From c26665ec4d44bf2774df3127085c7db233cf08de Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Sat, 31 Jul 2021 11:41:27 +0530
Subject: [PATCH] Wayland: If the compositor turns off server side decorations
 after turning them on do not draw client side decorations

This matches the behavior of GNOME based clients and in any case sway
seems to get very confused if CSD is drawn.

Fixes #3888
---
 docs/changelog.rst |  3 +++
 glfw/wl_window.c   | 19 +++++++++++++++----
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/docs/changelog.rst b/docs/changelog.rst
index 5651307d7..38b7cf5c5 100644
--- a/docs/changelog.rst
+++ b/docs/changelog.rst
@@ -23,6 +23,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 
 - Linux binary: Remove any RPATH build artifacts from bundled libraries
 
+- Wayland: If the compositor turns off server side decorations after turning
+  them on do not draw client side decorations (:iss:`3888`)
+
 
 0.22.0 [2021-07-26]
 ----------------------
diff --git a/glfw/wl_window.c b/glfw/wl_window.c
index 41c427214..dc0ab6209 100644
--- a/glfw/wl_window.c
+++ b/glfw/wl_window.c
@@ -255,13 +255,22 @@ dispatchChangesAfterConfigure(_GLFWwindow *window, int32_t width, int32_t height
 }
 
 
-static void xdgDecorationHandleConfigure(void* data,
+static void
+xdgDecorationHandleConfigure(void* data,
                                          struct zxdg_toplevel_decoration_v1* decoration UNUSED,
                                          uint32_t mode)
 {
     _GLFWwindow* window = data;
 
-    window->wl.decorations.serverSide = (mode == ZXDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
+    bool has_server_side_decorations = (mode == ZXDG_TOPLEVEL_DECORATION_V1_MODE_SERVER_SIDE);
+    debug("XDG decoration configure event received: Has server side decorations: %d\n", has_server_side_decorations);
+    if (!has_server_side_decorations && window->wl.decorations.serverSide) {
+        // this can happen for example on sway where it has a "border toggle" function
+        // that turns on/off the server side decorations. In such a case, we dont turn
+        // on client side decorations, as that causes things to break.
+        return;
+    }
+    window->wl.decorations.serverSide = has_server_side_decorations;
     ensure_csd_resources(window);
 }
 
@@ -488,7 +497,8 @@ static const struct xdg_surface_listener xdgSurfaceListener = {
     xdgSurfaceHandleConfigure
 };
 
-static void setXdgDecorations(_GLFWwindow* window)
+static void
+setXdgDecorations(_GLFWwindow* window)
 {
     if (_glfw.wl.decorationManager)
     {
@@ -510,7 +520,8 @@ static void setXdgDecorations(_GLFWwindow* window)
     }
 }
 
-static bool createXdgSurface(_GLFWwindow* window)
+static bool
+createXdgSurface(_GLFWwindow* window)
 {
     window->wl.xdg.surface = xdg_wm_base_get_xdg_surface(_glfw.wl.wmBase,
                                                          window->wl.surface);