Description of problem:
(this is a copy from bug 660254, which was "closed EOL" (such a strange decision...)

Users with multiple keyboard layouts often setup a keyboard shortcut to switch between layouts. This is done on the X.org server level and often uses a combination of shift-keys, such as ALT+SHIFT or CTRL+SHIFT. When such a combination is used, any other keyboard shortcuts that are defined by the application and use a superset of shift-keys are no longer accessible because XKB acts on the layout switching combination on key-down and won't let the user complete the application shortcut.

For example - a common layout switching combination is ALT-SHIFT (used for MS-Windows compatibility) while ALT-SHIFT-TAB is the default "switch to previous window" shortcut in most window manager. With that setup a user can never use the "switch to previous window" action because as soon as the user holds down ALT and SHIFT together, XKB switches layout and effectively simulates the release of the shift-keys. When TAB is then clicked it does nothing.

The problem is even more serious if the user chooses CTRL-SHIFT as the layout switching shortcut (which is common on Europe) as a many applications use CTRL-SHIFT keyboard shortcuts, for example: Eclipse.

Version-Release number of selected component (if applicable):


How reproducible:
Always

Steps to Reproduce:
1.Setup multiple keyboard layouts (for example - English and French)
2.Setup ALT-SHIFT as the keyboard layout switching sequence
3.Try to use ALT-SHIFT-TAB to switch to the previous window

Actual results:
The keyboard layout changes

Expected results:
The previous window should become active.

Additional info:
This topic was discussed thoroughly in bug 660254.
Unfortunately, that bug was filed against Fedora, and, while retargeted to many versions in over-6-years lifetime, was occasionaly forgotten and "CLOSED EOL".