PathConfigPane: Prevent an invalid index assert

[sepalani]

This PR prevents the following assert to be triggered:

---------------------------
wxWidgets Debug Alert
---------------------------
..\..\src\common\ctrlsub.cpp(111): assert ""pos < GetCount()"" failed in wxItemContainer::Delete(): invalid index
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Ready to be reviewed & merged.

[leoetlino]

Shouldn't the button just be disabled in that case?

[sepalani]

Ideally, it should be. I thought it was, though: https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/DolphinWX/Config/PathConfigPane.cpp#L152

[shuffle2]

Maybe the need for this changed at some point and it's screwing things up now?

[sepalani]

@shuffle2
Even if it isn't needed anymore, it's probably not what provoked this. It can only be triggered after the assert. So in best case scenario it does more work for nothing, worse one there is something wrong in OnISOPathSelectionChanged.

The only visual clue I have is the fact that the remove button is "blinking" when I do something that is triggering this function such as adding/removing paths. It seems it got disabled and then re-enabled somehow.

[shuffle2]

Oh, I didn't look which function that code was in, thought it was init code :')

[shuffle2]

https://github.com/dolphin-emu/dolphin/blob/master/Source/Core/DolphinWX/Config/PathConfigPane.cpp#L147
This is what is causing the "Remove" button to be enabled (I guess the enable is applied in a hierarchical way, so it overrides the setting put on the Remove wxButton itself).
I think it was a regression from here: bfa9cc2#diff-e369a4db42acf1ce10d24b5289031b4aR148

[shuffle2]

this seems to fix it:

...
  Bind(wxEVT_UPDATE_UI, &PathConfigPane::OnEnableIfCoreNotRunning, this);
}

void PathConfigPane::OnEnableIfCoreNotRunning(wxUpdateUIEvent& event)
{
  if (event.GetId() != m_remove_iso_path_button->GetId())
    WxEventUtils::OnEnableIfCoreNotRunning(event);
}

[shuffle2]

lgtm