This bug report was migrated from our old Bugzilla tracker.

These attachments are available in the static archive:

• Patch to generate SDL_KEYDOWN/UP events for dead keys (sdl2_x11_deadkey_events.patch, text/plain, 2013-08-28 21:37:03 +0000, 1462 bytes)
• Small test-program that prints key events (sdl2_dk_test.c, text/x-csrc, 2013-08-28 21:38:31 +0000, 1988 bytes)

Reported in version: HG 2.0
Reported for operating system, platform: Linux, x86_64

Comments on the original bug report:

On 2013-08-28 21:37:03 +0000, Daniel Gibson wrote:

Created attachment 1310
Patch to generate SDL_KEYDOWN/UP events for dead keys

Pressing dead keys (e.g. ^ or `) on Linux/X11 doesn't generate SDL_KEYDOWN events, pressing another key afterwards (like for composition) just generates a "The key you just pressed is not recognized by SDL. To help get this fixed, please report this to the SDL mailing list sdl@libsdl.org X11 KeyCode 0 (-8), X11 KeySym 0x0 ((null))." message.

This is because XFilterEvent() (at the beginning of X11_DispatchEvent() in SDL_x11events.c) returns True for dead keys, so those events are discarded.
I also found out that XFilterEvents actually changes the events.
(Some more information can be found at http://forums.libsdl.org/viewtopic.php?p=38900# 38900 - note that for some reason the forum transformed "â" to "â")

I wrote a patch that in case of KeyPress/KeyRelease events saves the type and the KeyCode and, if XFilterEvent() decides to filter the event, calls SDL_SendKeyboardKey() accordingly.

This yields a similar behavior like SDL2 on Windows: There is a SDL_TEXTINPUT event with the composed char, but there are also two SDL_KEYDOWN events for the keys.

One small issue is that is that the SDL Keycode isn't the same as with the corresponding nodeadkey layout, but seems to be a direct translation of the Scancode.
E.g. on my (german) layout, The ^ key (below Esc) generates a SDL_SCANCODE_GRAVE (), but a ^ Keycode without dead keys. With dead keys enabled it generates the same Scancode, but a Keycode.
Probably X11 doesn't provide a proper mapping for that key because it's dead anyway, so the default is used.
I think that this is acceptable though and better than no key event at all (like it's the case right now).

On 2013-08-28 21:38:31 +0000, Daniel Gibson wrote:

Created attachment 1311
Small test-program that prints key events

On 2014-01-15 20:15:11 +0000, Daniel Gibson wrote:

A variant of this patch has been merged in the meantime: https://hg.libsdl.org/SDL/rev/713c6a333c33
So this can be closed.

On 2015-02-09 02:53:16 +0000, Daniel Gibson wrote:

This bug happens again in latest hg, because the fix was reverted as it caused https://bugzilla.libsdl.org/show_bug.cgi?id=2526

On 2015-12-31 05:01:21 +0000, Ryan C. Gordon wrote:

*** Bug 3076 has been marked as a duplicate of this bug. ***

On 2016-10-01 21:11:44 +0000, Sam Lantinga wrote:

Fixed by Alex's patch in bug 3136
https://hg.libsdl.org/SDL/rev/2f18ea79bc03

On 2016-10-01 21:11:53 +0000, Sam Lantinga wrote:

Fixed!