Merge pull request #17972 from taosdata/fix/TD-20246

refactor: optimize interp linear interpolation ignore NULL values during calculation

source/libs/executor/inc/executorimpl.h

@@ -776,7 +776,6 @@ typedef struct STimeSliceOperatorInfo {
   SArray*              pPrevRow;     // SArray<SGroupValue>
   SArray*              pNextRow;     // SArray<SGroupValue>
   SArray*              pLinearInfo;  // SArray<SFillLinearInfo>
-  bool                 fillLastPoint;
   bool                 isPrevRowSet;
   bool                 isNextRowSet;
   int32_t              fillType;      // fill type

source/libs/executor/inc/tfill.h

@@ -36,7 +36,8 @@ typedef struct SFillColInfo {
 typedef struct SFillLinearInfo {
   SPoint  start;
   SPoint  end;
-  bool    hasNull;
+  bool    isStartSet;
+  bool    isEndSet;
   int16_t type;
   int32_t bytes;
 } SFillLinearInfo;