GBA: Process multiple timer events at once, if necessary

CHANGES

@@ -122,6 +122,7 @@ Misc:
  - Qt: Set window path to loaded ROM
  - GBA Memory: Run multiple DMAs in a tight loop if they all occur before present
  - GBA Audio: Process multiple audio events at once, if necessary
+ - GBA: Process multiple timer events at once, if necessary
 
 0.2.1: (2015-05-13)
 Bugfixes:

src/gba/gba.c

@@ -244,7 +244,7 @@ static int32_t GBATimersProcessEvents(struct GBA* gba, int32_t cycles) {
 		if (timer->enable) {
 			timer->nextEvent -= cycles;
 			timer->lastEvent -= cycles;
-			if (timer->nextEvent <= 0) {
+			while (timer->nextEvent <= 0) {
 				timer->lastEvent = timer->nextEvent;
 				timer->nextEvent += timer->overflowInterval;
 				gba->memory.io[REG_TM0CNT_LO >> 1] = timer->reload;

src/gba/serialize.c

@@ -103,6 +103,10 @@ bool GBADeserialize(struct GBA* gba, const struct GBASerializedState* state) {
 		GBALog(gba, GBA_LOG_WARN, "Savestate is corrupted: overflowInterval is negative");
 		error = true;
 	}
+	if (state->timers[0].nextEvent < 0 || state->timers[1].nextEvent < 0 || state->timers[2].nextEvent < 0 || state->timers[3].nextEvent < 0) {
+		GBALog(gba, GBA_LOG_WARN, "Savestate is corrupted: timer nextEvent is negative");
+		error = true;
+	}
 	if (state->audio.eventDiff < 0) {
 		GBALog(gba, GBA_LOG_WARN, "Savestate is corrupted: audio eventDiff is negative");
 		error = true;