iOS app crashes if a NetStream is referenced by a class variable when app is brought to foreground

[PippoApps]

Consistently happens on AIR 32 (tried also 27 and 31), iOS 12 and 8.

A video of this happening on both iOS8 and iOS12: airiosbug.mp4 - Google Drive

Just create a NetConnection and a NetStream.

If class has a variable referncing the NetStream, if app is brought to background and then to foreground, it crashes immediately.

If NetStrean is not referenced, app doesn't crash.

Crash log infact reports a null pointer.

Exception Type:  EXC_BAD_ACCESS (SIGSEGV)

Exception Subtype: KERN_INVALID_ADDRESS at 0x0000000000000000

Note that app works perfectly and for a long time if not brought to background and back to foreground again. Crashes only when brought back to foreground.

You can download source code here: https://drive.google.com/open?id=1s92-Wv99dechTZgqRxNMpf-C1SabxBNh

Here is the only code:

Commenting: "_ns = ns;" application does not crash.

package 
{
import flash.display.MovieClip;
import flash.net.NetConnection;
import flash.net.NetStream;
import flash.text.TextField;
/**
* ...
* @author Pippo Gregoretti
*/
public class MainAppDebug extends MovieClip 
{
private var _tf:TextField;
private var _ns:NetStream;   
public function MainAppDebug() 
{
super();
trace("Debugging AIR application.");
//(_debugConsole as DebugConsole).show();
_tf = new TextField();
_tf.border = true;
_tf.width = stage.stageWidth;
_tf.height = stage.stageHeight;
_tf.multiline = true;
addChild(_tf);
addText("Debugging AIR Application");
addText("Creating NetStreams...");
var nc:NetConnection = new NetConnection();
nc.connect(null);
var ns:NetStream = new NetStream(nc);
/* THIS IS THE CULPRIT. COMMENT "_ns = ns" AND APP WILL NOT CRASH */
_ns = ns;
}
private function addText(t:String):void {
_tf.appendText(t + "\n");
}
}
}

[PippoApps]

Here is the app descriptor:

<application xmlns="http://ns.adobe.com/air/application/32.0">

  <id>obscured</id>

  <versionNumber>0.4</versionNumber>

  <filename>AppName</filename>

  <description/>

  <name>AppName</name>

  <copyright/>

  <initialWindow>

   <content>AppName.swf</content>

   <systemChrome>standard</systemChrome>

   <transparent>false</transparent>

   <visible>true</visible>

   <fullScreen>true</fullScreen>

   <renderMode>direct</renderMode>

   <maximizable>true</maximizable>

   <minimizable>true</minimizable>

   <resizable>true</resizable>

   <autoOrients>true</autoOrients>

   <depthAndStencil>true</depthAndStencil>

   <aspectRatio>landscape</aspectRatio></initialWindow>

  <icon/>

  <customUpdateUI>false</customUpdateUI>

  <allowBrowserInvocation>false</allowBrowserInvocation>

  <supportedProfiles>desktop extendedDesktop mobileDevice extendedMobileDevice </supportedProfiles>

  <iPhone>

   <InfoAdditions><![CDATA[

  <key>UIDeviceFamily</key>

  <array>

  <string>1</string>

  <string>2</string>

  </array>

]]></InfoAdditions>

   <requestedDisplayResolution>high</requestedDisplayResolution>

  </iPhone>

  <supportedLanguages>en</supportedLanguages>

</application>

[Amrita Gangwani]

Hi,

Thank you for reporting the issueL The .libs and .src folders referenced by your application are missing in the above shared link. Please file a bug on Tracker​ and attach the complete source code for us to better understand the issue.

Thanks!

[PippoApps]

Hello Amrita,

Don't worry about libs and src, they are empty.

Just remove the references. Thank you.

Please check this issue since it makes Netstream unusable on Ios.

Regards

[PippoApps]

Dear Amrita,

The bug has been filed here: Tracker

Also another tester found the same issue, exactly with the code I have posted.

[PippoApps]

Dear Amrita,

Here is another version of source code with the 2 folder source references removed.

Please give attention to this bug since it's vital for any iOS appication playing a video.

https://drive.google.com/open?id=1V8cFQUyhPmQMuNQ1OKkVF5dfXrpY3lhc

Thank you very much

regards

Pippo

[PippoApps]

Hello,

any news on this?

It would be really appreciated if you could prioritise this since makes iOS user experience suffer.

Cheers

[zwetan_uk]

1st problem:
you pass a local variable nc:NetConnection by reference to a private class variable ns:NetStream

you have to define the nc var as a class variable too

2nd problem:
you do not use events, look at the example
NetConnection - Adobe ActionScript® 3 (AS3 ) API Reference

wait for a "NetConnection.Connect.Success" before creating your NetStream

potential other problems:
you define all your code into the constructor of the class
you do not listen for "Event.ADDED_TO_STAGE" before initializing your UI
you do not listen for "UncaughtErrorEvent.UNCAUGHT_ERROR"
etc.

It would be nice if you could
1) learn to provide a correct code sample to show if there is actually a bug
   what you provide above is like "made on purpose to fail"
2) do not consider Adobe support as your own personal debugging service
3) use all that as an excuse to criticize the prioritization of Adobe AIR iOS user experience

simply put if you have a bad experience it is because the code is sloppy at best
it got nothing to do with Adobe AIR

just copy/paste the default NetConnection example from the documentation pointed above

and you'll see it all work

[PippoApps]

Dear Zwetan,

the code posted here is super simplified in order to provide a clear example understandable at a glance.

If you prefer, I can post you the entire 800 lines of the centralized video player. Code is written in purpose to fail in order to identify a bug. If it didn't fail, how could they address it? Do not confuse Adonbe stuff, and try things out first please.

Does it seem ok to you that, on iOS only, recferencing a NetStream crashes the app if brought to background?

Do not confuse Adobe staff. This is a low level bug in iOS builds only, and should be fixed.

I assure you that:

- Initializing things after added to stage events it crashes anyway

- Listening to NetConnection connect event, it crashes anyway

- It doesn't crash on Mac, Windows and Android, but only iOS

Come on mate, I make a living deveoping high profile AS since the 90s, don't assume you are dealing with a noob. Besides you know me from other places (including your own AS3 forum). You do have a temper issue mate, this is not the first time.

Cheers mate.

And to Adobe staff, please test on your own iOS devices and you will see the bug.

[zwetan_uk]

that's not how it works

you don't submit 800 lines of code to support for them to sort out where is the bug
you, you do isolate where the bug occurs, and you make a code sample to explicitly prove that such thing is happening here

it has to be obvious
you make the code sample simple, easy to replicate, easy to compile

so support and other reviewers can easily run the code and confirm the bug

if you're unwilling to do that then don't expect anyone to look into your bug,

or expect it to be classified "for review later" or NAB ("not a bug") etc.

any amount of experience or years of programming have nothing to do with that

[PippoApps]

I try to follow you, but you are contradictory. There is a real nasty bug there, and I invested a lot of tim to isolate it to the bone in order not to be generic and give AIR staff the correct information without being verbose.

On your first comment you stated: "learn to provide a correct code sample to show if there is actually a bug   what you provide above is like "made on purpose to fail""

Then now you say: "you do isolate where the bug occurs, and you make a code sample to explicitly prove that such thing is happening here".

So, chose either one or the other.

I am not sure where your hostility comes from, but try to be supportive, this is a real bug that affects iOS so if you think you can contribute just do it, otherwise stop wasting your and my time.

[zwetan_uk]

I meant keep thing simple, but not too simple

the code from the first post is bad, just the part where you initialize everything in the constructor

code in constructor are not compiled/optimised the same that code in methods

in general any code in AS3 is JIT'ed, but not constructor functions
those generates $cinit calls that are always interpreted

not a big deal right?

except when you compile for iOS because there the code is AOT'ed

there is nothing interpreted ever under iOS because of Apple licensing

the compiler from the AIR SDK that take all this AS3 code

compile it to bytecode then cross-compile it to native code (only for iOS)
well... it will struggle more if you put "heavy" code in the constructor

but here the problem could be more complex than that

because in your constructor you not only init the UI code (TextField, etc.)
but also network code (NetConnection)
those have async parts,
can't draw the UI if the Event.ADDED_TO_STAGE did not occurs for some reason
can't wait for the network connection if the stage is not there because it block the main event loop
etc.

declaring all that code in the constructor and not using events is just asking for trouble
maybe it is not the cause of the crash you're experiencing

but it will certainly not help to clearly see what's going on

so what are ppl supposed to do?
take the sloppy code above and rewrite it cleanly for you ?

sorry no, you should do that

same for the gdrive BS, take your code sample to something like github
make it easy for others to get the code, comment about it, etc.

things like "don't worry about .libs and .src they are empty"
no, you worry about those

the sample should compile on first go from a build
no "you should remove this or add that for it to work" kind of manual intervention
that could make it work for some ppl or not for others

the more you automate it the more it is clear it is the same state for everyone

nobody 'want to spend few hours debugging something
for later some doofus telling you "oops I was careless, I forgot to ..."
or "well.... you should have done it in this order B before A, instead of A before B ..."
that is wasting everybody's time

same for the error you are reporting
you gave only 2 lines?
where is the full log? where is the stack trace?

you may think I'm too hard on you but really I'm not

developer time is precious, the shorter and faster you can give another dev

a set of very few steps to replicate your bug the faster he/she can validate it or not
if you make it harder it is most likely gonna end up in "I don't know", "we need more infos",
"let's look at it later" limbo

[PippoApps]

Zwetan plese vote for the bug on tracker.

Tracker

[PippoApps]

Dear Zwetan,

Since "developer time is precious", I am really moved by the effort you are putting in this. Thank you very much for your valuable contribution.

Just to let you know, I have been contacted by AIR staff, and they are working on a fix for this bug.

Probably your valuable effort in testing out on iOS and other platforms, and writing a better code gave then the hint they needed.

Regards

Pippo

[Rohit Guglani · Accepted solution]

Hello All,

We have done a AIR beta today, you can download it from Adobe AIR 32 Beta | application development - Adobe Labswhich contains the fix for this issue.

Regards,

Rohit

[PippoApps]

Thank you very much. I have tested and confirm this is fixed! You Rock!