lib/tevent: remove spectacularly complicated manual subtraction

To be completely honest, I don't quite know whether to laugh or cry at
this one:

	1 + (0xFFFFFFFF & ~(s.seen - s.count))
	== 1 + (~(s.seen - s.count))		# s.seen, s.count are uint32_t
	== s.count - s.seen			# -A == ~A + 1

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
(cherry picked from commit 4279879c9847ca069527e11ca934b8906009cad8)

diff --git a/lib/tevent/tevent_signal.c b/lib/tevent/tevent_signal.c
index f07de83a5ec43aa518f2d4c9d6744dcc0d995a83..429995318be8787bcbd664b804fa76c03b69037a 100644 (file)
--- a/lib/tevent/tevent_signal.c
+++ b/lib/tevent/tevent_signal.c
@@ -70,10 +70,7 @@ static struct sig_state {
 */
 static uint32_t sig_count(struct sigcounter s)
 {
-       if (s.count >= s.seen) {
-               return s.count - s.seen;
-       }
-       return 1 + (0xFFFFFFFF & ~(s.seen - s.count));
+       return s.count - s.seen;
 }
 
 /*