From eb4fa8e4f59e923a3d763d1f64ec5ea996de0a2b Mon Sep 17 00:00:00 2001
From: Satyeshwar Singh <satyeshwar.singh@intel.com>
Date: Wed, 27 Feb 2013 15:26:23 -0500
Subject: [PATCH] evdev: Wait for SYN event before sending events over to the
 client

The issue was that touch::down event from the compositor to client apps
would send the previous motion events coordinates and this obviously made
the client do the wrong thing. This happened because we were not waiting
for a SYN event to come from evdev before sending down, motion or up events.

https://bugs.freedesktop.org/show_bug.cgi?id=51909
---
 src/evdev-touchpad.c | 2 +-
 src/evdev.c          | 6 +++++-
 src/evdev.h          | 1 +
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/evdev-touchpad.c b/src/evdev-touchpad.c
index 73c04eba4..c25a199ca 100644
--- a/src/evdev-touchpad.c
+++ b/src/evdev-touchpad.c
@@ -481,7 +481,7 @@ touchpad_update_state(struct touchpad_dispatch *touchpad, uint32_t time)
 			touchpad->device->rel.dx = wl_fixed_from_double(dx);
 			touchpad->device->rel.dy = wl_fixed_from_double(dy);
 			touchpad->device->pending_events |=
-				EVDEV_RELATIVE_MOTION;
+				EVDEV_RELATIVE_MOTION | EVDEV_SYN;
 		} else if (touchpad->finger_state == TOUCHPAD_FINGERS_TWO) {
 			if (dx != 0.0)
 				notify_axis(touchpad->device->seat,
diff --git a/src/evdev.c b/src/evdev.c
index 321992e85..ccadf92a5 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -234,9 +234,10 @@ evdev_flush_motion(struct evdev_device *device, uint32_t time)
 {
 	struct weston_seat *master = device->seat;
 
-	if (!device->pending_events)
+	if (!(device->pending_events & EVDEV_SYN))
 		return;
 
+	device->pending_events &= ~EVDEV_SYN;
 	if (device->pending_events & EVDEV_RELATIVE_MOTION) {
 		notify_motion(master, time,
 			      master->seat.pointer->x + device->rel.dx,
@@ -292,6 +293,9 @@ fallback_process(struct evdev_dispatch *dispatch,
 	case EV_KEY:
 		evdev_process_key(device, event, time);
 		break;
+	case EV_SYN:
+		device->pending_events |= EVDEV_SYN;
+		break;
 	}
 }
 
diff --git a/src/evdev.h b/src/evdev.h
index 7222de3fe..bb931f3ce 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -34,6 +34,7 @@ enum evdev_event_type {
 	EVDEV_ABSOLUTE_MT_MOTION = (1 << 2),
 	EVDEV_ABSOLUTE_MT_UP = (1 << 3),
 	EVDEV_RELATIVE_MOTION = (1 << 4),
+	EVDEV_SYN = (1 << 5),
 };
 
 enum evdev_device_capability {