Popover fails to restablish default widget on GtkFilechooser
Normally, when the file chooser shows up and the filename editbox is still focused, pressing Enter confirms the dialog and saves the file, as one would expect.
After clicking the "New folder" button (and creating a folder), if I refocus the filename editbox (let's say I needed to change the name a little), pressing Enter does nothing at all – even though it worked originally (as said in first paragraph).
Version: gtk 3.24.x
What happens, it's that when the 'New Folder' popover is created, it correctly stores internally the 'Enter' button as the default widget to be restablished later (when the popover is dismished), but when that time comes the popover fails to restablish it. So the filechooser ends up with a NULL default widget and so ENTER key does nothing.
I'm submitting a MR with a commit message explaining the fix.
This issue was originally part of #996