[Development] Qt Keyboard Shortcuts broken in Qt 5.6 (since 4.8 at least). Reproducible test case included.

[jasonsu at mail-central.com]

Use of Qt Keyboard shortcuts has been broken in Qt for years.

There are lots of bugs about it in Qt and KDE projects.

This one looks close to what I'm seeing,

	Can't assign keyboard shortcut with Meta modifiers
	https://bugreports.qt.io/browse/QTCREATORBUG-9846

This one got mentioned in a few KDE bugs

	Qt LineEdit incorrectly truncates "Password" dialog elements when entered with a KDE Custom Shortcut ...
	https://bugreports.qt.io/browse/QTBUG-24304

There are lots of others.

Anyway, the point is -- shortcuts don't work.

I have a reproducible test case. It's 100% reproducible on 4 machines.  Here anyway.

The Qt shortcuts fail only when used in Qt-based applications.
They work fine in NON-Qt apps (GTK, JAVE, etc).

I can't create a Qt account, can't add to any bug (not that I'm clear on which one).  Posting the testcase here.

I'm cc'ing to a couple of developer's named I saw in those bugs.  Maybe somebody will stick this in the right place.

-------------------------------------
on:
	/usr/bin/systemsettings5 -v
		systemsettings 5.6.2

exec:
	/usr/bin/systemsettings5

open:
	Configure Desktop
		Workspace
			Shortcuts
				Custom Shortcuts
					Configure Input Actions settings

in:
	'Name' pane

right-click:
	New
		Global Shortcut
			Send Keyboard Input

rename New action:
	TEST

select:
	TEST

in:
	'Trigger' Pane

click:
	Shortcut "None"

enter:
	Meta-Ctrl-Alt-L

click:
	Apply

in:
	'Action' Pane

enter:
	Shift+3:X

click:
	Apply

(1)
open:
	LibreOffice Writer v5.1.2.2.0 10m0(Build:2) document

press:
	Meta-Ctrl-Alt-L
	OUTPUT: "#X"

(2)
open:
	Eclipse Editor v4.6 (Build:I20160405-0800) document

press:
	Meta-Ctrl-Alt-L
	OUTPUT: "#X"

(3)
open:
	KDE Kate v15.12.3 document

press:
	Meta-Ctrl-Alt-L
	OUTPUT: (none); window flashes

(4)
open:
	QtCreator v3.6.0 (based on Qt 5.6.0) document

press:
	Meta-Ctrl-Alt-L
	OUTPUT: (none); window flashes
-------------------------------------

If someone knows a bug report that this'll get fixed at, pls post it there, and let us know here.

Jason