From dbf18ba444e728ecddcc0e15fc44cc1fc0590b53 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Wed, 15 Oct 2025 09:41:52 +0200
Subject: [PATCH] wayland: always render a new frame after a fullscreen change

This is needed, since we disable alpha in fullscreen, and since we use
different image buffer formats (XRGB vs. ARGB) when we have alpha
vs. when we don't (and fullscreen always disables alpha).

Normally, this happens anyway, as the window is resized when going in
or out from fullscreen. But, it's technically possible for a
compositor to change an application's fullscreen state without
resizing the window.
---
 CHANGELOG.md |  4 ++++
 wayland.c    | 27 +++++++++++++++++++--------
 2 files changed, 23 insertions(+), 8 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3935889a..ed8dff69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -100,6 +100,10 @@
   ([#2179][2179]).
 * One space too much consumed when copying (or pipe:ing) contents with
   tabs ([#2194][2194])
+* Ensure we render a new frame when changing fullscreen state. Before,
+  this was automatically done if the window was also resized. But, it
+  is possible for a compositor to change an application's fullscreen
+  state without resizing the window.
 
 [2179]: https://codeberg.org/dnkl/foot/issues/2179
 [2194]: https://codeberg.org/dnkl/foot/issues/2194
diff --git a/wayland.c b/wayland.c
index 59b2a33e..bac087fb 100644
--- a/wayland.c
+++ b/wayland.c
@@ -1097,10 +1097,6 @@ xdg_surface_configure(void *data, struct xdg_surface *xdg_surface,
     else if (csd_was_enabled && !enable_csd)
         csd_destroy(win);
 
-    /* Update opaque region if fullscreen state changed */
-    if (was_fullscreen != win->is_fullscreen)
-        wayl_win_alpha_changed(win);
-
     if (enable_csd && new_width > 0 && new_height > 0) {
         if (wayl_win_csd_titlebar_visible(win))
             new_height -= win->term->conf->csd.title_height;
@@ -1139,11 +1135,26 @@ xdg_surface_configure(void *data, struct xdg_surface *xdg_surface,
     else
         term_visual_focus_out(term);
 
-    if (!resized && !term->render.pending.grid) {
+    /*
+     * Update opaque region if fullscreen state changed, also need to
+     * render, since we use different buffer types with and without
+     * alpha
+     */
+    if (was_fullscreen != win->is_fullscreen) {
+        wayl_win_alpha_changed(win);
+        render_refresh(term);
+    }
+
+    const bool will_render_soon = resized ||
+                                  term->render.refresh.grid ||
+                                  term->render.pending.grid;
+
+    if (!will_render_soon) {
         /*
-         * If we didn't resize, we won't be committing a new surface
-         * anytime soon. Some compositors require a commit in
-         * combination with an ack - make them happy.
+         * If we didn't resize, and aren't refreshing for other
+         * reasons, we won't be committing a new surface anytime
+         * soon. Some compositors require a commit in combination with
+         * an ack - make them happy.
          */
         wl_surface_commit(win->surface.surf);
     }