The commit below exposed a bug in dri2_add_config.
commit 3998f8c6b5
Author: Ralf Jung <post@ralfj.de>
Date: Tue Apr 9 14:09:50 2013 +0200
egl/x11: Fix initialisation of swap_interval
This little code snippet near the bottom of dri2_add_config,
if (double_buffer) {
...
conf->base.MinSwapInterval = dri2_dpy->min_swap_interval;
conf->base.MaxSwapInterval = dri2_dpy->max_swap_interval;
}
it never did what it claimed to do. The assignment never changed the value
of conf->base.MaxSwapInterval, because dri2_dpy->max_swap_interval was,
until the above exposing commit, unitialized here. That is,
conf->base.MaxSwapInterval was 0 before and after assignment. Ditto for
the min swap interval.
Above the troublesome code snippet, the call to _eglFilterArray rejects
the config as unmatching if its swap interval bounds differ from the base
config's. Before the exposing commit, at the call to _eglFilterArray, the
swap interval bounds were always [0,0], and hence no config was rejected
due to swap interval.
After the exposing commit, _eglFilterArray incorrectly rejected some
configs, which prevented dri2_egl_config::dri_double_config from getting
set for the rejected config, which resulted in a NULL pointer getting
passed into dri2CreateNewDrawable, and then segfault.
The solution: set the swap interval bounds before _eglFilterArray.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=63447
Tested-by: Lu Hua <huax.lu@intel.com>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>
d3dfce3276