From: Jiri Slaby <jslaby@suse.cz>
Date: Tue May 17 08:22:42 2016 +0200
Subject: glxcmds: glXGetFBConfigs, fix screen bounds
Patch-mainline: Not yet
Git-repo: git://anongit.freedesktop.org/git/mesa/mesa
Git-commit: 6aaa258229ec09f84ca51a728e125009ecee2d16
References: boo#980382

Bounds of screen are 0 (inclusive) and ScreenCount(dpy) (exclusive).
The upper bound was too high: ScreenCount(dpy) (inclusive).

This causes a crash invoked by java3d which passes down an invalid
screen:
6  0x00007f0e5198ba70 in <signal handler called> () at /lib64/libc.so.6
7  0x00007f0e14531e14 in glXGetFBConfigs (dpy=<optimized out>, screen=1, nelements=nelements@entry=0x7f0dab3c522c) at glxcmds.c:1660
8  0x00007f0e14532f7f in glXChooseFBConfig (dpy=<optimized out>, screen=<optimized out>, attribList=0x7f0dab3c54e0, nitems=0x7f0dab3c535c) at glxcmds.c:1611
9  0x00007f0e1478d29b in find_S_FBConfigs () at /usr/lib64/libj3dcore-ogl.so
10 0x00007f0e1478d3dc in find_S_S_FBConfigs () at /usr/lib64/libj3dcore-ogl.so
11 0x00007f0e1478d567 in find_AA_S_S_FBConfigs () at /usr/lib64/libj3dcore-ogl.so
12 0x00007f0e1478d728 in find_DB_AA_S_S_FBConfigs () at /usr/lib64/libj3dcore-ogl.so
13 0x00007f0e1478d97c in Java_javax_media_j3d_X11NativeConfigTemplate3D_chooseOglVisual () at /usr/lib64/libj3dcore-ogl.so

While ScreenCount(dpy) is actually 1:
(gdb) p dpy->nscreens
$2 = 1
screen=1 is passed to glXGetFBConfigs.

Easily reproducible by:
	#include <stdio.h>

	#include <X11/Xlib.h>
	#include <GL/glx.h>

	int main()
	{
		unsigned a;
		int n;
		Display *d = XOpenDisplay(":0");
		GLXFBConfig *cfg;

		for (a = 0; a <= ScreenCount(d); a++)
			cfg = glXGetFBConfigs(d, a, &n);

		XCloseDisplay(d);

		return 0;
	}

Fix this typo in glXGetFBConfigs.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: <mesa-stable@lists.freedesktop.org>
Signed-off-by: Egbert Eich <eich@suse.com>
---
 src/glx/glxcmds.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/glx/glxcmds.c b/src/glx/glxcmds.c
index 63f4921..46bc214 100644
--- a/src/glx/glxcmds.c
+++ b/src/glx/glxcmds.c
@@ -1657,7 +1657,7 @@ glXGetFBConfigs(Display * dpy, int screen, int *nelements)
 
    *nelements = 0;
    if (priv && (priv->screens != NULL)
-       && (screen >= 0) && (screen <= ScreenCount(dpy))
+       && (screen >= 0) && (screen < ScreenCount(dpy))
        && (priv->screens[screen]->configs != NULL)
        && (priv->screens[screen]->configs->fbconfigID
 	   != (int) GLX_DONT_CARE)) {