From 9d24e68e6298f4ca2968c2950c316b72a9ddb03c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Fri, 22 Nov 2019 21:56:13 +0100
Subject: [PATCH] input: workaround buggy Sway sending bad input events

Sway 1.2 has been seen sending keyboard_key() events without first
sending a keyboard_enter() event.

This can be triggered by:

1. start a foot terminal
2. unfocus it (move focus to another window)
3. switch to a vt
4. switch back to sway
5. focus the foot terminal

At this point, Sway will *not* send the keyboard_enter() event, but
instead send a keyboard_key() event.

(furthermore, if you now unfocus the window again, sway will send a
keyboard_leave() event, still without having sent a keyboard_enter()
event).

Sway has _also_ been seen crashing in wl_pointer_motion(). Though this
was in a build without proper debug information, everything points to
a similar issue - i.e. sway is sending a motion event without first
having sent an enter event.

Workaround this by detecting this and logging a warning the first time
it happens. The event is then ignored.
---
 input.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/input.c b/input.c
index 60262b14..059ebd19 100644
--- a/input.c
+++ b/input.c
@@ -154,6 +154,17 @@ keyboard_key(void *data, struct wl_keyboard *wl_keyboard, uint32_t serial,
     struct wayland *wayl = data;
     struct terminal *term = wayl->focused;
 
+    /* Workaround buggy Sway 1.2 */
+    if (term == NULL) {
+        static bool have_warned = false;
+        if (!have_warned) {
+            have_warned = true;
+            LOG_WARN("compositor sent keyboard_key event without first sending keyboard_enter");
+        }
+        stop_repeater(wayl, -1);
+        return;
+    }
+
     assert(term != NULL);
 
     const xkb_mod_mask_t ctrl = 1 << wayl->kbd.mod_ctrl;
@@ -420,6 +431,16 @@ wl_pointer_motion(void *data, struct wl_pointer *wl_pointer,
     struct wayland *wayl = data;
     struct terminal *term = wayl->moused;
 
+    /* Workaround buggy Sway 1.2 */
+    if (term == NULL) {
+        static bool have_warned = false;
+        if (!have_warned) {
+            have_warned = true;
+            LOG_WARN("compositor sent pointer_motion event without first sending pointer_enter");
+        }
+        return;
+    }
+
     assert(term != NULL);
 
     int x = wl_fixed_to_int(surface_x) * term->scale;