fix(ios): removing eventlistener multiple times ourCallbackCount shou…

…ld not be in negative value (#12339)

Fixes TIMOB-28267

iphone/TitaniumKit/TitaniumKit/Sources/API/TiProxy.m

@@ -800,10 +800,10 @@ - (void)removeEventListener:(NSArray *)args
 
   //TODO: You know, we can probably nip this in the bud and do this at a lower level,
   //Or make this less onerous.
-  int ourCallbackCount = 0;
 
   pthread_rwlock_wrlock(&listenerLock);
-  ourCallbackCount = [[listeners objectForKey:type] intValue] - 1;
+  int ourCallbackCount = [[listeners objectForKey:type] intValue];
+  ourCallbackCount = MAX(0, ourCallbackCount - 1);
   [listeners setObject:NUMINT(ourCallbackCount) forKey:type];
   pthread_rwlock_unlock(&listenerLock);
 

tests/Resources/ti.ui.window.test.js

@@ -1125,4 +1125,22 @@ describe('Titanium.UI.Window', function () {
 		// ios took 1ms repeatedly
 		// so 1 second should be enough time.
 	});
+
+	it('TIMOB-28267 On removing event listener multiple times and adding once afterward, event should be fired', finish => {
+		const win = Ti.UI.createWindow({
+			backgroundColor: '#0000ff'
+		});
+
+		win.addEventListener('open', openListener);
+		win.removeEventListener('open', openListener);
+		win.removeEventListener('open', openListener);
+		win.removeEventListener('open', openListener);
+		win.addEventListener('open', openListener);
+
+		function openListener () {
+			win.removeEventListener('open', openListener);
+			finish();
+		}
+		win.open();
+	});
 });