Fix invalid verifying in OpenDDLParser::parseStringLiteral (#6314)

Co-authored-by: Kim Kulling <kimkulling@users.noreply.github.com>

contrib/openddlparser/code/OpenDDLParser.cpp

@@ -796,10 +796,13 @@ char *OpenDDLParser::parseStringLiteral(char *in, char *end, Value **stringData)
     if (*start == '\"') {
         ++start;
         ++in;
-        while (*in != '\"' && in != end) {
+        while (in != end && *in != '\"') {
             ++in;
             ++len;
         }
+        if (in == end) {
+            return in;
+        }
 
         *stringData = ValueAllocator::allocPrimData(Value::ValueType::ddl_string, len);
         ::strncpy((char *)(*stringData)->m_data, start, len);