fix(query): fix string compare function.

source/util/src/tcompare.c

@@ -189,7 +189,11 @@ int32_t compareLenPrefixedStr(const void *pLeft, const void *pRight) {
   int32_t minLen = MIN(len1, len2);
   int32_t ret = strncmp(varDataVal(pLeft), varDataVal(pRight), minLen);
   if (ret == 0) {
-    return len1 > len2 ? 1 : -1;
+    if (len1 == len2) {
+      return 0;
+    } else {
+      return len1 > len2 ? 1 : -1;
+    }
   } else {
     return ret > 0 ? 1 : -1;
   }