Merge pull request #13997 from taosdata/fix/TD-16656

fix(query): fix stddev function floating point NaN value

source/libs/function/src/builtinsimpl.c

@@ -1745,10 +1745,10 @@ int32_t stddevFinalize(SqlFunctionCtx* pCtx, SSDataBlock* pBlock) {
 
   if (IS_INTEGER_TYPE(type)) {
     avg = pStddevRes->isum / ((double)pStddevRes->count);
-    pStddevRes->result = sqrt(pStddevRes->quadraticISum / ((double)pStddevRes->count) - avg * avg);
+    pStddevRes->result = sqrt(fabs(pStddevRes->quadraticISum / ((double)pStddevRes->count) - avg * avg));
   } else {
     avg = pStddevRes->dsum / ((double)pStddevRes->count);
-    pStddevRes->result = sqrt(pStddevRes->quadraticDSum / ((double)pStddevRes->count) - avg * avg);
+    pStddevRes->result = sqrt(fabs(pStddevRes->quadraticDSum / ((double)pStddevRes->count) - avg * avg));
   }
 
   return functionFinalize(pCtx, pBlock);
@@ -5362,4 +5362,4 @@ int32_t interpFunction(SqlFunctionCtx* pCtx) {
 #endif
 
   return TSDB_CODE_SUCCESS;
-}
\ No newline at end of file
+}