ListViewGroupCollection.Add can cause corruption adding a group already added to another ListView #4001
Description
-
.NET Core Version:
Master -
Have you experienced this same bug with .NET Framework?:
Yes
Problem description:
- Add a
ListViewGrouptolistView1.Groups - Add the same
ListViewGrouptolistView2.Groups
See below test: it is very odd that group.ListView == otherListView but both otherListView.Groups and listView.Groups contain group
[WinFormsFact]
public void ListViewGroupCollection_Addd_AlreadyInOtherCollection_GetReturnsExpected()
{
using var listView = new ListView();
ListViewGroupCollection collection = listView.Groups;
using var otherListView = new ListView();
ListViewGroupCollection otherCollection = otherListView.Groups;
var group = new ListViewGroup();
otherCollection.Add(group);
// The group appears to belong to two list views.
collection.Add(group);
Assert.Same(group, collection[0]);
Assert.Same(listView, group.ListView);
Assert.Equal(group, Assert.Single(collection));
Assert.Equal(group, Assert.Single(otherCollection));
}Expected behavior:
Which one? I don't really know!
- We throw an
ArgumentExceptionorInvalidOperationExceptionwhen adding/inserting/setting? - Do nothing if
group.ListView != null(nop) and return-1 - Remove group from the other ListViewGroupCollection?
I presume the bug also exists for Item.Set and Insert
Note: implementation of ListViewGroupCollection.Add:
public int Add(ListViewGroup group)
{
if (group is null)
{
throw new ArgumentNullException(nameof(group));
}
if (Contains(group))
{
return -1;
}
CheckListViewItems(group);
group.ListView = _listView;
int index = List.Add(group);
if (_listView.IsHandleCreated)
{
_listView.InsertGroupInListView(List.Count, group);
MoveGroupItems(group);
}
return index;
}Minimal repro:
See above