0003376: TJvDBTreeView AV after deleteng of node - JEDI Issue Tracker

ID	Project	Category	View Status	Date Submitted	Last Update

0003376	JEDI VCL	00 JVCL Components	public	2005-12-22 03:29	2006-01-24 02:12

Reporter	ivan_ra	Assigned To	AHUser
Priority	normal	Severity	minor	Reproducibility	always
Status	resolved	Resolution	fixed
Product Version	3.00
Target Version		Fixed in Version	3.20

Summary	0003376: TJvDBTreeView AV after deleteng of node
Description	when you delete first topmost node TJvDBTreeView raises exception (AV). This is code: procedure TJvCustomDBTreeView.DeleteNode(Node: TTreeNode); var NewSel: TTreeNode; begin CheckDataSet; Inc(FUpdateLock); InDelete := True; try NewSel := FindNextNode(Selected); If (NewSel = nil) then NewSel := Items.GetFirstNode; // this is deleted node in this case ~~~~~~~~~~~~~~~~~~~~~~~~ FDataLink.DataSet.Delete; Selected.Free; if (NewSel <> nil) then begin NewSel.Selected := True; // AV because its already disposed ~~~~~~~~~~~~~~~~~~~~~~ Change2(NewSel); end; finally InDelete := False; Dec(FUpdateLock); end; end;
Additional Information	I suggest to test NewSel: ... If (NewSel = nil) then NewSel := Items.GetFirstNode; // this is deleted node in this case If (NewSel = Selected) then // NEW NewSel := Selected.GetNextSibling; // CODE ...
Tags	No tags attached.

ivan_ra 2006-01-23 08:10 developer ~0008424 Last edited: 2006-01-23 08:35	The cause of bug is in current code of FindNextNode. function TJvCustomDBTreeView.FindNextNode(const Node: TTreeNode): TTreeNode; begin if (Node <> nil) and (Node.Parent <> nil) then if Node.Parent.Count > 1 then if Node.Index = Node.Parent.Count - 1 then Result := Node.Parent[Node.Index - 1] else Result := Node.Parent[Node.Index + 1] else Result := Node.Parent else { if Items.Count > 1 then if Node.Index = Items.Count-1 then Result := Items[Node.Index-1] else Result := Items[Node.Index+1] else} Result := nil; end; When the node is topmost, function returns nil. In this case code of procedure DeleteNode finds First Node and and after all trys to select it. But when we delete First Node, we will get AV. So, we must check, is new selected node deleted or not: If (NewSel = Selected) then // NEW NewSel := Selected.GetNextSibling; // CODE But more correct decision is to rewrite FindNextNode for case when Node.Parent=nil (uncomment last strings): function TJvCustomDBTreeView.FindNextNode(const Node: TTreeNode): TTreeNode; begin result := nil; if Node = nil then Exit; if Node.Parent <> nil then if Node.Parent.Count > 1 then if Node.Index = Node.Parent.Count - 1 then Result := Node.Parent[Node.Index - 1] else Result := Node.Parent[Node.Index + 1] else Result := Node.Parent else if Items.Count > 1 then if Node.Index = Items.Count-1 then Result := Items[Node.Index-1] else Result := Items[Node.Index+1]; end; The problm will be solved wthout rewriting of DeleteNode code

AHUser 2006-01-24 02:12 developer ~0008437	Fixed in CVS.

Date Modified	Username	Field	Change
2005-12-22 03:29	ivan_ra	New Issue
2006-01-23 08:10	ivan_ra	Note Added: 0008424
2006-01-23 08:35	ivan_ra	Note Edited: 0008424
2006-01-24 02:12	AHUser	Status	new => resolved
2006-01-24 02:12	AHUser	Resolution	open => fixed
2006-01-24 02:12	AHUser	Assigned To	=> AHUser
2006-01-24 02:12	AHUser	Note Added: 0008437