freepascal bugtracker

--- bufdataset.pas.ori	Wed May 09 08:41:46 2012
+++ bufdataset.pas	Wed May 09 08:59:32 2012
@@ -554,7 +554,7 @@ type
     Property AutoCalcFields;
     Property Filter;
     Property Filtered;
-    Property Readonly;
+    Property ReadOnly;
     Property AfterCancel;
     Property AfterClose;
     Property AfterDelete;
@@ -1179,6 +1179,8 @@ begin
       begin
       if assigned(OldValuesBuffer) then
         FreeRecordBuffer(OldValuesBuffer);
+      if (UpdateKind = ukDelete) and assigned(BookmarkData.BookmarkData) then
+        FreeRecordBuffer(TRecordBuffer(BookmarkData.BookmarkData));
       end;
     end;
   SetLength(FUpdateBuffer,0);
@@ -1914,7 +1916,7 @@ end;
 
 procedure TCustomBufDataset.InternalDelete;
 var i : Integer;
-    RemRec, FreeRec : pointer;
+    RemRec : pointer;
     RemRecBookmrk : TBufBookmark;
 begin
   InternalSetToRecord(ActiveBuffer);
@@ -1933,15 +1935,16 @@ begin
     FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer := IntAllocRecordBuffer;
     move(RemRec^, FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer^,FRecordSize);
     end
-  else //with FIndexes[0] do
+  else
     begin
     if FUpdateBuffer[FCurrentUpdateBuffer].UpdateKind <> ukModify then
       begin
       FUpdateBuffer[FCurrentUpdateBuffer].OldValuesBuffer := nil;  //this 'disables' the updatebuffer
-      FreeRec := RemRecBookmrk.BookmarkData;  // mantis #18004
-      FreeRecordBuffer(TRecordBuffer(FreeRec));
-      // RemRecBookmrk.BookmarkData still points to just freed record buffer
-      // There could be record in update-buffer, linked to this record
+      // Do NOT release record buffer (pointed by RemRecBookmrk.BookmarkData) here
+      //  - When record is inserted and deleted(and memory released) and again inserted then same memory block can be returned
+      //    which leads to confusion, because we get same BookmarkData for distinct records
+      //  - In CancelUpdates when records are restored it is expected, that deleted records still exists in memory
+      // There also could be record(s) in update-buffer, linked to this record.
       end;
     end;
   FCurrentIndex.StoreCurrentRecIntoBookmark(@FUpdateBuffer[FCurrentUpdateBuffer].NextBookmarkData);
@@ -2009,7 +2012,8 @@ var StoreRecBM     : TBufBookmark;
           begin
           GotoBookmark(@StoreRecBM);
           if ScrollForward = grEOF then
-            ScrollBackward;
+            if ScrollBackward = grBOF then
+              ScrollLast;  // last record will be removed from index, so move to spare record
           StoreCurrentRecIntoBookmark(@StoreRecBM);
           end;
         FCurrentIndex.RemoveRecordFromIndex(Bm);

--- testbufdatasetstreams.pas.ori	Wed May 02 22:09:10 2012
+++ testbufdatasetstreams.pas	Wed May 09 09:01:16 2012
@@ -48,6 +48,7 @@ type
     procedure SeveralEditsCancelUpd;
     procedure DeleteAllCancelUpd;
     procedure DeleteAllInsertCancelUpd;
+    procedure AppendDeleteCancelUpd;
 
     procedure TestSimpleEditApplUpd;
     procedure TestSimpleDeleteApplUpd;
@@ -338,6 +339,7 @@ end;
 
 procedure TTestBufDatasetStreams.AppendDeleteChange(ADataset: TCustomBufDataset);
 begin
+  // Tests bugs #19593, #21994
   with ADataset do
   begin
     AppendRecord([16,'TestName16']);
@@ -346,6 +348,7 @@ begin
     Prior;
     Delete;  // 15 update-buffer of deleted record is linked to 16
     Delete;  // 16 inserted-deleted and linked by 15
+    AppendRecord([18,'TestName18']); // again append after delete
   end;
 end;
 
@@ -387,6 +390,11 @@ end;
 procedure TTestBufDatasetStreams.DeleteAllInsertCancelUpd;
 begin
   TestChangesCancelUpdates(@DeleteAllInsertChange);
+end;
+
+procedure TTestBufDatasetStreams.AppendDeleteCancelUpd;
+begin
+  TestChangesCancelUpdates(@AppendDeleteChange);
 end;
 
 procedure TTestBufDatasetStreams.TestBasicsXML;