Add policy: null signature for failed CHECK(MULTI)SIG

e41bd449ab

src/script/interpreter.h

@@ -90,6 +90,10 @@ enum
     //
     // See BIP112 for details
     SCRIPT_VERIFY_CHECKSEQUENCEVERIFY = (1U << 10),
+
+    // Signature(s) must be empty vector if an CHECK(MULTI)SIG operation failed
+    //
+    SCRIPT_VERIFY_NULLFAIL = (1U << 14),
 };
 
 bool CheckSignatureEncoding(const std::vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror);