[gtk+] glcontext: Fix buffer age comparison

[Timm Bäder <baedert src gnome org>]

commit ec2062498f96c0f78ddf4e0c05dd2176956d6791
Author: Timm Bäder <mail baedert org>
Date:   Tue Mar 21 19:03:27 2017 +0100

    glcontext: Fix buffer age comparison
    
    The old code had a dead >=3 branch, causing flickering.

 gdk/wayland/gdkglcontext-wayland.c |    4 ++--
 gdk/x11/gdkglcontext-x11.c         |    4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)
---
diff --git a/gdk/wayland/gdkglcontext-wayland.c b/gdk/wayland/gdkglcontext-wayland.c
index f75e210..82233cf 100644
--- a/gdk/wayland/gdkglcontext-wayland.c
+++ b/gdk/wayland/gdkglcontext-wayland.c
@@ -180,12 +180,12 @@ gdk_wayland_gl_context_get_damage (GdkGLContext *context)
       eglQuerySurface (display_wayland->egl_display, egl_surface,
                        EGL_BUFFER_AGE_EXT, &buffer_age);
 
-      if (buffer_age >= 2)
+      if (buffer_age == 2)
         {
           if (window->old_updated_area[0])
             return cairo_region_copy (window->old_updated_area[0]);
         }
-      else if (buffer_age >= 3)
+      else if (buffer_age == 3)
         {
           if (window->old_updated_area[0] &&
               window->old_updated_area[1])
diff --git a/gdk/x11/gdkglcontext-x11.c b/gdk/x11/gdkglcontext-x11.c
index 8eb2cab..d76c29e 100644
--- a/gdk/x11/gdkglcontext-x11.c
+++ b/gdk/x11/gdkglcontext-x11.c
@@ -212,12 +212,12 @@ gdk_x11_gl_context_get_damage (GdkGLContext *context)
       glXQueryDrawable(dpy, shared_x11->attached_drawable,
                       GLX_BACK_BUFFER_AGE_EXT, &buffer_age);
 
-      if (buffer_age >= 2)
+      if (buffer_age == 2)
         {
           if (window->old_updated_area[0])
             return cairo_region_copy (window->old_updated_area[0]);
         }
-      else if (buffer_age >= 3)
+      else if (buffer_age == 3)
         {
           if (window->old_updated_area[0] &&
               window->old_updated_area[1])