fix(query): eliminate csum/mavg result nan/inf in case of overflow

TD-16053

source/libs/function/src/builtinsimpl.c

@@ -3530,8 +3530,13 @@ int32_t csumFunction(SqlFunctionCtx* pCtx) {
       double v;
       GET_TYPED_DATA(v, double, type, data);
       pSumRes->dsum += v;
+      //check for overflow
+      if (isinf(pSumRes->dsum) || isnan(pSumRes->dsum)) {
+        colDataAppendNULL(pOutput, pos);
+      } else  {
         colDataAppend(pOutput, pos, (char *)&pSumRes->dsum, false);
       }
+    }
 
     //TODO: remove this after pTsOutput is handled
     if (pTsOutput != NULL) {
@@ -3604,7 +3609,12 @@ int32_t mavgFunction(SqlFunctionCtx* pCtx) {
 
       pInfo->points[pInfo->pos] = v;
       double result = pInfo->sum / pInfo->numOfPoints;
+      //check for overflow
+      if (isinf(result) || isnan(result)) {
+        colDataAppendNULL(pOutput, pos);
+      } else  {
         colDataAppend(pOutput, pos, (char *)&result, false);
+      }
 
       //TODO: remove this after pTsOutput is handled
       if (pTsOutput != NULL) {