From 964a342e5367035b02104b54d340c37dfc1aada9 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 286543a0a..a1fa01f08 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 ccbb22247..eb5c86820 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 {