[gnome-session] gnome-session-check-accelerated: Use constant for specific sizes

[Bastien Nocera <hadess src gnome org>]

commit 63e765cf8da6fdfead08cd883ae903f13d8d1518
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Nov 13 14:48:04 2012 +0100

    gnome-session-check-accelerated: Use constant for specific sizes
    
    https://bugzilla.gnome.org/show_bug.cgi?id=688252

 tools/gnome-session-check-accelerated-helper.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/tools/gnome-session-check-accelerated-helper.c b/tools/gnome-session-check-accelerated-helper.c
index 46112f5..6086bd1 100644
--- a/tools/gnome-session-check-accelerated-helper.c
+++ b/tools/gnome-session-check-accelerated-helper.c
@@ -83,7 +83,9 @@
 #include <GL/gl.h>
 #include <GL/glx.h>
 
-static int max_texture_size = 0;
+#define SIZE_UNSET 0
+#define SIZE_ERROR -1
+static int max_texture_size = SIZE_UNSET;
 
 static inline void
 _print_error (const char *str)
@@ -289,7 +291,7 @@ _has_hardware_gl (Display *display)
          * but we'll check its value later */
         glGetIntegerv (GL_MAX_TEXTURE_SIZE, &max_texture_size);
         if (glGetError() != GL_NO_ERROR)
-                max_texture_size = -1;
+                max_texture_size = SIZE_ERROR;
 
         ret = TRUE;