Container tabs are not being restored correctly when using the "Show my windows and tabs from last time" feature under about:preferences#general. I've noticed that sometimes the container tabs are not restored and the following error message is displayed via the terminal/browser console: ************************* A coding exception was thrown in a Promise resolution callback. See https://developer.mozilla.org/Mozilla/JavaScript_code_modules/Promise.jsm/Promise Full message: TypeError: this._identities.find is not a function Full stack: getIdentityFromId@resource://gre/modules/ContextualIdentityService.jsm:248:25 setTabStyle@resource://gre/modules/ContextualIdentityService.jsm:277:20 addTab@chrome://browser/content/tabbrowser.xml:1990:15 ssi_restoreWindow@resource:///modules/sessionstore/SessionStore.jsm:2958:33 ssi_restoreWindows@resource:///modules/sessionstore/SessionStore.jsm:3144:5 initializeWindow@resource:///modules/sessionstore/SessionStore.jsm:1046:11 SessionStoreInternal.onBeforeBrowserWindowShown/<@resource:///modules/sessionstore/SessionStore.jsm:1201:9 Handler.prototype.process@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:937:23 this.PromiseWalker.walkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:816:7 Promise*this.PromiseWalker.scheduleWalkerLoop@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:747:11 this.PromiseWalker.schedulePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:779:7 this.PromiseWalker.completePromise@resource://gre/modules/Promise.jsm -> resource://gre/modules/Promise-backend.js:714:7 onSuccess@resource://gre/modules/osfile/osfile_native.jsm:63:7 ************************* I attempted to get a regression range with mozregression, but it seems tricky to get it working with session restores. I'll attach a regression range once I figure out how to reproduce it while using mozregression. STR: (https://youtu.be/DsJND6NOqMg) * install/open the latest version of m-c * change "When Nightly starts" under about:preferences#general to "Show my windows and tabs from last time" * close the about:preferences#general tab * open a personal and work container via File -> New Container Tab * close/restart m-c (if it restores the tabs correctly the first time around, close/restart m-c a few more times)

good 2016-06-14 bad 2016-06-15 change log: https://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=ddb6b30149221f00eb5dd180530e9033093d4c2b&tochange=14c5bf11d37b9e92d27f7089d9392de2ac339bb3

This will be resolved by the work in Bug 1291524

As per bug#1291524 comment#12, this issue also affects fx50.

I don't see container tab options in the latest dev edition (50) build. Do you, Kamil? Maybe it's something that's been set in a profile you used when 50 was nightly?

(In reply to Andrew Overholt [:overholt] from comment #4) > I don't see container tab options in the latest dev edition (50) build. Do > you, Kamil? Maybe it's something that's been set in a profile you used when > 50 was nightly? The container feature has been in the m-a channel for some time now, however, it's disabled by default and is behind the "privacy.userContext.enabled" pref. To reproduce this, you'll need: * privacy.userContext.enabled;true ("New Container Tab" context menu should appear under "File") * follow the original STR from comment#0

Ok, then I'm not sure how much we care about this regression since preffed off things are, well, preffed off :)

I marked this as disabled in 51 since containers aren't shipping by default there.

Kamil, please see if this is still valid or we can close duplicate of Bug 1291524.

As per comment#2, this has been resolved by the work that was completed in Bug#1291524. Loaded/logged into several websites using containers and went through the following test cases: * History -> Restore Previous Session * Hamburger Menu -> History -> Restore Previous Session * about:home -> "Restore Previous Session" * about:preferences#general -> "Show my windows and tabs from last time" * went through the original STR from comment#0 Platforms Used: * macOS 10.12.2 x64 - PASSED * Win 10 x64 - PASSED Used the following builds: * https://archive.mozilla.org/pub/firefox/nightly/2016/12/2016-12-19-03-02-07-mozilla-central/ * https://archive.mozilla.org/pub/firefox/nightly/2016/12/2016-12-19-00-40-24-mozilla-aurora/ * https://archive.mozilla.org/pub/firefox/candidates/51.0b8-candidates/build1/