895104 - Call to non-existent DOMRequestIpcHelper.observe

Status: RESOLVED FIXED

(Firefox OS Graveyard :: General, defect)

Description

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

Bug 889984 moved some DOMRequestIpcHelper code into DOMRequestIpcMessageListener, including observe().

SystemMessageManager.observe() still has a call

    this.__proto__.__proto__.observe.call(...)

which errors. cpeterson managed to hit this on Android. I'm surprised B2G hasn't been hit yet.

It seems to me this line should be removed. If I understand 889984 correctly, then it fixes the reason the line was added in bug 802564.

Comment 1

[Chris Peterson [:cpeterson]]

I hit an undefined `this.__proto__.__proto__.observe` when porting desktop system messages (bug 868322) to Android (bug 895689).

Comment 2

[Justin Lebar (not reading bugmail)]

I agree this line should go, but I'm confused as to why it's causing problems.  The observer service should swallow errors thrown when it calls observers, so if the observer service is the only one calling observe(), this exception shouldn't matter.

Is this line called from elsewhere?

If this causes problems, we should backport to b2g18, so please advise.

Comment 3

[Justin Lebar (not reading bugmail)]

Attachment: Patch, v1

Comment 4

[Justin Lebar (not reading bugmail)]

https://hg.mozilla.org/projects/birch/rev/7bb5b6909d3e

Comment 5

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/7bb5b6909d3e

Comment 6

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

Justin,
I'm not sure what the ni? here is for. observe() is being called manually in SystemMessageManager, and not through observer service, but I see your patch already understood and fixed that.

Comment 7

[Justin Lebar (not reading bugmail)]

Sorry to be unclear.

I'd like to know whether this line causes problems, or if it's just an innocuous error.  If it causes problems, we need to backport to b2g18.

AFAICT the error is innocuous, but I wanted to check.

Comment 8

[Gene Lian (I already quit Mozilla)]

That line is the last execution of SystemMessageManager.observe() so it won't stop any codes after that. I think it's innocuous. Keeping that only in central should be fine.

Comment 9

[Nikhil Marathe [:nsm] (No longer reading bugmail, please needinfo?)]

I'm going to go with Gene's judgement here, since I don't know the code that well.