+++ This bug was initially created as a clone of Bug #644983 +++ STR: - install webtabs from http://jonathan.protzenko.free.fr/webtabs@momo.ca.xpi - open a twitter tab - switch to the main mail:3pane tab - select multiple threads (so that you get the MultiMessageSummary) - switch to the twitter tab - switch back to the main mail:3pane tab - click on one of your RSS feeds - there should be a message displayed ; instead, the message pane is blank, and the error console reads Error: window.top.content is null Source File: chrome://messenger/content/mailWindowOverlay.js Line: 3072 This happens *without* Thunderbird Conversations. Double-clicking on a feed item fixes the issue.

This patch: * Ports fix from TB bug * Matches position of early return with TB as comment in code suggests.

Comment on attachment 538245 [details] [diff] [review] Switch feed to use getBrowser [Checked in: Comment 4] I'm not an official MailNews reviewer, and don't know how to test the "broken" case, but feeds still seem to work with the patch applied, so f+ it is.

Comment on attachment 538245 [details] [diff] [review] Switch feed to use getBrowser [Checked in: Comment 4] Seems reasonable, although I think what's happening is that the Thunderbird conversations code must be messing with which browser is the active browser thus confusing the code that populates the content property. [Why do we still have code using XPCNativeWrapper?]

Comment on attachment 538245 [details] [diff] [review] Switch feed to use getBrowser [Checked in: Comment 4] http://hg.mozilla.org/comm-central/rev/172703bbcfee

Comment on attachment 538245 [details] [diff] [review] Switch feed to use getBrowser [Checked in: Comment 4] Thunderbird patch landed on comm-aurora.

Comment on attachment 538245 [details] [diff] [review] Switch feed to use getBrowser [Checked in: Comment 4] We probably want it on comm-beta too.

Pushed: http://hg.mozilla.org/releases/comm-aurora/rev/d586bcb76abd http://hg.mozilla.org/releases/comm-beta/rev/9ac9d52ebeff