x11: Add back support for the damage extension

commit 14bf58ec5d dropped support
for using the DAMAGE extension since there was no code that
needed it.

We're going to need it again, however, to address an NVidia
vendor driver issue.

This commit does the plumbing to add it back.

config.h.meson

@@ -123,6 +123,9 @@
 /* Have the Xcursor library */
 #mesondefine HAVE_XCURSOR
 
+/* Have the XDAMAGE X extension */
+#mesondefine HAVE_XDAMAGE
+
 /* Have the XFIXES X extension */
 #mesondefine HAVE_XFIXES
 

gdk/x11/gdkdisplay-x11.c

@@ -1603,6 +1603,14 @@ gdk_x11_display_open (const gchar *display_name)
   }
 #endif
 
+#ifdef HAVE_XDAMAGE
+  display_x11->have_damage = FALSE;
+  if (XDamageQueryExtension (display_x11->xdisplay,
+                             &display_x11->damage_event_base,
+                             &display_x11->damage_error_base))
+    display_x11->have_damage = TRUE;
+#endif
+
   display->clipboard = gdk_x11_clipboard_new (display, "CLIPBOARD");
   display->primary_clipboard = gdk_x11_clipboard_new (display, "PRIMARY");
 

gdk/x11/gdkdisplay-x11.h

@@ -149,6 +149,12 @@ struct _GdkX11Display
   guint has_glx_multisample : 1;
   guint has_glx_visual_rating : 1;
   guint has_glx_create_es2_context : 1;
+
+#ifdef HAVE_XDAMAGE
+  gint damage_event_base;
+  gint damage_error_base;
+  guint have_damage;
+#endif
 };
 
 struct _GdkX11DisplayClass

gdk/x11/meson.build

@@ -65,6 +65,7 @@ gdk_x11_deps = [
   xext_dep,
   x11_dep,
   xcursor_dep,
+  xdamage_dep,
   xfixes_dep,
   xcomposite_dep,
   xrandr_dep,

meson.build

@@ -501,6 +501,7 @@ if x11_enabled
   xi_dep         = dependency('xi')
   xext_dep       = dependency('xext')
   xcursor_dep    = dependency('xcursor', required: false)
+  xdamage_dep    = dependency('xdamage', required: false)
   xfixes_dep     = dependency('xfixes', required: false)
   xcomposite_dep = dependency('xcomposite', required: false)
   fontconfig_dep = dependency('fontconfig')
@@ -513,6 +514,9 @@ if x11_enabled
   if xcursor_dep.found()
     x11_pkgs += ['xcursor']
   endif
+  if xdamage_dep.found()
+    x11_pkgs += ['xdamage']
+  endif
   if xfixes_dep.found()
     x11_pkgs += ['xfixes']
   endif
@@ -523,6 +527,7 @@ if x11_enabled
   atk_pkgs += ['atk-bridge-2.0']
 
   cdata.set('HAVE_XCURSOR', xcursor_dep.found())
+  cdata.set('HAVE_XDAMAGE', xdamage_dep.found())
   cdata.set('HAVE_XCOMPOSITE', xcomposite_dep.found())
   cdata.set('HAVE_XFIXES', xfixes_dep.found())