Is there a bug inside GroupStyle HidesIfEmpty? - debugging

Question

I have a Windows Phone 8.1 WinRT application. I am using SemanticZoom + ListView combination to display a grouped list through a CollectionViewSource. When I remove all items from all the groups (which are ObservableCollections) and start putting the items back to these empty groups the debugger breaks and shows up with "agip.*" something at a point where it reads DISABLE_XAML_GENERATED_BREAK_ON_UNHANDLED_EXCEPTION; This used to happen for a while but now for a reason I do not know my app just exits and debugging stops without any error message; This is why I cannot remember the exact filename.
I have two questions:
1) How can I get the debugger work again i.e. to display that "agip.*" something page and not just silently quit?
2) By trial and error I managed to track down the cause of this by changing
<ListView.GroupStyle><GroupStyle HidesIfEmpty="true"
to <ListView.GroupStyle><GroupStyle HidesIfEmpty="false".
And voila my app works without any problems. Could this be a bug in the WinRT?
PS: I can achieve HidesIfEmpty behaviour by binding group header visibility to .items.count through a converter so that's not an issue here.

Answer 1

Answering your questions
1) How can I get the debugger work again i.e. to display that "agip.*" something page and not just silently quit?
Try this. Open the Exception settings window: menu Debug -> Windows -> Exception settings. Check all the exception categories.
However, I didn't get it to work. It simply breaks with an unhandled win32exceptions, not giving any idea of where did it occur and doesn't give any details on the exception, even when attaching another Visual Studio instance to debug the devenv.exe process with all exceptions handled.
2) By trial and error I managed to track down the cause of this by changing <ListView.GroupStyle><GroupStyle HidesIfEmpty="true" to <ListView.GroupStyle><GroupStyle HidesIfEmpty="false". And voila my app works without any problems. Could this be a bug in the WinRT?
Looks like it is a bug.
Your workaround
I can achieve HidesIfEmpty behaviour by binding group header visibility to .items.count through a converter so that's not an issue here.
This approach doesn't look good on Windows 10, for example, where the group header has a border on the bottom. So hiding the TextBlock doesn't hide the group header completely. (Maybe I'm doing something wrong).
I solved the problem in a different way.
Another workaround
After clearing each group of the grouped collection, try to make a delay. Like this:
foreach(var group in GroupsCollection)
{
group.Clear();
await Delay(1); // this is workaround
group.Add(newItem);
}
This has helped in my case.