Re: [m17n-list] Fix segmentation fault when using ibus-m17n with vi-telex in gedit in Gnome Wayland

[Mike FABIAN]

handa <address@hidden> さんはかきました:

> In article <address@hidden>, Mike FABIAN <address@hidden> writes:
>
>> Surrounding text support in Gnome running under Wayland is broken.
>> The attached patch fixes a crash in m17n-lib caused by the broken
>> surrounding text support.
>
> Thank you for the report.  I committed your change to the repository.
> But, could you explain why the bug in Gnume leads to m17n_object_unref
> being called with NULL?

I don’t know. I just know that all input methods using surrounding text
when Gnome runs under Wayland have problems. For example:

https://bugzilla.redhat.com/show_bug.cgi?id=1625626

and:

https://bugzilla.redhat.com/show_bug.cgi?id=1637647

In most cases, this does not cause crashes but just wrong or weird
behaviour. And it works when Xorg is used instead of Wayland.

The backtrace in

https://bugzilla.redhat.com/show_bug.cgi?id=1704156


Truncated backtrace:
Thread no. 1 (10 frames)
 #0 m17n_object_unref at m17n-core.c:933
 #1 ibus_m17n_engine_callback at engine.c:1041
 #2 minput_callback at input.c:6949
 #3 get_surrounding_text at input.c:605
 #4 get_preceding_char at input.c:645
 #5 integer_value at input.c:754
 #6 resolve_expression at input.c:808
 #7 take_action_list at input.c:3480
 #8 handle_key at input.c:3619
 #9 filter at input.c:4205

showed that surrounding text was apparently used
(get_surrounding_text()). Probably something goes wrong there in
Wayland, the surrounding text received by the input method probably does
not contain what it should really contain.

But I don’t know why this causes the call of m17n_object_unref with a
NULL pointer. It should not, I guess there is another bug in ibus-m17n
trying to do something with a non-existing surrounding text.

But the fix in m17n-lib seems reasonable anyway, and it happens to make
ibus-m17n work in gedit in Gnome when using Wayland.

-- 
Mike FABIAN <address@hidden>
睡眠不足はいい仕事の敵だ。