#38 mt32emu-qt midi file open dialog is case sensitive (Linux)

[Per Christian Henden]

A minor bug here.
When selecting "Play midi file", the file open dialog filter does only include lowercase names like ".mid".
In my case, I had a file in uppercase like this, FILENAME.MID, and it was visible to select from the file list.
My expectation is that both mid, MID, and Mid files are listed.

My guess is that this is what happens:
https://bugreports.qt.io/browse/QTBUG-51712
The workaround is to use QT's file dialog instead of the native one, at least on Linux.

[Serg M]

As I get from the description, this is distribution-specific issue. I don't run in such problem on my FreeBSD-12 system and in a Ubuntu 20.04 VM the file dialog opened from a native mt32emu-qt build does not filter anything at all (there is but one option All Files available), albeit the AppImage does show filters (which rather work as expected). So I think it's virtually impossible to resolve without a more detailed bug report as I might try to reproduce.

[Serg M]

OK, got it on Fedora 33. Still, the official AppImage does not suffer from the problem since not using the GTK3 dialog, and using the "*.*" / All Files filter option is a solid workaround for it.

But well, I guess it'd great to add a new build property for mt32emu-qt to improve user experience in such edge cases.