From 8c3c6987dbdffa74eb1fee901b4ab1d73641e29f Mon Sep 17 00:00:00 2001
From: Simon Ser <contact@emersion.fr>
Date: Thu, 11 Aug 2022 09:09:37 +0200
Subject: [PATCH] backend/wayland: fix touch device not added on startup

We were firing the new_input signal on backend initialization,
before the compositor had the chance to add a listener for it.

Mimick what's done for wl_keyboard: if the backend hasn't been
started, delay wl_touch initialization.

Closes: https://gitlab.freedesktop.org/wlroots/wlroots/-/issues/3473
---
 backend/wayland/backend.c | 4 ++++
 backend/wayland/seat.c    | 6 ++++--
 include/backend/wayland.h | 2 ++
 3 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/backend/wayland/backend.c b/backend/wayland/backend.c
index 07df6912..2980324f 100644
--- a/backend/wayland/backend.c
+++ b/backend/wayland/backend.c
@@ -424,6 +424,10 @@ static bool backend_start(struct wlr_backend *backend) {
 			init_seat_keyboard(seat);
 		}
 
+		if (seat->wl_touch) {
+			init_seat_touch(seat);
+		}
+
 		if (wl->tablet_manager) {
 			init_seat_tablet(seat);
 		}
diff --git a/backend/wayland/seat.c b/backend/wayland/seat.c
index d1c75b39..655f9dad 100644
--- a/backend/wayland/seat.c
+++ b/backend/wayland/seat.c
@@ -212,7 +212,7 @@ static const struct wlr_touch_impl touch_impl = {
 	.name = "wl-touch",
 };
 
-static void init_seat_touch(struct wlr_wl_seat *seat) {
+void init_seat_touch(struct wlr_wl_seat *seat) {
 	assert(seat->wl_touch);
 
 	char name[128] = {0};
@@ -333,7 +333,9 @@ static void seat_handle_capabilities(void *data, struct wl_seat *wl_seat,
 		wlr_log(WLR_DEBUG, "seat '%s' offering touch", seat->name);
 
 		seat->wl_touch = wl_seat_get_touch(wl_seat);
-		init_seat_touch(seat);
+		if (backend->started) {
+			init_seat_touch(seat);
+		}
 	}
 	if (!(caps & WL_SEAT_CAPABILITY_TOUCH) && seat->wl_touch != NULL) {
 		wlr_log(WLR_DEBUG, "seat '%s' dropping touch", seat->name);
diff --git a/include/backend/wayland.h b/include/backend/wayland.h
index 5baaac9d..3a0b1327 100644
--- a/include/backend/wayland.h
+++ b/include/backend/wayland.h
@@ -144,6 +144,8 @@ void init_seat_pointer(struct wlr_wl_seat *seat);
 void finish_seat_pointer(struct wlr_wl_seat *seat);
 void create_pointer(struct wlr_wl_seat *seat, struct wlr_wl_output *output);
 
+void init_seat_touch(struct wlr_wl_seat *seat);
+
 void init_seat_tablet(struct wlr_wl_seat *seat);
 void finish_seat_tablet(struct wlr_wl_seat *seat);