From 2d5541d6c30c67d6a469cba372b6e336a2eeb626 Mon Sep 17 00:00:00 2001 From: Povilas Kanapickas Date: Fri, 3 Sep 2021 16:23:06 +0300 Subject: 3rdparty: Fix forwards-compatibility bug in bundled xinput xcb module libxcb thinks that it knows about all device class types sent by the X server XInput extension. With the addition of touchpad gestures in XInput 2.4 and X server 21.1 this is no longer the case and libxcb fails horribly by thinking that the protocol was malformed. The X server currently has a workaround, but it would not address the following situation: - there are multiple modules within the same X client (e.g. part of the application uses Qt, another part talks to X server via another library) - both of the modules talk to XI - at least one module requests for XI 2.4 protocol support. The request for XI 2.4 disables the workaround on the X server and Qt side would crash horribly. This bug is being fixed upstream in these MRs: https://gitlab.freedesktop.org/xorg/proto/xcbproto/-/merge_requests/23 https://gitlab.freedesktop.org/xorg/lib/libxcb/-/merge_requests/20 Change-Id: Idf345271340031152b512ef59f619313be5ec226 Reviewed-by: Allan Sandfeld Jensen Reviewed-by: Shawn Rutledge --- src/3rdparty/xcb/README | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) (limited to 'src/3rdparty/xcb/README') diff --git a/src/3rdparty/xcb/README b/src/3rdparty/xcb/README index 362fa54bf8..a97d883867 100644 --- a/src/3rdparty/xcb/README +++ b/src/3rdparty/xcb/README @@ -20,3 +20,27 @@ The xcb-xinput files where modified to use system includes, see: src/3rdparty/xcb/include/xcb/fixup-xinput-h.patch src/3rdparty/xcb/libxcb/fixup-xinput-c.patch +***************************************************************** + +Additionally, a forwards compatibility bug in libxcb xinput has been addressed +by the following patch: + +src/3rdparty/xcb/libxcb/xinput-device-class-sizeof.patch + +The crux of the issue is that libxcb thinks that it knows about all device +class types sent by the X server XInput extension. With the addition of +touchpad gestures in XInput 2.4 and X server 21.1 this is no longer the case +and libxcb fails horribly by thinking that the protocol was malformed. + +The X server currently has a workaround, but it would not address the following +situation: + + - there are multiple modules within the same X client (e.g. part of the application + uses Qt, another part talks to X server via another library) + - both of the modules talk to XI + - at least one module requests for XI 2.4 protocol support. + +The request for XI 2.4 disables the workaround on the X server and Qt side would +crash horribly. + +For more details, see https://gitlab.freedesktop.org/xorg/lib/libxcb/-/merge_requests/20 -- cgit v1.2.3