648856 - Broken sessionstore.js causing pages to appear blank on startup

Status: RESOLVED INVALID

(Firefox :: Session Restore, defect)

Description

[Paul Lammertsma]

User-Agent:       Mozilla/5.0 (Windows NT 6.0; rv:2.0) Gecko/20100101 Firefox/4.0
Build Identifier: Mozilla/5.0 (Windows NT 6.0; rv:2.0) Gecko/20100101 Firefox/4.0

Firefox was closed while in Private Browsing mode. After reopening it, I noticed that all my tabs appeared as blank pages, and that I needed to reload them manually.

Curious if this was related to Private Browsing, I tried switching to that mode again. Nothing appeared to happen, so I pressed it again. Now, my two pinned tabs became unpinned, but otherwise, again, no effect. A third press finally brought me to Private Browsing.

I stopped Private Browsing, which immediately brought all my tabs back.

Now, every time that I start Firefox, my tabs appear blank. I have resolved this by renaming my sessionstore.js, which appears to have somehow become corrupted. I have a backup of this file if that is useful for debugging the problem, but it contains login tokens to work-related websites.

I would be happy to attach the file if anybody can tell me how to strip this information.

To give a clue: the sessionstore.js is very large (700kb) and contains 1 tab item with 50 entries, each with about 5 children. The impression I get when switching to Private Browsing is that the windows are somehow internally stacked, and that Firefox is opening the pages on top of each other, so to speak.

Reproducible: Didn't try

Steps to Reproduce:
1. Start Private Browsing
2. Exit Firefox
3. Start Firefox
Actual Results:  
All tabs are blank. Switching back to Private Browsing takes several attempts, between which tabs appear to jump.

Expected Results:  
Pages reload and show content. Switching back to Private Browsing is instantaneous.

If you want me to do some testing with the sessionstore.js, I'd be happy to comply. I can also try this in Fx 4.2a1.

Comment 1

[Paul Lammertsma]

I have just tried loading the sessionstore.js in Fx 4.2a1, and cannot reproduce the behavior. The file remains very large, however.

Pushing it back into Fx 4.0 produces the behavior as described in the report. It took me about six or seven tries to get to Private Browsing mode. The only noteworthy change while hitting Private Browsing mode was that pinned tabs toggled their states twice.

Comment 2

[Paul Lammertsma]

Attachment: Example of broken sessionstore.js

I've removed all identifiable information and set the URLs to google.com. When I load Firefox with this sessionstore.js, only a few of the pages actually reload (the others display the title "--STRIPPED-TITLE--" from the file).

Trying to switch to Private Browsing again causes the pinned tabs to unpin, and only actually switches to Private Browsing after a few attempts.

Comment 3

[Paul O'Shannessy [:zpao] (not bugmail, email directly)]

(In reply to comment #2)
> Created attachment 524951 [details]
> Example of broken sessionstore.js
> 
> I've removed all identifiable information and set the URLs to google.com. When
> I load Firefox with this sessionstore.js, only a few of the pages actually
> reload (the others display the title "--STRIPPED-TITLE--" from the file).
> 
> Trying to switch to Private Browsing again causes the pinned tabs to unpin, and
> only actually switches to Private Browsing after a few attempts.

Everything worked here with a (mostly) new profile. Do you have any extensions or something that could be interfering?

Comment 4

[Paul Lammertsma]

Wow, I can't believe I overlooked checking that. Starting in safe mode works perfectly.

I pinpointed exactly which add-on is causing this (Session History Tree) and will refer the author to this bug report. Thanks for testing, Paul.

Comment 5

[Paul O'Shannessy [:zpao] (not bugmail, email directly)]

No problem. I don't like to see bugs in add-ons, but at least it's not Firefox :)