[Mesa-dev] [PATCH] glxcmds: glXGetFBConfigs, fix screen bounds

[Jiri Slaby]

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

Fix this typo in glXGetFBConfigs.

Signed-off-by: Jiri Slaby <jslaby at suse.cz>
Cc: <mesa-stable at lists.freedesktop.org>
---
 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 63f492128bce..46bc214081a6 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)) {
-- 
2.8.2