Merge #10483: scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL

90d4d89 scripted-diff: Use the C++11 keyword nullptr to denote the pointer literal instead of the macro NULL (practicalswift)

Pull request description:

  Since C++11 the macro `NULL` may be:
  * an integer literal with value zero, or
  * a prvalue of type `std::nullptr_t`

  By using the C++11 keyword `nullptr` we are guaranteed a prvalue of type `std::nullptr_t`.

  For a more thorough discussion, see "A name for the null pointer: nullptr" (Sutter &
  Stroustrup), http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2007/n2431.pdf

  With this patch applied there are no `NULL` macro usages left in the repo:

  ```
  $ git grep NULL -- "*.cpp" "*.h" | egrep -v '(/univalue/|/secp256k1/|/leveldb/|_NULL|NULLDUMMY|torcontrol.*NULL|NULL cert)' | wc -l
  0
  ```

  The road towards `nullptr` (C++11) is split into two PRs:
  * `NULL` → `nullptr` is handled in PR #10483 (scripted, this PR)
  * `0` → `nullptr` is handled in PR #10645 (manual)

Tree-SHA512: 3c395d66f2ad724a8e6fed74b93634de8bfc0c0eafac94e64e5194c939499fefd6e68f047de3083ad0b4eff37df9a8a3a76349aa17d55eabbd8e0412f140a297

src/core_write.cpp

@@ -102,7 +102,7 @@ std::string ScriptToAsmStr(const CScript& script, const bool fAttemptSighashDeco
                     // this won't decode correctly formatted public keys in Pubkey or Multisig scripts due to
                     // the restrictions on the pubkey formats (see IsCompressedOrUncompressedPubKey) being incongruous with the
                     // checks in CheckSignatureEncoding.
-                    if (CheckSignatureEncoding(vch, SCRIPT_VERIFY_STRICTENC, NULL)) {
+                    if (CheckSignatureEncoding(vch, SCRIPT_VERIFY_STRICTENC, nullptr)) {
                         const unsigned char chSigHashType = vch.back();
                         if (mapSigHashTypes.count(chSigHashType)) {
                             strSigHashDecode = "[" + mapSigHashTypes.find(chSigHashType)->second + "]";