406684 - Memory leaks when content policies set properties of wrapped nodes

Status: RESOLVED FIXED

(Core :: DOM: Core & HTML, defect, P2)

Description

[Wladimir Palant]

Attachment: Content policy for testing

This has been reported as a massive memory leak in the Adblock Plus extension when used with Minefield nightlies. After minimizing the testcase, it seems to be enough to do the following from a content policy (method ShouldLoad) on a wrapped content node:

    node.foo = 1;

Output from leak-gauge.pl after starting Minefield and closing it immediately after loading the first page:

Leaked inner window 16dc808 (outer 1811088) at address 16dc808.
 ... with URI "http://www.mozilla.org/projects/minefield/".
Leaked inner window 1662550 (outer 15e8530) at address 1662550.
 ... with URI "about:blank".
Leaked outer window 15e8530 at address 15e8530.
Leaked inner window 1890510 (outer 1811088) at address 1890510.
 ... with URI "about:blank".
Leaked outer window 1811088 at address 1811088.
Leaked document at address 16b7468.
 ... with URI "http://www.mozilla.org/projects/minefield/".
Leaked document at address 15bd9a0.
 ... with URI "about:blank".
Summary:
Leaked 5 out of 7 DOM Windows
Leaked 2 out of 38 documents
Leaked 0 out of 3 docshells

I didn't manage to reproduce the same issue without content policies though it might be possible. Regression range is 2007113005 to 2007120105, bug 348156 seems to be the only possible cause.

I am attaching a content policy for testing - download it into the components directory of your Minefield, make sure components are re-registered and enjoy the memory leak.

Comment 1

[Peter Van der Beken [:peterv]]

Attachment: v1

Comment 2

[Wladimir Palant]

Confirmed, no more leaks with 20071205 nightly build.