[TIMOB-20298] iOS:Classic Titanium app with tabs crashes when closed …

…on iOS

[JIRA](https://jira.appcelerator.org/browse/TIMOB-20298)

iphone/Classes/TiApp.h

@@ -106,6 +106,7 @@ TI_INLINE void waitForMemoryPanicCleared()   //WARNING: This must never be run o
 
 @property (nonatomic, readonly) TiContextGroupRef contextGroup;
 
+@property (nonatomic,readonly) BOOL willTerminate;
 /**
  Returns singleton instance of TiApp application object.
  */

iphone/Classes/TiApp.m

@@ -810,7 +810,7 @@ -(void)waitForKrollProcessing
 - (void)applicationWillTerminate:(UIApplication *)application
 {
 	NSNotificationCenter * theNotificationCenter = [NSNotificationCenter defaultCenter];
-
+    _willTerminate = YES;
 	//This will send out the 'close' message.
 	[theNotificationCenter postNotificationName:kTiWillShutdownNotification object:self];
 	NSCondition *condition = [[NSCondition alloc] init];

iphone/Classes/TiUITabProxy.m

@@ -271,7 +271,9 @@ -(void)closeWindow:(NSArray*)args
 {
 	TiWindowProxy *window = [args objectAtIndex:0];
 	ENSURE_TYPE(window,TiWindowProxy);
-    if (window == rootWindow) {
+    TiApp* TiAppProxy = [TiApp app];
+
+    if (window == rootWindow && ![TiAppProxy willTerminate]) {
         DebugLog(@"[ERROR] Can not close root window of the tab. Use removeTab instead");
         return;
     }