emacs-29 4f0fc3bfda3: ; Document core input events problems with XInput2

[Eli Zaretskii]

branch: emacs-29
commit 4f0fc3bfda3707fbf7f4296f29b8cfb8b8397390
Author: Po Lu <luangruo@yahoo.com>
Commit: Eli Zaretskii <eliz@gnu.org>

    ; Document core input events problems with XInput2
    
    * etc/PROBLEMS: Document problems with XInput2 and core input
    events.  (Bug#66765)
---
 etc/PROBLEMS | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/etc/PROBLEMS b/etc/PROBLEMS
index f0efbd6e411..126e876109a 100644
--- a/etc/PROBLEMS
+++ b/etc/PROBLEMS
@@ -1997,6 +1997,16 @@ modern X servers have so many other ways to send input 
to clients
 without signifying that the event is synthesized that it does not
 matter.
 
+*** Programs which use XSendEvent cannot send input events to Emacs.
+
+Emacs built to use the X Input Extension cannot receive core input
+events sent through the SendEvent server request, since these events
+intercepted by the X server when sent to input extension clients.
+
+For such programs to function again, Emacs must be run on an X server
+where the input extension is disabled, or alternatively be configured
+with the "--without-xinput2" option.
+
 * Runtime problems on character terminals
 
 ** The meta key does not work on xterm.