Wayland: Fix kitty being killed on some Wayland compositors if a hidd…

…en window has a lot of output

Sway falls over and dies if it receives many render frame
requests. So send only a single one per damaged window and hope and pray
that the compositor hasn't dropped it. Shrug, Wayland, no surprise.
Fixes #2329

docs/changelog.rst

@@ -22,6 +22,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 
 - Linux: Workaround for broken Nvidia drivers for old cards (:iss:`456`)
 
+- Wayland: Fix kitty being killed on some Wayland compositors if a hidden window
+  has a lot of output (:iss:`2329`)
+
 
 0.17.4 [2020-05-09]
 --------------------

kitty/child-monitor.c

@@ -632,7 +632,13 @@ draw_resizing_text(OSWindow *w) {
 static inline bool
 no_render_frame_received_recently(OSWindow *w, monotonic_t now, monotonic_t max_wait) {
     bool ans = now - w->last_render_frame_received_at > max_wait;
-    if (ans && global_state.debug_rendering) log_error("No render frame received in %.2f seconds, re-requesting at: %f", monotonic_t_to_s_double(max_wait), monotonic_t_to_s_double(now));
+    if (ans && global_state.debug_rendering) {
+        if (global_state.is_wayland) {
+            log_error("No render frame received in %.2f seconds", monotonic_t_to_s_double(max_wait));
+        } else  {
+            log_error("No render frame received in %.2f seconds, re-requesting at: %f", monotonic_t_to_s_double(max_wait), monotonic_t_to_s_double(now));
+        }
+    }
     return ans;
 }
 

kitty/glfw.c

@@ -1109,8 +1109,12 @@ wayland_frame_request_callback(id_type os_window_id) {
 
 void
 request_frame_render(OSWindow *w) {
-    glfwRequestWaylandFrameEvent(w->handle, w->id, wayland_frame_request_callback);
-    w->render_state = RENDER_FRAME_REQUESTED;
+    // Some Wayland compositors are too fragile to handle multiple
+    // render frame requests, see https://github.com/kovidgoyal/kitty/issues/2329
+    if (w->render_state != RENDER_FRAME_REQUESTED) {
+        glfwRequestWaylandFrameEvent(w->handle, w->id, wayland_frame_request_callback);
+        w->render_state = RENDER_FRAME_REQUESTED;
+    }
 }
 
 void