397206 - Partially loading a feed in a frame causes an error in FW_close (FeedWriter.js) and a leak

Status: RESOLVED WORKSFORME

(Firefox Graveyard :: RSS Discovery and Preview, defect)

Description

[Jesse Ruderman]

Attachment: testcase

Steps to reproduce:
1. Launch Firefox with XPCOM_MEM_LEAK_LOG=2
2. Load the testcase.
3. Wait about six seconds for it to finish.
4. Quit.

Result: 

while it's running:

JavaScript error: , line 0: uncaught exception: [Exception... "Component returned failure code: 0x80070057 (NS_ERROR_ILLEGAL_VALUE) [nsINavHistoryService.removeObserver]"  nsresult: "0x80070057 (NS_ERROR_ILLEGAL_VALUE)"  location: "JS frame :: file:///Users/jruderman/trunk/mozilla/debug-obj/dist/MinefieldDebug.app/Contents/MacOS/components/FeedWriter.js :: FW_close :: line 792"  data: no]

when you quit:

trace-refcnt complains about leaking BackstagePass, XPCWrappedNative, nsThread, nsSAXAttributes, etc.

Comment 1

[Jesse Ruderman]

Attachment: leak log

Comment 2

[Robert Sayre]

Attachment: trace of getElementById call

The exception in FW_Close is nothing to worry about, the FeedWriter is trying to remove itself as a history observer, but it never made it in because _initSubscriptionUI didn't succeed. It fails here:

<http://bonsai.mozilla.org/cvsblame.cgi?file=mozilla/browser/components/feeds/src/FeedWriter.js&rev=1.46#632>

> _initSubscriptionUI: function FW__initSubscriptionUI() {
>   var handlersMenuPopup = this._document.getElementById("handlersMenuPopup");

but wrapping this in a try/catch block doesn't catch the exception.

We're calling XPCWrappedNative::CallMethod even though the ccx claims that an exception is set (though the internal cx->throwing is false). See attached.

Comment 3

[Robert Sayre]

Bug 397225 fixes the errors here. 

However, the test leaks more stuff with that patch applied.

Comment 4

[Robert Sayre]

This looks like a leak related to XUL-in-XHTML, at least for the most part. I can get this to leak with all feed writing off by appending one XUL element to an XHTML div in the FeedWriter.init function. 

Comment 5

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

comment 0 talks about leaked nsSAXAttribute though, so that has to be related to the sax-parser or the feedwriter somehow, no? Or is that no longer the case with bug 397225 fixed?

Comment 6

[Jesse Ruderman]

Still leaks an nsSAXAttributes object.

Comment 7

[Mike Beltzner [:beltzner, not reading bugmail]]

Not blocking, but wanted if a fix presents itself.

Comment 8

[Jesse Ruderman]

Still leaks nsSAXAttributes on trunk.  (Feeds must be set to "preview in Firefox".)

Comment 9

[Jesse Ruderman]

Still leaks on mozilla-central (cd23e1bd82c4+).

Comment 10

[Jesse Ruderman]

Still leaks on mozilla-central.

Comment 11

[Jesse Ruderman]

WFM on trunk. No JS errors, no trace-refcnt leaks. (I had to increase 'max' in the testcase because the feed loads more slowly now.)