fix error in sort operation

source/common/src/tdatablock.c

@@ -176,6 +176,8 @@ int32_t colDataAppend(SColumnInfoData* pColumnInfoData, uint32_t currentRow, con
 
 static void doBitmapMerge(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, const SColumnInfoData* pSource,
                           int32_t numOfRow2) {
+  if (numOfRow2 <= 0) return;
+
   uint32_t total = numOfRow1 + numOfRow2;
 
   if (BitmapLen(numOfRow1) < BitmapLen(total)) {
@@ -190,22 +192,32 @@ static void doBitmapMerge(SColumnInfoData* pColumnInfoData, int32_t numOfRow1, c
 
   if (remindBits == 0) {  // no need to shift bits of bitmap
     memcpy(pColumnInfoData->nullbitmap + BitmapLen(numOfRow1), pSource->nullbitmap, BitmapLen(numOfRow2));
-  } else {
-    int32_t len = BitmapLen(numOfRow2);
-    int32_t i = 0;
+    return;
+  }
 
   uint8_t* p = (uint8_t*)pSource->nullbitmap;
-    pColumnInfoData->nullbitmap[BitmapLen(numOfRow1) - 1] |= (p[0] >> remindBits);
+  pColumnInfoData->nullbitmap[BitmapLen(numOfRow1) - 1] |= (p[0] >> remindBits);  // copy remind bits
 
-    uint8_t* start = (uint8_t*)&pColumnInfoData->nullbitmap[BitmapLen(numOfRow1)];
-    while (i < len) {
-      start[i] |= (p[i] << shiftBits);
-      i += 1;
+  if (BitmapLen(numOfRow1) == BitmapLen(total)) {
+    return;
+  }
+
+  int32_t len = BitmapLen(numOfRow2);
+  int32_t i = 0;
 
-      if (i > 1) {
-        start[i - 1] |= (p[i] >> remindBits);
+  uint8_t* start = (uint8_t*)&pColumnInfoData->nullbitmap[BitmapLen(numOfRow1)];
+  int32_t overCount = BitmapLen(total) - BitmapLen(numOfRow1);
+  while (i < len) { // size limit of pSource->nullbitmap
+    if (i >= 1) {
+      start[i - 1] |= (p[i] >> remindBits); //copy remind bits
     }
+
+    if (i >= overCount) { // size limit of pColumnInfoData->nullbitmap
+      return;
     }
+
+    start[i] |= (p[i] << shiftBits);  //copy shift bits
+    i += 1;
   }
 }
 
@@ -408,7 +420,7 @@ int32_t blockDataSplitRows(SSDataBlock* pBlock, bool hasVarCol, int32_t startInd
     }
 
     return TSDB_CODE_SUCCESS;
-  } else {
+  }
   // iterate the rows that can be fit in this buffer page
   int32_t size = (headerSize + colHeaderSize);
 
@@ -445,7 +457,7 @@ int32_t blockDataSplitRows(SSDataBlock* pBlock, bool hasVarCol, int32_t startInd
   // all fit in
   *stopIndex = numOfRows - 1;
   return TSDB_CODE_SUCCESS;
-  }
+
 }
 
 SSDataBlock* blockDataExtractBlock(SSDataBlock* pBlock, int32_t startIndex, int32_t rowCount) {

source/libs/executor/test/sortTests.cpp

@@ -83,7 +83,7 @@ SSDataBlock* getSingleColStrBlock(void* param) {
 
   SColumnInfoData colInfo = {0};
   colInfo.info.type = TSDB_DATA_TYPE_NCHAR;
-  colInfo.info.bytes = TSDB_NCHAR_SIZE * 16;
+  colInfo.info.bytes = TSDB_NCHAR_SIZE * 16 + VARSTR_HEADER_SIZE;
   colInfo.info.colId = 1;
   colInfo.varmeta.offset = static_cast<int32_t *>(taosMemoryCalloc(pInfo->pageRows, sizeof(int32_t)));