Wrong filtering of desktop files in file dialog

[tsujan]

Expected Behavior

.desktop should be treated like other extensions by LXQt file dialog.

Current Behavior

When "File type:" is .desktop, no desktop file is shown by the file dialog.

Steps to Reproduce (for bugs)

FeatherPad filters by extension with "Save As":

1. Open a desktop file with FP.
2. Use "Save As".

Then, the containing folder will be opened in LXQt file dialog but no desktop file will be shown, unless the filter is changes to "All Files (*)".

That's while if FP is set to use Qt's non-native file dialog, all desktop files will be shown and the opened one will be selected and scrolled to correctly.

System Information

Latest git