1 files changed, 12 insertions, 1 deletions
diff --git a/src/test/script_tests.cpp b/src/test/script_tests.cpp
index 57b3e501af..c7a497f3a7 100644
--- a/src/test/script_tests.cpp
+++ b/src/test/script_tests.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2011-2016 The Bitcoin Core developers
+// Copyright (c) 2011-2017 The Bitcoin Core developers
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
@@ -166,6 +166,17 @@ void DoTest(const CScript& scriptPubKey, const CScript& scriptSig, const CScript
     CMutableTransaction tx2 = tx;
     BOOST_CHECK_MESSAGE(VerifyScript(scriptSig, scriptPubKey, &scriptWitness, flags, MutableTransactionSignatureChecker(&tx, 0, txCredit.vout[0].nValue), &err) == expect, message);
     BOOST_CHECK_MESSAGE(err == scriptError, std::string(FormatScriptError(err)) + " where " + std::string(FormatScriptError((ScriptError_t)scriptError)) + " expected: " + message);
+
+    // Verify that removing flags from a passing test or adding flags to a failing test does not change the result.
+    for (int i = 0; i < 16; ++i) {
+        int extra_flags = InsecureRandBits(16);
+        int combined_flags = expect ? (flags & ~extra_flags) : (flags | extra_flags);
+        // Weed out some invalid flag combinations.
+        if (combined_flags & SCRIPT_VERIFY_CLEANSTACK && ~combined_flags & (SCRIPT_VERIFY_P2SH | SCRIPT_VERIFY_WITNESS)) continue;
+        if (combined_flags & SCRIPT_VERIFY_WITNESS && ~combined_flags & SCRIPT_VERIFY_P2SH) continue;
+        BOOST_CHECK_MESSAGE(VerifyScript(scriptSig, scriptPubKey, &scriptWitness, combined_flags, MutableTransactionSignatureChecker(&tx, 0, txCredit.vout[0].nValue), &err) == expect, message + strprintf(" (with flags %x)", combined_flags));
+    }
+
 #if defined(HAVE_CONSENSUS_LIB)
     CDataStream stream(SER_NETWORK, PROTOCOL_VERSION);
     stream << tx2;