Air application hangs instead of throwing MemoryError - actionscript-3

Question

I'm trying to make my application throw MemoryError by creating a very long string, but it hangs instead of throwing it.
I tried this with air sdk 3.4 and 3.8, both release and debug builds.
Sometimes when I close the app in a force way, eclipse shows something like app exited with error code:out of memory.
I also noticed that console contains line [Unload SWF] myapp.swf after executing the code(if you add trace(str.length) after doubling the string, you'll see that it happens after length 369098752).
You can see here AS3 Reference for MemoryError that this is legitimate way of causing MemoryError.
So, how can I really catch those MemoryErrors instead of allowing app to crash?
Here is my code:
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
creationComplete="onCreation(event)"
>
<fx:Script>
<![CDATA[
import mx.controls.Alert;
import mx.events.FlexEvent;
import avmplus.getQualifiedClassName;
protected var str:String = 'ssssssssssssssssssssss';
protected function onCreation(event:FlexEvent):void{
var serverString:String = unescape(Capabilities.serverString);
try{
while(true){
str+=str;
}
}catch(e:MemoryError){
Alert.show('memoryError');
}
}
]]>
</fx:Script>
</s:WindowedApplication>
update:
I improved test app, now you can clearly see that no error or uncaught error is thrown.
It crashes when memory usage reaches 1700-1750MB.
I found some bugs that resemble my case in bugbase, but they are related to air 2.x and marked as fixed/not a bug. I can't find any similar bug for air 3.x.
Bug: App crashes when allocates >1.7GB
Bug: App crashes when approaches 2GB
Can anybody reproduce?
<?xml version="1.0" encoding="utf-8"?>
<s:WindowedApplication xmlns:fx="http://ns.adobe.com/mxml/2009"
xmlns:s="library://ns.adobe.com/flex/spark"
xmlns:mx="library://ns.adobe.com/flex/mx"
applicationComplete="onCreation(event)"
>
<fx:Script>
<![CDATA[
import flash.utils.setInterval;
import mx.controls.Alert;
import mx.events.FlexEvent;
import avmplus.getQualifiedClassName;
protected var vectors:Vector.<Vector.<uint>>= new Vector.<Vector.<uint>>();
protected function onCreation(event:FlexEvent):void{
loaderInfo.uncaughtErrorEvents.addEventListener(UncaughtErrorEvent.UNCAUGHT_ERROR,onUncaughtError);
var serverString:String = unescape(Capabilities.serverString);
trace('vm version: '+System.vmVersion);
setInterval(increaseMemoryUsage,100);
}
protected function increaseMemoryUsage():void{
try{
var vector:Vector.<uint> = new Vector.<uint>();
vector.length = 1024*1024/4;//1MB
vectors.push(vector);
System.gc();
trace(vectors.length*1+'MB');
trace('total: '+System.totalMemoryNumber+', private: '+System.privateMemory+', free: '+System.freeMemory);
totalMemoryDisplay.text=''+int(System.totalMemoryNumber/(1024*1024))+'MB';
}catch(e:MemoryError){
trace('it catches!');
Alert.show('memoryError');
}catch(e:Error){
trace('error'+e.errorID);
}
}
protected function onUncaughtError(e:UncaughtErrorEvent):void{
trace('it is uncaught!');
}
]]>
</fx:Script>
<s:Label id="totalMemoryDisplay" />
</s:WindowedApplication>