Merge bitcoin/bitcoin#23508: Add getdeploymentinfo RPC

a380922891 Release notes for getdeploymentinfo rpc (Anthony Towns)
240cad09ba rpc: getdeploymentinfo: include signalling info (Anthony Towns)
376c0c6dae rpc: getdeploymentinfo: include block hash/height (Anthony Towns)
a7469bcd35 rpc: getdeploymentinfo: change stats to always refer to current period (Anthony Towns)
7f15c1841b rpc: getdeploymentinfo: allow specifying a blockhash other than tip (Anthony Towns)
fd826130a0 rpc: move softfork info from getblockchaininfo to getdeploymentinfo (Anthony Towns)

Pull request description:

  The aim of this PR is to improve the ability to monitor soft fork status. It first moves the softfork section from getblockchaininfo into a new RPC named getdeploymentinfo, which is then also able to query the status of forks at an arbitrary block rather than only at the tip. In addition, bip9 status is changed to indicate the status of the given block, rather than just for the next block, and an additional field is included to indicate whether each block in the signalling period signaled.

ACKs for top commit:
  laanwj:
    Code review and lightly tested ACK a380922891
  Sjors:
    tACK a380922891
  fjahr:
    tACK a380922891

Tree-SHA512: 7417d733b47629f229c5128586569909250481a3e94356c52fe67a03fd42cd81745246e384b98c4115fb61587714c879e4bc3e5f5c74407d9f8f6773472a33cb

src/test/fuzz/rpc.cpp

@@ -120,6 +120,7 @@ const std::vector<std::string> RPC_COMMANDS_SAFE_FOR_FUZZING{
     "getchaintips",
     "getchaintxstats",
     "getconnectioncount",
+    "getdeploymentinfo",
     "getdescriptorinfo",
     "getdifficulty",
     "getindexinfo",

src/test/fuzz/versionbits.cpp

@@ -51,7 +51,7 @@ public:
 
     ThresholdState GetStateFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateFor(pindexPrev, dummy_params, m_cache); }
     int GetStateSinceHeightFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateSinceHeightFor(pindexPrev, dummy_params, m_cache); }
-    BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindexPrev) const { return AbstractThresholdConditionChecker::GetStateStatisticsFor(pindexPrev, dummy_params); }
+    BIP9Stats GetStateStatisticsFor(const CBlockIndex* pindex, std::vector<bool>* signals=nullptr) const { return AbstractThresholdConditionChecker::GetStateStatisticsFor(pindex, dummy_params, signals); }
 
     bool Condition(int32_t version) const
     {
@@ -220,7 +220,14 @@ FUZZ_TARGET_INIT(versionbits, initialize)
     CBlockIndex* prev = blocks.tip();
     const int exp_since = checker.GetStateSinceHeightFor(prev);
     const ThresholdState exp_state = checker.GetStateFor(prev);
-    BIP9Stats last_stats = checker.GetStateStatisticsFor(prev);
+
+    // get statistics from end of previous period, then reset
+    BIP9Stats last_stats;
+    last_stats.period = period;
+    last_stats.threshold = threshold;
+    last_stats.count = last_stats.elapsed = 0;
+    last_stats.possible = (period >= threshold);
+    std::vector<bool> last_signals{};
 
     int prev_next_height = (prev == nullptr ? 0 : prev->nHeight + 1);
     assert(exp_since <= prev_next_height);
@@ -241,17 +248,25 @@ FUZZ_TARGET_INIT(versionbits, initialize)
         assert(state == exp_state);
         assert(since == exp_since);
 
-        // GetStateStatistics may crash when state is not STARTED
-        if (state != ThresholdState::STARTED) continue;
-
         // check that after mining this block stats change as expected
-        const BIP9Stats stats = checker.GetStateStatisticsFor(current_block);
+        std::vector<bool> signals;
+        const BIP9Stats stats = checker.GetStateStatisticsFor(current_block, &signals);
+        const BIP9Stats stats_no_signals = checker.GetStateStatisticsFor(current_block);
+        assert(stats.period == stats_no_signals.period && stats.threshold == stats_no_signals.threshold
+               && stats.elapsed == stats_no_signals.elapsed && stats.count == stats_no_signals.count
+               && stats.possible == stats_no_signals.possible);
+
         assert(stats.period == period);
         assert(stats.threshold == threshold);
         assert(stats.elapsed == b);
         assert(stats.count == last_stats.count + (signal ? 1 : 0));
         assert(stats.possible == (stats.count + period >= stats.elapsed + threshold));
         last_stats = stats;
+
+        assert(signals.size() == last_signals.size() + 1);
+        assert(signals.back() == signal);
+        last_signals.push_back(signal);
+        assert(signals == last_signals);
     }
 
     if (exp_state == ThresholdState::STARTED) {
@@ -265,14 +280,12 @@ FUZZ_TARGET_INIT(versionbits, initialize)
     CBlockIndex* current_block = blocks.mine_block(signal);
     assert(checker.Condition(current_block) == signal);
 
-    // GetStateStatistics is safe on a period boundary
-    // and has progressed to a new period
     const BIP9Stats stats = checker.GetStateStatisticsFor(current_block);
     assert(stats.period == period);
     assert(stats.threshold == threshold);
-    assert(stats.elapsed == 0);
-    assert(stats.count == 0);
-    assert(stats.possible == true);
+    assert(stats.elapsed == period);
+    assert(stats.count == blocks_sig);
+    assert(stats.possible == (stats.count + period >= stats.elapsed + threshold));
 
     // More interesting is whether the state changed.
     const ThresholdState state = checker.GetStateFor(current_block);