[Instantobjects-cvscommit] SF.net SVN: instantobjects: [585] trunk/Source/Core/InstantPresentation.pas

[<sr...@us...>]

Revision: 585
Author:   srmitch
Date:     2006-02-12 23:25:37 -0800 (Sun, 12 Feb 2006)
ViewCVS:  http://svn.sourceforge.net/instantobjects?rev=585&view=rev

Log Message:
-----------
Fix for SF BT #1426929 bug report. For an application compiled in D2006, adding entries into a new record in a DbGrid with an attached Selector results in an application crash (stack overflow) when trying to tab from the second column. Workaround comprises the addition of a semaphore variable to avoid recursion. Changes to InstantPresentation.pas:

  TInstantCustomExposer = class(TDataSet)
  private
    ...
    FContentModifiedList: TList;
+   FInSetFieldData: Boolean;
    FMemoList: TStrings;
    ...
  end;

procedure TInstantCustomExposer.SetFieldData(Field: TField; Buffer:
Pointer);
begin
  if Assigned(Buffer) then
    Move(Buffer^, CurrentBuffer[GetFieldOffset(Field)], Field.DataSize)
  else
    FillChar(CurrentBuffer[GetFieldOffset(Field)], Field.DataSize, 0);
- if not (State in [dsCalcFields, dsInternalCalc, dsFilter, dsNewValue]) then
+ if not (State in [dsCalcFields, dsInternalCalc, dsFilter, dsNewValue]) and
+         not FInSetFieldData then
  begin
+   FInSetFieldData := True;
+   try
      PostField(Field);
      DataEvent(deFieldChange, Longint(Field));
+   finally
+     FInSetFieldData := False;
+   end;
  end;
end;

Modified Paths:
--------------
    trunk/Source/Core/InstantPresentation.pas
Modified: trunk/Source/Core/InstantPresentation.pas
===================================================================
--- trunk/Source/Core/InstantPresentation.pas	2006-02-13 07:09:19 UTC (rev 584)
+++ trunk/Source/Core/InstantPresentation.pas	2006-02-13 07:25:37 UTC (rev 585)
@@ -218,6 +218,7 @@
     FAfterPostField: TInstantFieldEvent;
     FBeforePostField: TInstantFieldEvent;
     FContentModifiedList: TList;
+    FInSetFieldData: Boolean;
     FMemoList: TStrings;
     FOnCompare: TInstantCompareObjectsEvent;
     FOnCreateObject: TInstantCreateObjectEvent;
@@ -2011,8 +2012,7 @@
     Result := Accessor.CreateObject;
 end;
 
-procedure TInstantCustomExposer.DataEvent(Event: TDataEvent;
-  Info: Integer);
+procedure TInstantCustomExposer.DataEvent(Event: TDataEvent; Info: Longint);
 var
   I: Integer;
   DataSet: TDataSet;
@@ -3742,10 +3742,16 @@
     Move(Buffer^, CurrentBuffer[GetFieldOffset(Field)], Field.DataSize)
   else
     FillChar(CurrentBuffer[GetFieldOffset(Field)], Field.DataSize, 0);
-  if not (State in [dsCalcFields, dsInternalCalc, dsFilter, dsNewValue]) then
+  if not (State in [dsCalcFields, dsInternalCalc, dsFilter, dsNewValue]) and
+          not FInSetFieldData then
   begin
-    PostField(Field);
-    DataEvent(deFieldChange, Longint(Field));
+    FInSetFieldData := True;
+    try
+      PostField(Field);
+      DataEvent(deFieldChange, Longint(Field));
+    finally
+      FInSetFieldData := False;
+    end;
   end;
 end;