[MU4 Issue] Preferences > Shortcuts: cannot input a shortcut of the form `Shift` + special key

[cbjeukendrup]

To Reproduce Steps to reproduce the behavior:

1. Go to Preferences > Shortcuts

2. Choose an action to define a shortcut for

3. In the popup, try to enter a shortcut of the form Shift + a special key, for example:

   • Space bar
   • Backspace / delete
   • the F1...F12 keys

   -> Result: the Shift key is ignored.

Expected behavior The Shift key should not be ignored.

Platform information

• OS: at least macOS, but probably all of them

Additional context In src/framework/shortcuts/shortcutstypes.h, the method correctKeyInput actively drops the Shift modifier. I think this is a left-over from MS3's shortcuts system, which worked fundamentally different. The fix is probably as simple as removing this code.

[cbjeukendrup]

It might be good to explain the relation between this issue and #14539:

• This issue is about not being able to enter custom shortcuts of a certain form in the "Define shortcut" dialog
• #14539 is about custom shortcuts of a slightly different form that can be entered but cannot be used.

[ecstrema]

Platform information OS: at least macOS, but probably all of them

Indeed, windows is affected too. See #10745

[xlf1024]

This also applies to combining Shift with German Umlaut keys Ä Ö Ü or Scandinavian Æ Ø Å. Interestingly, the dialog always shows the uppercase variant; but only the lowercase variant triggers the specified action; Shift+[key] does nothing.

[avvvvve]

This also applies to Shift + Arrow keys. Updated the description accordingly.