3 files changed, 23 insertions, 4 deletions
diff --git a/src/script/script.cpp b/src/script/script.cpp
index 70eb8a139b..a10b619f7d 100644
--- a/src/script/script.cpp
+++ b/src/script/script.cpp
@@ -267,3 +267,16 @@ std::string CScriptWitness::ToString() const
     }
     return ret + ")";
 }
+
+bool CScript::HasValidOps() const
+{
+    CScript::const_iterator it = begin();
+    while (it < end()) {
+        opcodetype opcode;
+        std::vector<unsigned char> item;
+        if (!GetOp(it, opcode, item) || opcode > MAX_OPCODE || item.size() > MAX_SCRIPT_ELEMENT_SIZE) {
+            return false;
+        }
+    }
+    return true;
+}
diff --git a/src/script/script.h b/src/script/script.h
index 95a5999a13..bbb37f049e 100644
--- a/src/script/script.h
+++ b/src/script/script.h
@@ -190,6 +190,9 @@ enum opcodetype
     OP_INVALIDOPCODE = 0xff,
 };
 
+// Maximum value that an opcode can be
+static const unsigned int MAX_OPCODE = OP_NOP10;
+
 const char* GetOpName(opcodetype opcode);
 
 class scriptnum_error : public std::runtime_error
@@ -630,6 +633,9 @@ public:
     bool IsPushOnly(const_iterator pc) const;
     bool IsPushOnly() const;
 
+    /** Check if the script contains valid OP_CODES */
+    bool HasValidOps() const;
+
     /**
      * Returns whether the script is guaranteed to fail at execution,
      * regardless of the initial stack. This allows outputs to be pruned
@@ -642,8 +648,9 @@ public:
 
     void clear()
     {
-        // The default std::vector::clear() does not release memory.
-        CScriptBase().swap(*this);
+        // The default prevector::clear() does not release memory
+        CScriptBase::clear();
+        shrink_to_fit();
     }
 };
 
diff --git a/src/script/sign.cpp b/src/script/sign.cpp
index 5682418546..123f88bd6f 100644
--- a/src/script/sign.cpp
+++ b/src/script/sign.cpp
@@ -141,10 +141,9 @@ static CScript PushAll(const std::vector<valtype>& values)
 bool ProduceSignature(const BaseSignatureCreator& creator, const CScript& fromPubKey, SignatureData& sigdata)
 {
     CScript script = fromPubKey;
-    bool solved = true;
     std::vector<valtype> result;
     txnouttype whichType;
-    solved = SignStep(creator, script, result, whichType, SIGVERSION_BASE);
+    bool solved = SignStep(creator, script, result, whichType, SIGVERSION_BASE);
     bool P2SH = false;
     CScript subscript;
     sigdata.scriptWitness.stack.clear();