1 files changed, 34 insertions, 2 deletions

diff --git a/backends/timer/default/default-timer.cpp b/backends/timer/default/default-timer.cpp
index 8480fcc7ee..e1aadb62b8 100644
--- a/backends/timer/default/default-timer.cpp
+++ b/backends/timer/default/default-timer.cpp
@@ -24,10 +24,10 @@
 #include "common/util.h"
 #include "common/system.h"
 
-
 struct TimerSlot {
 	Common::TimerManager::TimerProc callback;
 	void *refCon;
+	Common::String id;
 	uint32 interval;	// in microseconds
 
 	uint32 nextFireTime;	// in milliseconds
@@ -109,13 +109,28 @@ void DefaultTimerManager::handler() {
 	}
 }
 
-bool DefaultTimerManager::installTimerProc(TimerProc callback, int32 interval, void *refCon) {
+bool DefaultTimerManager::installTimerProc(TimerProc callback, int32 interval, void *refCon, const Common::String &id) {
 	assert(interval > 0);
 	Common::StackLock lock(_mutex);
 
+	if (_callbacks.contains(id)) {
+		if (_callbacks[id] != callback) {
+			error("Different callbacks are referred by same name (%s)", id.c_str());
+		}
+	}
+	TimerSlotMap::const_iterator i;
+
+	for (i = _callbacks.begin(); i != _callbacks.end(); ++i) {
+		if (i->_value == callback) {
+			error("Same callback is referred by different names (%s vs %s)", i->_key.c_str(), id.c_str());
+		}
+	}
+	_callbacks[id] = callback;
+
 	TimerSlot *slot = new TimerSlot;
 	slot->callback = callback;
 	slot->refCon = refCon;
+	slot->id = id;
 	slot->interval = interval;
 	slot->nextFireTime = g_system->getMillis() + interval / 1000;
 	slot->nextFireTimeMicro = interval % 1000;
@@ -146,4 +161,21 @@ void DefaultTimerManager::removeTimerProc(TimerProc callback) {
 			slot = slot->next;
 		}
 	}
+
+	// We need to remove all names referencing the timer proc here.
+	// 
+	// Else we run into troubles, when the client code removes and readds timer
+	// callbacks.
+	//
+	// Another issues occurs when one plays a game with ALSA as music driver,
+	// does RTL and starts a different engine game with ALSA as music driver.
+	// In this case the MPU401 code will add different timer procs with the
+	// same name, resulting in two different callbacks added with the same
+	// name and causing installTimerProc to error out.
+	// A good test case is running a SCUMM with ALSA output and then a KYRA
+	// game for example.
+	for (TimerSlotMap::iterator i = _callbacks.begin(), end = _callbacks.end(); i != end; ++i) {
+		if (i->_value == callback)
+			_callbacks.erase(i);
+	}
 }