From b3e195bd271eba7064eba4a1e5b04edcc34390c5 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 73c04eba..c25a199c 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 286543a0..a1fa01f0 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -249,9 +249,10 @@ 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,
@@ -308,6 +309,9 @@ 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 ccbb2224..eb5c8682 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 {