[Bug 735] The WM_INPUTLANGCHANGE message is not send when switching layouts

[WineHQ Bugzilla]

https://bugs.winehq.org/show_bug.cgi?id=735

Tal Cohen  changed:

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--- Comment #30 from Tal Cohen  ---
The bug is still there in Wine 5.0.

This bug makes Wine almost useless for anyone using bidirectional language
combinations (e.g., English and Hebrew, or French and Arabic, etc.). Any
Windows control that accepts text input uses WM_INPUTLANGUAGECHANGE to adjust
from RTL to LTR text processing. Applications that do their own text processing
(e.g., browsers, Microsoft Office, graphic design programs, CAD software) also
rely on this message and are broken without it.

Switching the keyboard language on the Linux level allows me to send (e.g.)
Hebrew characters to the Windows application, but since that Windows
application does not realize it's now in RTL mode, it will completely botch the
text; it lives in an impossible situation where the input direction is LTR but
the characters provided are from an RTL language.

As Shachar noted in #11, a complete mapping to all possible (current and
future) keyboard layouts is not as critical as indicating a switch to a layout
that has a different directionality.

[Reproduced by creating my own test program, cross-compiling compiling it on
Ubuntu 18.04/Cinnamon 4.2.4 (not that it matters), and running it using
wine-5.0; running the exact same binary on Windows 10 shows that the program
itself works as expected. I then searched and found this is a known bug... for
almost 18 years.]