fpspreadsheet: Fix entering new data in existing formula not erasing formula. Add corresponding unit test cases.

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6545 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/source/common/fpspreadsheet.pas

@@ -660,6 +660,8 @@ type
     FBuiltinFontCount: Integer;
     FReadWriteFlag: TsReadWriteFlag;
     FCalculationLock: Integer;
+    FDeleteFormulaLock: Integer;
+    FNotificationLock: Integer;
     FRebuildFormulaLock: Integer;
     FActiveWorksheet: TsWorksheet;
     FOnOpenWorkbook: TNotifyEvent;
@@ -670,7 +672,6 @@ type
     FOnRemovingWorksheet: TsWorksheetEvent;
     FOnSelectWorksheet: TsWorksheetEvent;
     FOnReadCellData: TsWorkbookReadCellDataEvent;
-    FLockCount: Integer;
     FSearchEngine: TObject;
     FCryptoInfo: TsCryptoInfo;
     {FrevisionsCrypto: TsCryptoInfo;} // Commented out because it needs revision handling
@@ -797,6 +798,8 @@ type
     function FixFormulas(ACorrection: TsFormulaCorrection; AData: Pointer;
       AParam: PtrInt): boolean;
     procedure RebuildFormulas;
+    procedure LockFormulas;
+    procedure UnlockFormulas;
 
     { Clipboard }
     procedure CopyToClipboardStream(AStream: TStream; AFormat: TsSpreadsheetFormat;
@@ -1252,41 +1255,46 @@ begin
 
   // Find or create the formula cell
   lCell := GetCell(AFormula^.Row, AFormula^.Col);
-  // Assign formula result
+  FWorkbook.LockFormulas;
-  case res.ResultType of
+  try
-    rtEmpty     : WriteBlank(lCell, true);
+    // Assign formula result
-    rtError     : WriteErrorValue(lCell, res.ResError);
+    case res.ResultType of
-    rtInteger   : WriteNumber(lCell, res.ResInteger);
+      rtEmpty     : WriteBlank(lCell, true);
-    rtFloat     : WriteNumber(lCell, res.ResFloat);
+      rtError     : WriteErrorValue(lCell, res.ResError);
-    rtDateTime  : WriteDateTime(lCell, res.ResDateTime);
+      rtInteger   : WriteNumber(lCell, res.ResInteger);
-    rtString    : WriteText(lCell, res.ResString);
+      rtFloat     : WriteNumber(lCell, res.ResFloat);
-    rtHyperlink : begin
+      rtDateTime  : WriteDateTime(lCell, res.ResDateTime);
-                    link := ArgToString(res);
+      rtString    : WriteText(lCell, res.ResString);
-                    p := pos(HYPERLINK_SEPARATOR, link);
+      rtHyperlink : begin
-                    if p > 0 then
+                      link := ArgToString(res);
-                    begin
+                      p := pos(HYPERLINK_SEPARATOR, link);
-                      txt := Copy(link, p+Length(HYPERLINK_SEPARATOR), Length(link));
+                      if p > 0 then
-                      link := Copy(link, 1, p-1);
+                      begin
-                    end else
+                        txt := Copy(link, p+Length(HYPERLINK_SEPARATOR), Length(link));
-                      txt := link;
+                        link := Copy(link, 1, p-1);
-                    WriteHyperlink(lCell, link);
+                      end else
-                    WriteText(lCell, txt);
+                        txt := link;
-                  end;
+                      WriteHyperlink(lCell, link);
-    rtBoolean   : WriteBoolValue(lCell, res.ResBoolean);
+                      WriteText(lCell, txt);
-    rtCell      : begin
+                    end;
-                    lCellRef := (res.Worksheet as TsWorksheet).FindCell(res.ResRow, res.ResCol);
+      rtBoolean   : WriteBoolValue(lCell, res.ResBoolean);
-                    if lCellRef <> nil then
+      rtCell      : begin
-                      case lCellRef^.ContentType of
+                      lCellRef := (res.Worksheet as TsWorksheet).FindCell(res.ResRow, res.ResCol);
-                        cctNumber    : WriteNumber(lCell, lCellRef^.NumberValue);
+                      if lCellRef <> nil then
-                        cctDateTime  : WriteDateTime(lCell, lCellRef^.DateTimeValue);
+                        case lCellRef^.ContentType of
-                        cctUTF8String: WriteText(lCell, lCellRef^.UTF8StringValue);
+                          cctNumber    : WriteNumber(lCell, lCellRef^.NumberValue);
-                        cctBool      : WriteBoolValue(lCell, lCellRef^.Boolvalue);
+                          cctDateTime  : WriteDateTime(lCell, lCellRef^.DateTimeValue);
-                        cctError     : WriteErrorValue(lCell, lCellRef^.ErrorValue);
+                          cctUTF8String: WriteText(lCell, lCellRef^.UTF8StringValue);
-                        cctEmpty     : WriteBlank(lCell, true);
+                          cctBool      : WriteBoolValue(lCell, lCellRef^.Boolvalue);
-                      end
+                          cctError     : WriteErrorValue(lCell, lCellRef^.ErrorValue);
-                    else
+                          cctEmpty     : WriteBlank(lCell, true);
-                      WriteBlank(lCell, true);
+                        end
-                  end;
+                      else
+                        WriteBlank(lCell, true);
+                    end;
+    end;
+  finally
+    FWorkbook.UnlockFormulas;
   end;
 
   // Restore the formula. Could have been erased by WriteBlank or WriteText('')
@@ -3641,7 +3649,7 @@ end;
 -------------------------------------------------------------------------------}
 procedure TsWorksheet.DeleteFormula(ACell: PCell);
 begin
-  if HasFormula(ACell) then begin
+  if HasFormula(ACell) and (FWorkbook.FDeleteFormulaLock = 0) then begin
     FFormulas.DeleteFormula(ACell);
     ACell^.Flags := ACell^.Flags - [cfHasFormula, cf3dFormula];
   end;
@@ -4090,7 +4098,7 @@ begin
     FName := AName;
     if FWorkbook.FReadWriteFlag = rwfNormal then begin
       FWorkbook.RebuildFormulas;
-      if (FWorkbook.FLockCount = 0) and Assigned(FWorkbook.FOnRenameWorksheet) then
+      if (FWorkbook.FNotificationLock = 0) and Assigned(FWorkbook.FOnRenameWorksheet) then
         FWorkbook.FOnRenameWorksheet(FWorkbook, self);
     end;
   end;
@@ -4595,6 +4603,9 @@ begin
     end;
   end;
 
+  // Delete any pre-existing formula
+  DeleteFormula(ACell);
+
   ACell^.UTF8StringValue := AText;
   if (AText = '') then
   begin
@@ -4718,6 +4729,9 @@ end;
 procedure TsWorksheet.WriteNumber(ACell: PCell; ANumber: Double);
 begin
   if ACell <> nil then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+    // Write number to cell
     ACell^.ContentType := cctNumber;
     ACell^.NumberValue := ANumber;
     ChangedCell(ACell^.Row, ACell^.Col);
@@ -4768,6 +4782,10 @@ begin
     raise EFPSpreadsheet.Create(rsInvalidNumberFormat);
 
   if ACell <> nil then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+
+    // Write value to cell
     ACell^.ContentType := cctNumber;
     ACell^.NumberValue := ANumber;
 
@@ -4830,6 +4848,13 @@ var
   fmt: TsCellFormat;
 begin
   if ACell <> nil then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+
+    // Write value to cell
+    ACell^.ContentType := cctNumber;
+    ACell^.NumberValue := ANumber;
+
     parser := TsNumFormatParser.Create(ANumFormatString, FWorkbook.FormatSettings);
     try
       // Format string ok?
@@ -4844,9 +4869,6 @@ begin
       parser.Free;
     end;
 
-    ACell^.ContentType := cctNumber;
-    ACell^.NumberValue := ANumber;
-
     fmt := Workbook.GetCellFormat(ACell^.FormatIndex);
     if ANumFormat <> nfGeneral then begin
       fmt.NumberFormatIndex := Workbook.AddNumberFormat(ANumFormatString);
@@ -4930,6 +4952,9 @@ end;
 procedure TsWorksheet.WriteBoolValue(ACell: PCell; AValue: Boolean);
 begin
   if ACell <> nil then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+    // Write value to cell
     ACell^.ContentType := cctBool;
     ACell^.BoolValue := AValue;
     ChangedCell(ACell^.Row, ACell^.Col);
@@ -5031,8 +5056,7 @@ begin
   if ACell = nil then
     exit;
 
-  if HasFormula(ACell) then
+  DeleteFormula(ACell);
-    DeleteFormula(ACell);
 
   if AValue = '' then
   begin
@@ -5258,6 +5282,10 @@ begin
     raise EFPSpreadsheet.Create('[TsWorksheet.WriteCurrency] ANumFormat can only be nfCurrency or nfCurrencyRed');
 
   if (ACell <> nil) then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+
+    // Write value to cell
     ACell^.ContentType := cctNumber;
     ACell^.NumberValue := AValue;
 
@@ -5293,6 +5321,9 @@ end;
 procedure TsWorksheet.WriteDateTime(ACell: PCell; AValue: TDateTime);
 begin
   if ACell <> nil then begin
+    // Delete pre-existing formula
+    DeleteFormula(ACell);
+    // Write date to cell
     ACell^.ContentType := cctDateTime;
     ACell^.DateTimeValue := AValue;
     ChangedCell(ACell^.Row, ACell^.Col);
@@ -5341,6 +5372,10 @@ var
   fmt: TsCellFormat;
 begin
   if ACell <> nil then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+
+    // Write date to cell
     ACell^.ContentType := cctDateTime;
     ACell^.DateTimeValue := AValue;
 
@@ -5588,6 +5623,9 @@ end;
 procedure TsWorksheet.WriteErrorValue(ACell: PCell; AValue: TsErrorValue);
 begin
   if ACell <> nil then begin
+    // Delete any pre-existing formula
+    DeleteFormula(ACell);
+    // Write value to cell
     ACell^.ContentType := cctError;
     ACell^.ErrorValue := AValue;
     ChangedCell(ACell^.Row, ACell^.Col);
@@ -8120,7 +8158,7 @@ end;
 -------------------------------------------------------------------------------}
 procedure TsWorkbook.DisableNotifications;
 begin
-  inc(FLockCount);
+  inc(FNotificationLock);
 end;
 
 {@@ ----------------------------------------------------------------------------
@@ -8128,7 +8166,7 @@ end;
 -------------------------------------------------------------------------------}
 procedure TsWorkbook.EnableNotifications;
 begin
-  dec(FLockCount);
+  dec(FNotificationLock);
 end;
 
 {@@ ----------------------------------------------------------------------------
@@ -8136,7 +8174,7 @@ end;
 -------------------------------------------------------------------------------}
 function TsWorkbook.NotificationsEnabled: Boolean;
 begin
-  Result := (FLockCount = 0);
+  Result := (FNotificationLock = 0);
 end;
 
 {@@ ----------------------------------------------------------------------------
@@ -8399,7 +8437,7 @@ begin
     PrepareBeforeReading;
     ok := false;
     FReadWriteFlag := rwfRead;
-    inc(FLockCount);          // This locks various notifications from being sent
+    inc(FNotificationLock);          // This locks various notifications from being sent
     try
       AReader.ReadFromFile(AFileName, APassword, AParams);
       ok := true;
@@ -8410,7 +8448,7 @@ begin
       FFormatID := AFormatID;
     finally
       FReadWriteFlag := rwfNormal;
-      dec(FLockCount);
+      dec(FNotificationLock);
       if ok and Assigned(FOnOpenWorkbook) then   // ok is true if file has been read successfully
         FOnOpenWorkbook(self);   // send common notification
     end;
@@ -8535,7 +8573,7 @@ begin
     PrepareBeforeReading;
     FReadWriteFlag := rwfRead;
     ok := false;
-    inc(FLockCount);
+    inc(FNotificationLock);
     try
       AStream.Position := 0;
       AReader.ReadFromStream(AStream, APassword, AParams);
@@ -8547,7 +8585,7 @@ begin
       FFormatID := AFormatID;
     finally
       FReadWriteFlag := rwfNormal;
-      dec(FLockCount);
+      dec(FNotificationLock);
       if ok and Assigned(FOnOpenWorkbook) then   // ok is true if stream has been read successfully
         FOnOpenWorkbook(self);   // send common notification
     end;
@@ -8720,18 +8758,18 @@ begin
   // Set the name of the new worksheet.
   // For this we turn off notification of listeners. This is not necessary here
   // because it will be repeated at end when OnAddWorksheet is executed below.
-  inc(FLockCount);
+  inc(FNotificationLock);
   inc(FRebuildFormulaLock);
   try
     Result.Name := AName;
   finally
-    dec(FLockCount);
+    dec(FNotificationLock);
     dec(FRebuildFormulaLock);
   end;
 
   // Send notification for new worksheet to listeners. They get the worksheet
   // name here as well.
-  if (FLockCount = 0) and Assigned(FOnAddWorksheet) then
+  if (FNotificationLock = 0) and Assigned(FOnAddWorksheet) then
     FOnAddWorksheet(self, Result);
 
   // Make sure that there is an "active" worksheet
@@ -8766,7 +8804,7 @@ begin
     exit;
 
   Result := AddWorksheet(AWorksheet.Name, ReplaceDuplicateName);
-  inc(FLockCount);
+  inc(FNotificationLock);
   try
     for cell in AWorksheet.Cells do
     begin
@@ -8787,7 +8825,7 @@ begin
       Result.CopyRow(r, r, AWorksheet);
     end;
   finally
-    dec(FLockCount);
+    dec(FNotificationLock);
   end;
 
   Result.ChangedCell(r, c);
@@ -8971,7 +9009,7 @@ begin
   FActiveWorksheet := nil;
   FWorksheets.ForEachCall(RemoveWorksheetsCallback, nil);
   FWorksheets.Clear;
-  if (FLockCount = 0) and Assigned(FOnRemoveWorksheet) then
+  if (FNotificationLock = 0) and Assigned(FOnRemoveWorksheet) then
     FOnRemoveWorksheet(self, -1);
 end;
 
@@ -9750,6 +9788,16 @@ begin
     FWorksheets.ForEachCall(RebuildFormulasCallback, nil);
 end;
 
+procedure TsWorkbook.LockFormulas;
+begin
+  inc(FDeleteFormulaLock);
+end;
+
+procedure TsWorkbook.UnlockFormulas;
+begin
+  dec(FDeleteFormulaLock);
+end;
+
 
 { AData points to the deleted worksheet }
 procedure FixWorksheetDeletedCallback(ANode: TsExprNode; AData1, AData2: Pointer;

components/fpspreadsheet/source/common/xlscommon.pas

@@ -1913,7 +1913,7 @@ begin
     if IsDateTime(ResultFormula, nf, nfs, dt) then
       sheet.WriteDateTime(cell, dt) //, nf, nfs)
     else
-      sheet.WriteNumber(cell, ResultFormula); //, nf, nfs);
+      sheet.WriteNumber(cell, ResultFormula);
   end;
 
   { Formula token array }

components/fpspreadsheet/source/common/xlsxooxml.pas

@@ -640,6 +640,7 @@ var
   dataStr: String;
   formulaStr: String;
   formula: PsFormula;
+  isSharedFormula: Boolean;
   nodeName: String;
   sstIndex: Integer;
   number: Double;
@@ -699,7 +700,7 @@ begin
           dataStr := dataStr + GetNodeValue(tnode);
         tnode := tnode.NextSibling;
       end;
-    end else
+    end;
     if (boReadFormulas in book.Options) and (nodeName = 'f') then
     begin
       // Formula to cell
@@ -755,77 +756,83 @@ begin
     datanode := datanode.NextSibling;
   end;
 
-  // get data type
+  book.LockFormulas;  // Protect formulas from being deleted by the WriteXXXX calls
-  s := GetAttrValue(ANode, 't');   // "t" = data type
+  try
-  if (s = '') and (dataStr = '') then
+    // get data type
-    sheet.WriteBlank(cell, true)     // true --> do not erase the formula!!!
+    s := GetAttrValue(ANode, 't');   // "t" = data type
-  else
+    if (s = '') and (dataStr = '') then
-  if (s = '') or (s = 'n') then begin
+      sheet.WriteBlank(cell, true)     // true --> do not erase the formula!!!
-    // Number or date/time, depending on format
+    else
-    number := StrToFloat(dataStr, FPointSeparatorSettings);
+    if (s = '') or (s = 'n') then begin
-    if IsDateTimeFormat(numFmt) then
+      // Number or date/time, depending on format
-    begin
+      number := StrToFloat(dataStr, FPointSeparatorSettings);
-      if not IsTimeIntervalFormat(numFmt) then   // no correction of time origin for "time interval" format
+      if IsDateTimeFormat(numFmt) then
-        number := ConvertExcelDateTimeToDateTime(number, FDateMode);
+      begin
-      sheet.WriteDateTime(cell, number);
+        if not IsTimeIntervalFormat(numFmt) then   // no correction of time origin for "time interval" format
+          number := ConvertExcelDateTimeToDateTime(number, FDateMode);
+        sheet.WriteDateTime(cell, number);
+      end
+      else if IsTextFormat(numFmt) then
+        sheet.WriteText(cell, dataStr)
+      else
+        sheet.WriteNumber(cell, number);
     end
-    else if IsTextFormat(numFmt) then
-      sheet.WriteText(cell, dataStr)
     else
-      sheet.WriteNumber(cell, number);
+    if s = 's' then begin
-  end
+      // String from shared strings table
-  else
+      sstIndex := StrToInt(dataStr);
-  if s = 's' then begin
+      sheet.WriteText(cell, FSharedStrings[sstIndex]);
-    // String from shared strings table
+      // Read rich-text parameters from the stream stored in the Objects of the stringlist
-    sstIndex := StrToInt(dataStr);
+      if FSharedStrings.Objects[sstIndex] <> nil then
-    sheet.WriteText(cell, FSharedStrings[sstIndex]);
+      begin
-    // Read rich-text parameters from the stream stored in the Objects of the stringlist
+        ms := TMemoryStream(FSharedStrings.Objects[sstIndex]);
-    if FSharedStrings.Objects[sstIndex] <> nil then
+        ms.Position := 0;
-    begin
+        n := ms.ReadWord;   // Count of array elements
-      ms := TMemoryStream(FSharedStrings.Objects[sstIndex]);
+        SetLength(cell^.RichTextParams, n);
-      ms.Position := 0;
+        ms.ReadBuffer(cell^.RichTextParams[0], n*SizeOf(TsRichTextParam));
-      n := ms.ReadWord;   // Count of array elements
+      end;
-      SetLength(cell^.RichTextParams, n);
+    end else
-      ms.ReadBuffer(cell^.RichTextParams[0], n*SizeOf(TsRichTextParam));
+    if (s = 'str') or (s = 'inlineStr') then begin
-    end;
+      // literal string
-  end else
+      sheet.WriteText(cell, datastr);
-  if (s = 'str') or (s = 'inlineStr') then begin
+    end else
-    // literal string
+    if s = 'b' then
-//    formulaStr := cell^.FormulaValue;
+      // boolean
-    sheet.WriteText(cell, datastr);
+      sheet.WriteBoolValue(cell, dataStr='1')
-//    cell^.FormulaValue := formulaStr;
-  end else
-  if s = 'b' then
-    // boolean
-    sheet.WriteBoolValue(cell, dataStr='1')
-  else
-  if s = 'e' then begin
-    // error value
-    if dataStr = '#NULL!' then
-      sheet.WriteErrorValue(cell, errEmptyIntersection)
-    else if dataStr = '#DIV/0!' then
-      sheet.WriteErrorValue(cell, errDivideByZero)
-    else if dataStr = '#VALUE!' then
-      sheet.WriteErrorValue(cell, errWrongType)
-    else if dataStr = '#REF!' then
-      sheet.WriteErrorValue(cell, errIllegalRef)
-    else if dataStr = '#NAME?' then
-      sheet.WriteErrorValue(cell, errWrongName)
-    else if dataStr = '#NUM!' then
-      sheet.WriteErrorValue(cell, errOverflow)
-    else if dataStr = '#N/A' then
-      sheet.WriteErrorValue(cell, errArgError)
-    else if dataStr = '' then
-      // rare case...
-      // see http://forum.lazarus.freepascal.org/index.php/topic,38726.0.html
-      sheet.WriteBlank(cell)
     else
-      raise EFPSpreadsheetReader.Create(rsUnknownErrorType);
+    if s = 'e' then begin
-  end else
+      // error value
-    raise EFPSpreadsheetReader.Create(rsUnknownDataType);
+      if dataStr = '#NULL!' then
+        sheet.WriteErrorValue(cell, errEmptyIntersection)
+      else if dataStr = '#DIV/0!' then
+        sheet.WriteErrorValue(cell, errDivideByZero)
+      else if dataStr = '#VALUE!' then
+        sheet.WriteErrorValue(cell, errWrongType)
+      else if dataStr = '#REF!' then
+        sheet.WriteErrorValue(cell, errIllegalRef)
+      else if dataStr = '#NAME?' then
+        sheet.WriteErrorValue(cell, errWrongName)
+      else if dataStr = '#NUM!' then
+        sheet.WriteErrorValue(cell, errOverflow)
+      else if dataStr = '#N/A' then
+        sheet.WriteErrorValue(cell, errArgError)
+      else if dataStr = '' then
+        // rare case...
+        // see http://forum.lazarus.freepascal.org/index.php/topic,38726.0.html
+        sheet.WriteBlank(cell)
+      else
+        raise EFPSpreadsheetReader.Create(rsUnknownErrorType);
 
-  if FIsVirtualMode then
+
-    book.OnReadCellData(book, rowIndex, colIndex, cell);
+    end else
+      raise EFPSpreadsheetReader.Create(rsUnknownDataType);
+
+    if FIsVirtualMode then
+      book.OnReadCellData(book, rowIndex, colIndex, cell);
+
+  finally
+    book.UnlockFormulas;
+  end;
 end;
 
 procedure TsSpreadOOXMLReader.ReadCellXfs(ANode: TDOMNode);

components/fpspreadsheet/tests/formulatests.pas

@@ -38,6 +38,7 @@ type
     procedure Test_Write_Read_CalcFormulas(AFormat: TsSpreadsheetformat;
       UseRPNFormula: Boolean);
     procedure Test_Write_Read_Calc3DFormulas(AFormat: TsSpreadsheetFormat);
+    procedure Test_OverwriteFormulaTest(ATest: Integer; AFormat: TsSpreadsheetFormat);
 
   published
     // Writes out formulas & reads them back.
@@ -83,7 +84,30 @@ type
     procedure Test_Write_Read_Calc3DFormula_OOXML;
     procedure Test_Write_Read_Calc3DFormula_ODS;
 
+    { Overwrite formula with other content }
+    procedure Test_OverwriteFormula_Number_BIFF2;
+    procedure Test_OverwriteFormula_Number_BIFF5;
+    procedure Test_OverwriteFormula_Number_BIFF8;
+    procedure Test_OverwriteFormula_Number_OOXML;
+    procedure Test_OverwriteFormula_Number_ODS;
 
+    procedure Test_OverwriteFormula_Text_BIFF2;
+    procedure Test_OverwriteFormula_Text_BIFF5;
+    procedure Test_OverwriteFormula_Text_BIFF8;
+    procedure Test_OverwriteFormula_Text_OOXML;
+    procedure Test_OverwriteFormula_Text_ODS;
+
+    procedure Test_OverwriteFormula_Bool_BIFF2;
+    procedure Test_OverwriteFormula_Bool_BIFF5;
+    procedure Test_OverwriteFormula_Bool_BIFF8;
+    procedure Test_OverwriteFormula_Bool_OOXML;
+    procedure Test_OverwriteFormula_Bool_ODS;
+
+    procedure Test_OverwriteFormula_Error_BIFF2;
+    procedure Test_OverwriteFormula_Error_BIFF5;
+    procedure Test_OverwriteFormula_Error_BIFF8;
+    procedure Test_OverwriteFormula_Error_OOXML;
+    procedure Test_OverwriteFormula_Error_ODS;
   end;
 
 implementation
@@ -842,6 +866,208 @@ begin
 end;
 
 
+{------------------------------------------------------------------------------}
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormulaTest(ATest: Integer;
+  AFormat: TsSpreadsheetFormat);
+type
+  TSollValues = record
+    NumberValue: Integer;
+    TextValue: String;
+    BoolValue: Boolean;
+    ErrorValue: TsErrorValue;
+  end;
+const
+  SollValue: TSollValues = (
+    NumberValue: 100;
+    TextValue: 'abc';
+    BoolValue: false;
+    ErrorValue: errIllegalRef
+  );
+var
+  tempfile: String;
+  book: TsWorkbook;
+  sheet: TsWorksheet;
+  x: Float;
+  s: String;
+  b: Boolean;
+  err: TsErrorValue;
+  cell: PCell;
+begin
+  tempFile := GetTempFileName;
+
+  book := TsWorkbook.Create;
+  try
+    book.Options := book.Options + [boAutoCalc];
+    sheet := book.AddWorksheet('Test');
+    sheet.WriteFormula(0, 0, '=1+1');
+    case ATest of
+      0: sheet.WriteNumber(0, 0, sollValue.NumberValue);
+      1: sheet.WriteText(0, 0, sollValue.TextValue);
+      2: sheet.WriteBoolValue(0, 0, sollValue.BoolValue);
+      3: sheet.WriteErrorValue(0, 0, sollValue.ErrorValue);
+    end;
+    cell := sheet.FindCell(0, 0);
+    CheckEquals(true, cell <> nil, 'Cell A1 not found before saving');
+    case ATest of
+      0: begin
+           x := sheet.ReadAsNumber(0, 0);
+           CheckEquals(sollValue.NumberValue, x, 'Cell number content mismatch before saving');
+         end;
+      1: begin
+           s := sheet.ReadAsText(0, 0);
+           CheckEquals(sollValue.TextValue, s, 'Cell string content mismatch before saving');
+         end;
+      2: begin
+           b := cell^.BoolValue;
+           CheckEquals(sollValue.BoolValue, b, 'Cell boolean content mismatch before saving');
+         end;
+      3: begin
+           err := cell^.ErrorValue;
+           CheckEquals(ord(sollValue.ErrorValue), ord(err), 'Cell error ontent mismatch before saving');
+         end;
+    end;
+    book.WriteToFile(tempFile, AFormat, true);
+  finally
+    book.Free;
+  end;
+
+  book := TsWorkbook.Create;
+  try
+    book.Options := book.Options + [boReadFormulas, boAutoCalc];
+    book.ReadFromFile(tempFile, AFormat);
+    sheet := book.GetWorksheetByIndex(0);
+    cell := sheet.FindCell(0, 0);
+    CheckEquals(true, cell <> nil, 'Cell A1 not found after reading');
+    case ATest of
+      0: begin
+           x := sheet.ReadAsNumber(Cell);
+           CheckEquals(sollValue.NumberValue, x, 'Cell number content mismatch before saving');
+         end;
+      1: begin
+           s := sheet.ReadAsText(cell);
+           CheckEquals(sollValue.TextValue, s, 'Cell string content mismatch before saving');
+         end;
+      2: begin
+           b := cell^.BoolValue;
+           CheckEquals(sollValue.BoolValue, b, 'Cell boolean content mismatch before saving');
+         end;
+      3: begin
+           err := cell^.ErrorValue;
+           CheckEquals(ord(sollValue.ErrorValue), ord(err), 'Cell error ontent mismatch before saving');
+         end;
+    end;
+  finally
+    book.Free;
+    deleteFile(tempFile);
+  end;
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Number_BIFF2;
+begin
+  Test_OverwriteFormulaTest(0, sfExcel2);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Number_BIFF5;
+begin
+  Test_OverwriteFormulaTest(0, sfExcel5);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Number_BIFF8;
+begin
+  Test_OverwriteFormulaTest(0, sfExcel8);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Number_OOXML;
+begin
+  Test_OverwriteFormulaTest(0, sfOOXML);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Number_ODS;
+begin
+  Test_OverwriteFormulaTest(0, sfOpenDocument);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Text_BIFF2;
+begin
+  Test_OverwriteFormulaTest(1, sfExcel2);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Text_BIFF5;
+begin
+  Test_OverwriteFormulaTest(1, sfExcel5);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Text_BIFF8;
+begin
+  Test_OverwriteFormulaTest(1, sfExcel8);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Text_OOXML;
+begin
+  Test_OverwriteFormulaTest(1, sfOOXML);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Text_ODS;
+begin
+  Test_OverwriteFormulaTest(1, sfOpenDocument);
+end;
+
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Bool_BIFF2;
+begin
+  Test_OverwriteFormulaTest(2, sfExcel2);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Bool_BIFF5;
+begin
+  Test_OverwriteFormulaTest(2, sfExcel5);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Bool_BIFF8;
+begin
+  Test_OverwriteFormulaTest(2, sfExcel8);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Bool_OOXML;
+begin
+  Test_OverwriteFormulaTest(2, sfOOXML);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Bool_ODS;
+begin
+  Test_OverwriteFormulaTest(2, sfOpenDocument);
+end;
+
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Error_BIFF2;
+begin
+  Test_OverwriteFormulaTest(3, sfExcel2);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Error_BIFF5;
+begin
+  Test_OverwriteFormulaTest(3, sfExcel5);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Error_BIFF8;
+begin
+  Test_OverwriteFormulaTest(3, sfExcel8);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Error_OOXML;
+begin
+  Test_OverwriteFormulaTest(3, sfOOXML);
+end;
+
+procedure TSpreadWriteReadFormulaTests.Test_OverwriteFormula_Error_ODS;
+begin
+  Test_OverwriteFormulaTest(3, sfOpenDocument);
+end;
+
+
+
+
 initialization
   // Register so these tests are included in a full run
   RegisterTest(TSpreadWriteReadFormulaTests);