[PATCH libinput 4/5] timer: Warn about negative timer offsets

[Jonas Ådahl]

Even if it may be caused by extreme stalls, warn if the timer was set to
be triggered even before 'now' when it actually is triggered, as it is
more likely a programming error.

Part of the reason for this commit was not to convert the unsigned int
to a signed int (which abs() does).

Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---
 src/timer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/timer.c b/src/timer.c
index 6a343db..a945f78 100644
--- a/src/timer.c
+++ b/src/timer.c
@@ -71,7 +71,10 @@ libinput_timer_set(struct libinput_timer *timer, uint64_t expire)
 {
 #ifndef NDEBUG
 	uint64_t now = libinput_now(timer->libinput);
-	if (abs(expire - now) > 5000)
+	if (expire < now)
+		log_bug_libinput(timer->libinput,
+				 "timer offset negative\n");
+	else if ((expire - now) > 5000ULL)
 		log_bug_libinput(timer->libinput,
 				 "timer offset more than 5s, now %"
 				 PRIu64 " expire %" PRIu64 "\n",
-- 
2.1.0