The new message reader pane (bug 449691) broke the option to show message references, which was introduced by bug 62033. Bug 62033 added the pref mailnews.headers.showReferences. When set to true, it displays the References header for emails. For newsgroup postings, the header was displayed regardless of the pref. It's most useful if the referenced message is in another folder (like Sent/Inbox) or another newsgroup.

This is just a backout of the relevant part of bug 449691: http://hg.mozilla.org/comm-central/rev/bc29303430f4#l3.1 It always shows the References header for newsgroup postings. It's hidden by default for emails, but can be made visible by setting mailnews.headers.showReferences to true.

I can understand wanting to add the references header back in, but why the Sender as well? You haven't explained that.

Comment on attachment 366119 [details] [diff] [review] patch I haven't tested yet, as waiting for explaination re the sender option. Therefore canceling review request for now, please re-request when you explain the sending option.

Right, I was misled by the XXX comment and the pref. With the first patch, the sender header would be shown whenever Sender != From. That's often the case for automated emails like like newsletters. I don't like that extra header, so I'm commenting it out. But If we are to ditch the ability to show the sender header entirely, there's a lot more code to remove. I'm removing the "extraExpandedHeaderList" array and the showSender pref since they're unused. So this patch just reenables the option to show message references.

I don't think we want to ditch that option, but why are you removing it (mailnews.headers.showSender) from mailnews.js?

Because the showSender pref is not used at at all: http://mxr.mozilla.org/comm-central/search?string=showSender If we want to make the display of the sender header configurable, we need additional code which actually checks that pref. If/when we add such code, we can reintroduce the pref as well.

OK, this fixes the Sender header as well. Both headers are not displayed by default; you need to set mailnews.headers.showReferences and/or mailnews.headers.showSender to true. The latter also requires a restart.

Comment on attachment 367434 [details] [diff] [review] patch v2: fix Sender header as well r=me subject to Bryan's ui-review. Bryan, (just so it is clear) this patch: - Adds back the option via hidden pref to display the "Sender" message header in the expanded header view. - Re-enables the references number/menu display in newsgroups so that it is always displayed (I've got a feeling this was intentionally removed?). - Adds back the hidden preference option to display references on any email in the expanded header view.

Comment on attachment 367434 [details] [diff] [review] patch v2: fix Sender header as well Ok, sounds good. Thanks for the explanation Mark!

Fixed: http://hg.mozilla.org/comm-central/rev/dfb93816a016 Also tweaked the summary per comment 8.