Description of problem:
My Xserver crashes reliable after running small Java sample which should display Input box:

import javax.swing.JFrame;
import javax.swing.JOptionPane;
[..]
        JFrame frame = new JFrame();
        String s = JOptionPane.showInputDialog(frame, text);

Same program used as in bug 1389886, but now quite different backtrace.
Seems some memory corruption taking place.

Version-Release number of selected component:
xorg-x11-server-Xorg-1.19.0-1.fc25

Additional info:
reporter:       libreport-2.8.0
backtrace_rating: 4
cmdline:        /usr/libexec/Xorg vt2 -displayfd 3 -auth /run/user/1000/gdm/Xauthority -nolisten tcp -background none -noreset -keeptty -verbose 3
crash_function: alloc_data
executable:     /usr/libexec/Xorg
global_pid:     6648
kernel:         4.8.11-300.fc25.x86_64
pkg_fingerprint: 4089 D8F2 FDB1 9C98
pkg_vendor:     Fedora Project
runlevel:       N 5
type:           CCpp
uid:            1000

Truncated backtrace:
Thread no. 1 (10 frames)
 #6 alloc_data at pixman-region.c:213
 #7 pixman_rect_alloc at pixman-region.c:465
 #8 pixman_op at pixman-region.c:828
 #9 pixman_region_union at pixman-region.c:1440
 #10 RegionUnion at ../../include/regionstr.h:241
 #11 damageRegionProcessPending at damage.c:293
 #12 damageComposite at damage.c:507
 #13 ProcRenderComposite at render.c:695
 #14 Dispatch at dispatch.c:469
 #15 dix_main at main.c:287