Bug 640147 introduced a new method to folderDisplay.js, canArchiveSelectedMessages(). Unfortunatly this breaks the context menu if called on a feed (RSS) message: Error: TypeError: GetIdentityForHeader(...) is null Source File: chrome://messenger/content/folderDisplay.js Line: 89 The solution is to port TB bug 912183: return this.selectedMessages.every(function(msg) { - return getIdentityForHeader(msg).archiveEnabled; + let identity = getIdentityForHeader(msg); + return Boolean(identity && identity.archiveEnabled); }); Note: Our function is called GetIdentityForHeader, not getIdentityForHeader. Will provide a patch later today.

(In reply to Jens Hatlak) > return this.selectedMessages.every(function(msg) { > - return getIdentityForHeader(msg).archiveEnabled; > + let identity = getIdentityForHeader(msg); > + return Boolean(identity && identity.archiveEnabled); > }); [Why bother with the Boolean cast in a boolean evaluation context?]

(In reply to neil@parkwaycc.co.uk from comment #1) > (In reply to Jens Hatlak) >> + return Boolean(identity && identity.archiveEnabled); > [Why bother with the Boolean cast in a boolean evaluation context?] I notice that Magnus likes to use this idiom (The Thunerbird patch was written by Magus).

[Approval Request Comment] Regression caused by (bug #): bug 640147 User impact if declined: MailNews message context menu sometimes broken Testing completed (on m-c, etc.): locally Risk to taking this patch (and alternatives if risky): low String changes made by this patch: none

Comment on attachment 8347289 [details] [diff] [review] patch Note: not actually tested, but looks sane. [As a side note, this function must be incredibly inefficient if you have a large number of messages selected, no?]

Comment on attachment 8347289 [details] [diff] [review] patch https://hg.mozilla.org/comm-central/rev/2d3862e59d33 (In reply to neil@parkwaycc.co.uk from comment #4) > Note: not actually tested, but looks sane. Don't you worry, I tested. > [As a side note, this function must be incredibly inefficient if you have a > large number of messages selected, no?] Probably. I guess it could/should be optimized quite a bit for when only a certain account is affected or the like, but then there's saved searches, which can affect multiple accounts of different types, and we must not regress those. So better have an own bug for such complicated matters.

Comment on attachment 8347289 [details] [diff] [review] patch a=me for aurora and beta.

Comment on attachment 8347289 [details] [diff] [review] patch https://hg.mozilla.org/releases/comm-aurora/rev/9753a7ca30b4 https://hg.mozilla.org/releases/comm-beta/rev/8adf90b209c1