fpspreadsheet: Fix missing error when cells are moved so that a circular reference formula is created (https://forum.lazarus.freepascal.org/index.php/topic,59137.msg441301.html#msg441301).

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8269 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/source/common/fpspreadsheet.pas

@@ -2274,9 +2274,12 @@ end;
 procedure TsWorksheet.MoveCell(ACell: PCell; AToRow, AToCol: Cardinal);
 var
   fromRow, fromCol: Cardinal;
+  destCell: PCell;
   sheet: TsWorksheet;
   i: Integer;
-  formula: String;
+  formula: PsFormula;
+  formulaStr: String;
+  srcHasFormula: Boolean;
 begin
   if ACell = nil then 
     exit;
@@ -2294,12 +2297,12 @@ begin
   // location. This is different from copying a formula. 
   // --> We must prevent CopyCell from adjusting the formula 
   // --> Erase the formula temporarily.
-  formula := ReadFormula(ACell);
+  formulaStr := ReadFormula(ACell);
   DeleteFormula(ACell);
   CopyCell(fromRow, fromCol, AToRow, AToCol);
   // Restore the old formula which points to the old location.
-  if formula <> ''  then
-    WriteFormula(AToRow, AToCol, formula);
+  if formulaStr <> '' then
+    WriteFormula(AToRow, AToCol, formulaStr);
     
   // Fix formula references to this cell
   for i := 0 to FWorkbook.GetWorksheetcount-1 do begin
@@ -2307,6 +2310,11 @@ begin
     sheet.Formulas.FixReferenceToMovedCell(ACell, AToRow, AToCol, self);
   end;
   
+  // Mark destination cell to contain a formula (if applicable).
+  destCell := FindCell(AToRow, AToCol);
+  formula := Formulas.FindFormula(destCell);
+  UseFormulaInCell(destCell, formula);
+  
   // Delete cell at old location
   DeleteCell(ACell);
   

components/fpspreadsheet/unit-tests/common/movetests.pas

@@ -22,6 +22,7 @@ type
 
   protected
     procedure Test_MoveCell(ATestKind: Integer);
+    procedure Test_MoveCell_CircRef(ATestKind: Integer);
 
   published
     procedure Test_MoveCell_Value;
@@ -32,6 +33,9 @@ type
     procedure Test_MoveCell_Formula_ABS;
     procedure Test_MoveCell_FormulaRef_REL;
     procedure Test_MoveCell_FormulaRef_ABS;
+    
+    procedure Test_MoveCell_FormulaToValue;
+    procedure Test_MoveCell_ValueToFormula;
   end;
 
 implementation
@@ -185,6 +189,68 @@ begin
   Test_MoveCell(8);
 end;
 
+{==============================================================================}
+
+{ In the following test an occupied cell is moved to a different location 
+  such that a circular reference is created. 
+  ATestKind = 1: value cell is moved to formula cell which points to value cell
+              2: formula cell is moved to cell to which it points. }
+procedure TSpreadMoveTests.Test_MoveCell_CircRef(ATestKind: Integer);
+const
+  VALUE_CELL_ROW = 0;
+  VALUE_CELL_COL = 0;
+  FORMULA_CELL_ROW = 11;
+  FORMULA_CELL_COL = 6;
+var
+  worksheet: TsWorksheet;
+  workbook: TsWorkbook;
+  value_cell: PCell = nil;
+  formula_cell: PCell = nil;
+  dest_cell: PCell = nil;
+begin
+  workbook := TsWorkbook.Create;
+  try
+    workbook.Options := workbook.Options + [boAutoCalc];
+
+    worksheet := workBook.AddWorksheet(MoveTestSheet);
+    
+    // Prepare the worksheet in which a cell is moved.
+    // The value cell is A1, the formula cell is B2 and it points to A1
+    value_cell := worksheet.WriteText(VALUE_CELL_ROW, VALUE_CELL_COL, 'abc');   // A1
+    formula_cell := worksheet.WriteFormula(FORMULA_CELL_ROW, FORMULA_CELL_COL, 'A1');
+    
+    // Move the cell
+    try
+      case ATestKind of
+        1: begin
+             worksheet.MoveCell(value_cell, FORMULA_CELL_ROW, FORMULA_CELL_COL);
+             dest_cell := worksheet.FindCell(FORMULA_CELL_ROW, FORMULA_CELL_COL);
+           end;  
+        2: begin
+             worksheet.MoveCell(formula_cell, VALUE_CELL_ROW, VALUE_CELL_COL);
+             dest_cell := worksheet.FindCell(VALUE_CELL_ROW, VALUE_CELL_COL);
+           end;  
+      end;
+    except
+    end;
+    
+    // In each case, the destination cell should contain a #REF! error
+    CheckEquals(true, dest_cell^.ErrorValue = errIllegalRef, 'Circular reference not detected.');
+    
+  finally
+    workbook.Free;
+  end;
+end;
+
+procedure TSpreadMoveTests.Test_MoveCell_FormulaToValue;
+begin
+  Test_MoveCell_CircRef(1);
+end;
+
+procedure TSpreadMoveTests.Test_MoveCell_ValueToFormula;
+begin
+  Test_MoveCell_CircRef(2);
+end;
 
 initialization
   RegisterTest(TSpreadMoveTests);

components/fpspreadsheet/unit-tests/common/spreadtestgui.lpi

@@ -233,7 +233,7 @@
     </Linking>
   </CompilerOptions>
   <Debugging>
-    <Exceptions Count="7">
+    <Exceptions Count="8">
       <Item1>
         <Name Value="EAbort"/>
         <Enabled Value="False"/>
@@ -259,6 +259,9 @@
       <Item7>
         <Name Value="EFPSpreadsheetReader"/>
       </Item7>
+      <Item8>
+        <Name Value="ECalcEngine"/>
+      </Item8>
     </Exceptions>
   </Debugging>
 </CONFIG>