776375 - Shutdown crash with mozCaptureStreamUntilEnded

Status: RESOLVED INCOMPLETE

(Core :: Audio/Video: MediaStreamGraph, defect)

Description

[Jesse Ruderman]

Attachment: testcase (causes a shutdown crash)

1. Load the testcase
2. Reload a few times, maybe
3. Quit Firefox

Result: crash during cycle collection, with mozilla::MediaStreamGraphImpl::AppendMessage on the stack.

Comment 1

[Jesse Ruderman]

Attachment: stack trace (gdb)

Nightly: bp-443e32de-229d-4bca-b5b8-768ec2120722

Comment 2

[Jesse Ruderman]

Attachment: stack trace (minidump_stackwalk)

Comment 3

[Jesse Ruderman]

Maybe this is just a null deref, and I'm missing symbols for part of libxul??

Comment 4

[Randell Jesup [:jesup] (needinfo me)]

GDB stack trace:
1693	      mStream->DestroyImpl();
(gdb) bt
#0  0x000000010231132e in UpdateAffectedStream (this=0x10e6a8610) at /Users/jruderman/trees/mozilla-central/content/media/MediaStreamGraph.cpp:1693
#1  0x0000000102311376 in ProcessDuringShutdown (this=0x10e6a8610) at /Users/jruderman/trees/mozilla-central/content/media/MediaStreamGraph.cpp:1697

This certainly looks like a null deref there (of mStream, perhaps).  Not sure why the minidump stackwalk wouldn't pick it up.

A null check can be added to MediaStream::Destroy()'s UpdateAffectedStream(), though I'd like to know or solve why that happens, unless it's expected.

Comment 5

[Randell Jesup [:jesup] (needinfo me)]

We should retest this, since this code has mutated so much since it was filed.  Very likely this is no longer relevant.  Moving to unconfirmed to indicate this

Comment 6

[Maire Reavy [:mreavy]]

I really believe this is no longer happening.  If it is, please reopen.