Allow XOpenIM to return NULL?

[liuw]

https://github.com/tomaka/winit/blob/3d1c18ded9f82c17e292c03e5740cb558800c30c/src/platform/linux/x11/mod.rs#L697

Winit will panic if XOpenIM returns NULL. It is too strict IMHO. As it stands, winit can't find a valid input method.

I would much prefer the way urxvt does it:

xim = XOpenIM (display->dpy, 0, 0, 0);

if (!xim)
    return false;

This is in relation to alacritty/alacritty/issues/732

(I'm in no way an expert on X11.)

[Ralith]

I don't know much about XIM but I expect urxvt probably has the right idea. It should be possible for all XIM code to be made optional without too much pain.

[alagopus]

Confirmed on elementary OS Loki 4.4.0-97-generic using 5ac42bb13bc68c5cbc44869dc9fc9ac19402a6e6 of https://github.com/jwilm/alacritty: starting ibus restores functionality. Without ibus, alacritty is defunct now.

[jwilm]

For another reference, the terminal emulator st tries running XOpenIM with a few different locale modifiers:

/* input methods */
if ((xw.xim = XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
	XSetLocaleModifiers("@im=local");
	if ((xw.xim =  XOpenIM(xw.dpy, NULL, NULL, NULL)) == NULL) {
		XSetLocaleModifiers("@im=");
		if ((xw.xim = XOpenIM(xw.dpy,
				NULL, NULL, NULL)) == NULL) {
			die("XOpenIM failed. Could not open input"
				" device.\n");
		}
	}
}

[Limeth]

@alagopus Weird, I am getting the error even when I try to run ibus-daemon in the background. Currently trying it with 8ff3c5d170abe47554f5d2a41ad35ddc451d254d of alacritty.

[ariasuni]

I get thread 'main' panicked at 'XOpenIM failed', /home/ariasuni/.cargo/registry/src/github.com-1ecc6299db9ec823/winit-0.11.2/src/platform/linux/x11/mod.rs:959:17 when ibus is set, see my ~/.profile:

export GTK_IM_MODULE=ibus
export XMODIFIERS=@im=ibus
export QT_IM_MODULE=ibus

but is not launched for some reason.

Also, restarting ibus makes me unable to type text anymore (well, at least in alacritty, but I’m pretty sure it’s managed by winit). GTK apps works really well in that regard: they use ibus if it’s available, otherwise fallback to xim AND use ibus again as soon as it’s relaunched.

[francesca64]

@ariasuni do you still experience that panic using #424?

I'm able to reproduce the issue with restarting ibus. In fact, it seems to cause the event loop to break entirely, and in my case, the program segfaults soon afterwards. I'll look into fixing it.

[ariasuni]

Sorry, how can I test that?

[francesca64]

Assuming you're using Alacritty, you can add this to the Cargo.toml:

[patch.crates-io]
winit = { git = "https://github.com/hcpl/winit", branch = "xopenim-different-locales" }

[ariasuni]

It stills panic with the same message. :(

[francesca64]

@ariasuni Could you please try this new branch:

[patch.crates-io]
winit = { git = "https://github.com/francesca64/winit", branch = "x11-xim-refresh" }

You'll also need to run cargo update afterwards.

It should fix both of the problems, and if it doesn't, I left some printlns in for now that will help me diagnose the issue.

[ariasuni]

It works! Right now I still can’t type Japanese if I (re)start Ibus after the launch.

Here’s the console log:

IM Fallbacks(InputMethod { im: 0x7f62f0470380, name: "@im=local" })
(POTENTIAL PotentialInputMethods {
    xmodifiers: Some(
        PotentialInputMethod {
            name: "@im=ibus",
            failed: true
        }
    ),
    xim_servers: Some(
        [
            PotentialInputMethod {
                name: "@im=ibus",
                failed: true
            }
        ]
    ),
    fallbacks: [
        PotentialInputMethod {
            name: "@im=local",
            failed: false
        },
        PotentialInputMethod {
            name: "@im=",
            failed: false
        }
    ]
})

[francesca64]

@ariasuni I've pushed some more changes, so cargo update and let me know if everything works fine now.

[ariasuni]

Everything works as expected. This is awesome. ❤️