XCB/XVideo: support parent window with ARGB visual (refs #3581)

X11 inherits properties from the parent window by default. XVideo does
not (typically) like ARGB visuals. To create plain RGB window on an ARGB
window, we need to force the color map, background and border parameters
to non-ARGB values.
(cherry picked from commit ffb2a1bbf249eec74366f9f0c8005a011661caa0)

modules/video_output/xcb/xvideo.c

@@ -329,6 +329,7 @@ static int Open (vlc_object_t *obj)
     }
 
     p_sys->window = xcb_generate_id (conn);
+    xcb_pixmap_t pixmap = xcb_generate_id (conn);
 
     /* Cache adaptors infos */
     xcb_xv_query_adaptors_reply_t *adaptors =
@@ -451,18 +452,37 @@ static int Open (vlc_object_t *obj)
         xcb_xv_format_t *f = xcb_xv_adaptor_info_formats (a);
         for (uint_fast16_t i = a->num_formats; i > 0; i--, f++)
         {
-            if (f->depth != depth)
+            if (f->depth != screen->root_depth)
                 continue; /* this would fail anyway */
 
-            const uint32_t mask =
+            uint32_t mask =
+                XCB_CW_BACK_PIXMAP |
+                XCB_CW_BACK_PIXEL |
+                XCB_CW_BORDER_PIXMAP |
+                XCB_CW_BORDER_PIXEL |
+                XCB_CW_EVENT_MASK |
+                XCB_CW_COLORMAP;
+            const uint32_t list[] = {
+                /* XCB_CW_BACK_PIXMAP */
+                pixmap,
+                /* XCB_CW_BACK_PIXEL */
+                screen->black_pixel,
+                /* XCB_CW_BORDER_PIXMAP */
+                pixmap,
+                /* XCB_CW_BORDER_PIXEL */
+                screen->black_pixel,
                 /* XCB_CW_EVENT_MASK */
-                XCB_EVENT_MASK_VISIBILITY_CHANGE;
+                XCB_EVENT_MASK_VISIBILITY_CHANGE,
+                /* XCB_CW_COLORMAP */
+                screen->default_colormap,
+            };
+
             xcb_void_cookie_t c;
 
+            xcb_create_pixmap (conn, f->depth, pixmap, screen->root, 1, 1);
             c = xcb_create_window_checked (conn, f->depth, p_sys->window,
                  p_sys->embed->handle.xid, 0, 0, 1, 1, 0,
-                 XCB_WINDOW_CLASS_INPUT_OUTPUT, f->visual,
-                 XCB_CW_EVENT_MASK, &mask);
+                 XCB_WINDOW_CLASS_INPUT_OUTPUT, f->visual, mask, list);
 
             if (!CheckError (vd, conn, "cannot create X11 window", c))
             {