4.0 breaks keyboard autorepeat in guests with xserver

[Frederick Metzengerstein]

Description:
In a linux/bsd guest within X, pressing and holding a key for a short time causes an endless repeat of that key in the guest. The release of the key gets ignored.
Example 1: pressing and holding 'a' for a few seconds results in typing of 'aaaaaaaaaaaa...' endlessly.
Example 2: pressing and holding 'Backspace' for a few seconds results in deleting all your previously typed text.

It doesn't happen within a VT in the guest. It also doesn't happen with guests that run windows, reactos or haiku for example.

The problem goes away when disabling xorgs autorepeat function via "xset -r" in the host.
Normally, this setting should not have any effect on the guest, since it has it's own autorepeat setting. So there is some conflict here.

Steps to reproduce:
Start any linux/bsd guest system with xserver, open a terminal, press and hold a key for a short time: Look how it gets typed endlessly (Try a few times if it doesn't happen immediately).
The easiest way is to run a linux live cd, like this (Link to example iso :http://download.grml.org/grml64-full_2018.12.iso)
$ qemu-system-x86_64 -enable-kvm -m 512 -net none -boot d -cdrom grml64-full_2018.12.iso

Qemu version info:
QEMU emulator version 4.0.0
Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers

System info:
Linux **** 5.0.13-arch1-1-ARCH #1 SMP PREEMPT Sun May 5 18:05:41 UTC 2019 x86_64 GNU/Linux

[Daniel Berrange (berrange)]

Adding Gerd to the CC, since this is possibly caused by recent work to keyboard state tracking code.

[Thomas Huth (th-huth)]

Fix has been included here:
https://git.qemu.org/?p=qemu.git;a=commitdiff;h=5fff13f245cddd3bc26