+        ret.valid = True
+        ret.compressed = self.compressed
+        return ret
+
+    def sign_ecdsa(self, msg, low_s=True):
+        """Construct a DER-encoded ECDSA signature with this key.
+
+        See https://en.wikipedia.org/wiki/Elliptic_Curve_Digital_Signature_Algorithm for the
+        ECDSA signer algorithm."""
+        assert(self.valid)
+        z = int.from_bytes(msg, 'big')
+        # Note: no RFC6979, but a simple random nonce (some tests rely on distinct transactions for the same operation)
+        k = random.randrange(1, SECP256K1_ORDER)
+        R = SECP256K1.affine(SECP256K1.mul([(SECP256K1_G, k)]))
+        r = R[0] % SECP256K1_ORDER
+        s = (modinv(k, SECP256K1_ORDER) * (z + self.secret * r)) % SECP256K1_ORDER
+        if low_s and s > SECP256K1_ORDER_HALF:
+            s = SECP256K1_ORDER - s
+        # Represent in DER format. The byte representations of r and s have
+        # length rounded up (255 bits becomes 32 bytes and 256 bits becomes 33
+        # bytes).
+        rb = r.to_bytes((r.bit_length() + 8) // 8, 'big')
+        sb = s.to_bytes((s.bit_length() + 8) // 8, 'big')
+        return b'\x30' + bytes([4 + len(rb) + len(sb), 2, len(rb)]) + rb + bytes([2, len(sb)]) + sb
diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index ac7cc068bdb..6afdd501762 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -364,6 +364,14 @@ class P2PInterface(P2PConnection):
 
     # Message receiving helper methods
 
+    def wait_for_tx(self, txid, timeout=60):
+        def test_function():
+            if not self.last_message.get('tx'):
+                return False
+            return self.last_message['tx'].tx.rehash() == txid
+
+        wait_until(test_function, timeout=timeout, lock=mininode_lock)
+
     def wait_for_block(self, blockhash, timeout=60):
         test_function = lambda: self.last_message.get("block") and self.last_message["block"].block.rehash() == blockhash
         wait_until(test_function, timeout=timeout, lock=mininode_lock)
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index fef99824127..87e2dbaf163 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -219,7 +219,7 @@ def wait_until(predicate, *, attempts=float('inf'), timeout=float('inf'), lock=N
         time.sleep(0.05)
 
     # Print the cause of the timeout
-    predicate_source = inspect.getsourcelines(predicate)
+    predicate_source = "''''\n" + inspect.getsource(predicate) + "'''"
     logger.error("wait_until() failed. Predicate: {}".format(predicate_source))
     if attempt >= attempts:
         raise AssertionError("Predicate {} not true after {} attempts".format(predicate_source, attempts))
diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
index bb9ac58e46c..06d3552195f 100755
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -134,6 +134,7 @@ BASE_SCRIPTS = [
     'rpc_net.py',
     'wallet_keypool.py',
     'p2p_mempool.py',
+    'p2p_blocksonly.py',
     'mining_prioritisetransaction.py',
     'p2p_invalid_locator.py',
     'p2p_invalid_block.py',
diff --git a/test/lint/lint-format-strings.sh b/test/lint/lint-format-strings.sh
index c994ae3f4de..cb630c78ade 100755
--- a/test/lint/lint-format-strings.sh
+++ b/test/lint/lint-format-strings.sh
@@ -13,6 +13,7 @@ export LC_ALL=C
 FUNCTION_NAMES_AND_NUMBER_OF_LEADING_ARGUMENTS=(
     "FatalError,0"
     "fprintf,1"
+    "tfm::format,1" # Assuming tfm::::format(std::ostream&, ...
     "LogConnectFailure,1"
     "LogPrint,1"
     "LogPrintf,0"
diff --git a/test/lint/lint-locale-dependence.sh b/test/lint/lint-locale-dependence.sh
index 2b6c78c2c84..9a1aa766f79 100755
--- a/test/lint/lint-locale-dependence.sh
+++ b/test/lint/lint-locale-dependence.sh
@@ -8,7 +8,6 @@ KNOWN_VIOLATIONS=(
     "src/dbwrapper.cpp:.*vsnprintf"
     "src/httprpc.cpp.*trim"
     "src/init.cpp:.*atoi"
-    "src/init.cpp:.*fprintf"
     "src/qt/rpcconsole.cpp:.*atoi"
     "src/rest.cpp:.*strtol"
     "src/test/dbwrapper_tests.cpp:.*snprintf"
@@ -85,7 +84,7 @@ LOCALE_DEPENDENT_FUNCTIONS=(
     mbtowc       # LC_CTYPE
     mktime
     normalize    # boost::locale::normalize
-#   printf       # LC_NUMERIC
+    printf       # LC_NUMERIC
     putwc
     putwchar
     scanf        # LC_NUMERIC
@@ -189,8 +188,7 @@ GIT_GREP_OUTPUT=$(git grep -E "[^a-zA-Z0-9_\`'\"<>](${REGEXP_LOCALE_DEPENDENT_FU
 EXIT_CODE=0
 for LOCALE_DEPENDENT_FUNCTION in "${LOCALE_DEPENDENT_FUNCTIONS[@]}"; do
     MATCHES=$(grep -E "[^a-zA-Z0-9_\`'\"<>]${LOCALE_DEPENDENT_FUNCTION}(_r|_s)?[^a-zA-Z0-9_\`'\"<>]" <<< "${GIT_GREP_OUTPUT}" | \
-        grep -vE "\.(c|cpp|h):\s*(//|\*|/\*|\").*${LOCALE_DEPENDENT_FUNCTION}" | \
-        grep -vE 'fprintf\(.*(stdout|stderr)')
+        grep -vE "\.(c|cpp|h):\s*(//|\*|/\*|\").*${LOCALE_DEPENDENT_FUNCTION}")
     if [[ ${REGEXP_IGNORE_EXTERNAL_DEPENDENCIES} != "" ]]; then
         MATCHES=$(grep -vE "${REGEXP_IGNORE_EXTERNAL_DEPENDENCIES}" <<< "${MATCHES}")
     fi
diff --git a/test/lint/lint-python-dead-code.sh b/test/lint/lint-python-dead-code.sh
index 863caa9d5c4..588ba428d75 100755
--- a/test/lint/lint-python-dead-code.sh
+++ b/test/lint/lint-python-dead-code.sh
@@ -15,5 +15,5 @@ fi
 
 vulture \
     --min-confidence 60 \
-    --ignore-names "argtypes,connection_lost,connection_made,converter,data_received,daemon,errcheck,get_ecdh_key,get_privkey,is_compressed,is_fullyvalid,msg_generic,on_*,optionxform,restype,set_privkey,profile_with_perf" \
+    --ignore-names "argtypes,connection_lost,connection_made,converter,data_received,daemon,errcheck,is_compressed,is_valid,verify_ecdsa,msg_generic,on_*,optionxform,restype,profile_with_perf" \
     $(git ls-files -- "*.py" ":(exclude)contrib/" ":(exclude)test/functional/data/invalid_txs.py")