Wayland: Fix repeated keys reported to NULL window

This fixes a race between the key repeat logic and the surface leave
event handler, which could result in repeated keys being reported with
a window of NULL.

Fixes #1704.

README.md

@@ -188,6 +188,7 @@ information on what to include when reporting a bug.
  - [Wayland] Removed support for `wl_shell` (#1443)
  - [Wayland] Bugfix: The `GLFW_HAND_CURSOR` shape used the wrong image (#1432)
  - [Wayland] Bugfix: `CLOCK_MONOTONIC` was not correctly enabled
+ - [Wayland] Bugfix: Repeated keys could be reported with `NULL` window (#1704)
  - [POSIX] Bugfix: `CLOCK_MONOTONIC` was not correctly tested for or enabled
  - [NSGL] Removed enforcement of forward-compatible flag for core contexts
  - [NSGL] Bugfix: `GLFW_COCOA_RETINA_FRAMEBUFFER` had no effect on newer
@@ -398,6 +399,7 @@ skills.
  - Torsten Walluhn
  - Patrick Walton
  - Xo Wang
+ - Waris
  - Jay Weisskopf
  - Frank Wille
  - Ryogo Yoshimura

src/wl_window.c

@@ -749,10 +749,17 @@ static void handleEvents(int timeout)
             if (read_ret != 8)
                 return;
 
-            for (i = 0; i < repeats; ++i)
-                _glfwInputKey(_glfw.wl.keyboardFocus, _glfw.wl.keyboardLastKey,
-                              _glfw.wl.keyboardLastScancode, GLFW_REPEAT,
-                              _glfw.wl.xkb.modifiers);
+            if (_glfw.wl.keyboardFocus)
+            {
+                for (i = 0; i < repeats; ++i)
+                {
+                    _glfwInputKey(_glfw.wl.keyboardFocus,
+                                  _glfw.wl.keyboardLastKey,
+                                  _glfw.wl.keyboardLastScancode,
+                                  GLFW_REPEAT,
+                                  _glfw.wl.xkb.modifiers);
+                }
+            }
         }
 
         if (fds[2].revents & POLLIN)