From fd95c9a52e35e994e140a925cfc01587257d4511 Mon Sep 17 00:00:00 2001
From: Hans de Goede <hdegoede@redhat.com>
Date: Mon, 26 Aug 2019 12:26:34 +0200
Subject: [PATCH xserver 12/24] xwayland: xwl_window_should_enable_viewport:
 Add extra test
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Games based on the allegro gaming library or on ClanLib-1.0 do not size
their window to match the fullscreen resolution, instead they use a
window covering the entire screen, drawing only the fullscreen resolution
part of it.

This commit adds a check for these games, so that we correctly apply a
viewport to them making fullscreen work properly for these games under
Xwayland.

Reviewed-by: Olivier Fourdan <ofourdan@redhat.com>
Acked-by: Michel Dänzer <mdaenzer@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
(cherry picked from commit 0c305dbff8a44f3fa3d6aefd372a967029a7a527)
---
 hw/xwayland/xwayland.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/hw/xwayland/xwayland.c b/hw/xwayland/xwayland.c
index 1ab5b3a28..85036adfe 100644
--- a/hw/xwayland/xwayland.c
+++ b/hw/xwayland/xwayland.c
@@ -649,6 +649,23 @@ xwl_window_should_enable_viewport(struct xwl_window *xwl_window,
         }
     }
 
+    /* 2. Test if the window uses override-redirect + vidmode
+     * and matches (fully covers) the entire screen.
+     * This path gets hit by: allegro4, ClanLib-1.0.
+     */
+    xwl_output = xwl_screen_get_first_output(xwl_screen);
+    emulated_mode = xwl_output_get_emulated_mode_for_client(xwl_output, owner);
+    if (xwl_output && xwl_window->window->overrideRedirect &&
+        emulated_mode && emulated_mode->from_vidmode &&
+        xwl_window->x == 0 && xwl_window->y == 0 &&
+        xwl_window->width  == xwl_screen->width &&
+        xwl_window->height == xwl_screen->height) {
+
+        *emulated_mode_ret = emulated_mode;
+        *xwl_output_ret = xwl_output;
+        return TRUE;
+    }
+
     return FALSE;
 }
 
-- 
2.25.2