fix(query): fix to_ISO8601 function crash when processing constant

illegal inputs

TD-15211

source/libs/function/src/builtins.c

@@ -1267,6 +1267,29 @@ static bool validateMinuteRange(int8_t hour, int8_t minute, char sign) {
   return false;
 }
 
+static bool validateTimestampDigits(const SValueNode* pVal) {
+  if (IS_INTEGER_TYPE(pVal->node.resType.type)) {
+    return false;
+  }
+
+  int64_t tsVal = pVal->datum.i;
+  char fraction[20] = {0};
+  NUM_TO_STRING(pVal->node.resType.type, &tsVal, sizeof(fraction), fraction);
+  int32_t tsDigits = (int32_t)strlen(fraction);
+
+  if (tsDigits > TSDB_TIME_PRECISION_SEC_DIGITS) {
+    if (tsDigits == TSDB_TIME_PRECISION_MILLI_DIGITS ||
+        tsDigits == TSDB_TIME_PRECISION_MICRO_DIGITS ||
+        tsDigits == TSDB_TIME_PRECISION_NANO_DIGITS) {
+      return true;
+    } else {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 static bool validateTimezoneFormat(const SValueNode* pVal) {
   if (TSDB_DATA_TYPE_BINARY != pVal->node.resType.type) {
     return false;
@@ -1379,6 +1402,15 @@ static int32_t translateToIso8601(SFunctionNode* pFunc, char* pErrBuf, int32_t l
     return invaildFuncParaTypeErrMsg(pErrBuf, len, pFunc->functionName);
   }
 
+  if (QUERY_NODE_VALUE == nodeType(nodesListGetNode(pFunc->pParameterList, 0))) {
+    SValueNode* pValue = (SValueNode*)nodesListGetNode(pFunc->pParameterList, 0);
+
+    if (!validateTimestampDigits(pValue)) {
+      pFunc->node.resType = (SDataType){.bytes = 0, .type = TSDB_DATA_TYPE_BINARY};
+      return TSDB_CODE_SUCCESS;
+    }
+  }
+
   // param1
   if (numOfParams == 2) {
     SValueNode* pValue = (SValueNode*)nodesListGetNode(pFunc->pParameterList, 1);