xwayland: add envvar XWAYLAND_NO_GLAMOR

Not all compositors allow for customizing the Xwayland command line,
gnome-shell/mutter for example have the command line and path to
Xwayland binary hardcoded, which makes it harder for users to disable
glamor acceleration in Xwayland (glamor being used by default).

Add an environment variable XWAYLAND_NO_GLAMOR to disable glamor support
in Xwayland.

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/hw/xwayland/xwayland-glamor.c b/hw/xwayland/xwayland-glamor.c
index 87622839e..260e4e0d8 100644
--- a/hw/xwayland/xwayland-glamor.c
+++ b/hw/xwayland/xwayland-glamor.c
@@ -581,6 +581,13 @@ Bool
 xwl_glamor_init(struct xwl_screen *xwl_screen)
 {
     ScreenPtr screen = xwl_screen->screen;
+    const char *no_glamor_env;
+
+    no_glamor_env = getenv("XWAYLAND_NO_GLAMOR");
+    if (no_glamor_env && *no_glamor_env != '0') {
+        ErrorF("Disabling glamor and dri3 support, XWAYLAND_NO_GLAMOR is set\n");
+        return FALSE;
+    }
 
     if (xwl_screen->egl_context == EGL_NO_CONTEXT) {
         ErrorF("Disabling glamor and dri3, EGL setup failed\n");