musescore/MuseScore — pull request #43 by fyzix (2012-08-13 16:38:23+00:00)
Title: Allow pressing backspace in the shortcut dialog (#11645)

At least on Mac, I wanted to be able to reconfigure
the delete action to work with backspace. It seemed
not to work at first, but it actually did - but only if the
focus was not on the edit fields in the dialog.

There seems to be a bug in Qt, in the implementation of
QLineEdit: it swallows the Backspace key even if the
edit field is in read-only mode. Looks like a forgotten
code path to me.

As a workaround, we grab the backspace keyboard events
before they are fed to any of the line edit fields and
handle them ourselves.