Merge bitcoin/bitcoin#22428: [Refactor] Rename scriptPubKey -> exec_script

0079103 [Refactor] Rename scriptPubKey -> exec_script (sanket1729)

Pull request description:

  Rename scriptPubKey to witness_script in ExecuteWitnessScript() function to correctly reflect which script is being executed.

  For example in segwitv0, this scriptPubKey refers to the script of the form `OP_0 <script_hash>`, but witness_script refers to the script that actually hashes to the `script_hash`.

  If there is a reason why it's named this way, I would love to know

ACKs for top commit:
  MarcoFalke:
    review ACK 0079103 🖖
  theStack:
    ACK 0079103
  lsilva01:
    Code Review bitcoin/bitcoin@0079103 ACK

Tree-SHA512: 768e10e656b60b1293beb560fb7adbc2c1495e6db1f54f0c2c63109692ae0c579c856b194b33f72afd0d332159a9796c0e2bd99b79ea5c4b1803469a81301fd6

Author: MarcoFalke

src/script/interpreter.cpp

@@ -1807,16 +1807,16 @@ bool GenericTransactionSignatureChecker<T>::CheckSequence(const CScriptNum& nSeq
 template class GenericTransactionSignatureChecker<CTransaction>;
 template class GenericTransactionSignatureChecker<CMutableTransaction>;
 
-static bool ExecuteWitnessScript(const Span<const valtype>& stack_span, const CScript& scriptPubKey, unsigned int flags, SigVersion sigversion, const BaseSignatureChecker& checker, ScriptExecutionData& execdata, ScriptError* serror)
+static bool ExecuteWitnessScript(const Span<const valtype>& stack_span, const CScript& exec_script, unsigned int flags, SigVersion sigversion, const BaseSignatureChecker& checker, ScriptExecutionData& execdata, ScriptError* serror)
 {
     std::vector<valtype> stack{stack_span.begin(), stack_span.end()};
 
     if (sigversion == SigVersion::TAPSCRIPT) {
         // OP_SUCCESSx processing overrides everything, including stack element size limits
-        CScript::const_iterator pc = scriptPubKey.begin();
-        while (pc < scriptPubKey.end()) {
+        CScript::const_iterator pc = exec_script.begin();
+        while (pc < exec_script.end()) {
             opcodetype opcode;
-            if (!scriptPubKey.GetOp(pc, opcode)) {
+            if (!exec_script.GetOp(pc, opcode)) {
                 // Note how this condition would not be reached if an unknown OP_SUCCESSx was found
                 return set_error(serror, SCRIPT_ERR_BAD_OPCODE);
             }
@@ -1839,7 +1839,7 @@ static bool ExecuteWitnessScript(const Span<const valtype>& stack_span, const CS
     }
 
     // Run the script interpreter.
-    if (!EvalScript(stack, scriptPubKey, flags, checker, sigversion, execdata, serror)) return false;
+    if (!EvalScript(stack, exec_script, flags, checker, sigversion, execdata, serror)) return false;
 
     // Scripts inside witness implicitly require cleanstack behaviour
     if (stack.size() != 1) return set_error(serror, SCRIPT_ERR_CLEANSTACK);