[BUG] Characters are often disappearing when typing messages with ibus-m17n into https://web.whatsapp.com

[mike-fabian]

This bug was discovered by @Mahmudul-hasan613 .

See:

mike-fabian/m17n-db-bn-national-jatiya#1 (comment)
mike-fabian/m17n-db-bn-national-jatiya#1 (comment)
mike-fabian/m17n-db-bn-national-jatiya#1 (comment)
mike-fabian/m17n-db-bn-national-jatiya#1 (comment)

This looks similar to https://bugzilla.redhat.com/show_bug.cgi?id=1850832 (The Gujarati & Hindi itrans methods are not able to type sentences correctly.) where characters were kind of “randomly” disappearing in various input methods when used on Gnome Wayland.

But:

• I cannot reproduce https://bugzilla.redhat.com/show_bug.cgi?id=1850832 on Gnome Wayland in Fedora 37 anymore
• The problem described here happens both on Xorg and Wayland
• It seems to happen only in https://web.whatsapp.com
• It happens both in firefox and google-chrome
• It seems to happen with almost all ibus-m17n engines

[mike-fabian]

• it does not happen when using the same m17n input method with ibus-typing-booster instead of ibus-m17n

[mike-fabian]

Video showing the problem using

• mr-gamabhana
• hi-itrans
• t-latn-post

as examples (but it happens with others as well)

With mr-gamabhana, I type g space, with hi-itrans I type a space, with t-latn-post I type u space.

The character typed at the beginning of the Whatsapp message entry disappears in most cases.

Sometimes it remains. If the line is not empty anymore, the problem is gone:

Peek.2022-09-19.18-34.mp4

[mike-fabian]

When debugging this with gdb I found that the ibus_m17n_engine_reset () callback is called many times when it should not be called. It should only be called when the cursor is moved with the mouse. For a similar problem in Wayland see: https://gitlab.gnome.org/GNOME/gtk/-/issues/5191