When Firefox (or Thunderbird) is in offline mode, going into the Help->About dialog still shows the "check for updates" button (or checks automatically). The network is not hit therefore no updates are found and the message says FF (or TB) is up to date (which may not be true). I was hit by this in some test profiles where I wanted to be in permanent offline mode (but already forgot I have set it in the past), but still wanted nightly updates. The message misled me into thinking there really weren't any updates. Expected results: Choose any solution out of: 1. no button or automatic check. Instead a message the program is in offline mode in its place. 2. or allow to run check but return "the program is in offline mode" instead "program is up to date".

The code for the about dialog is application specific and will need to be fixed for each application individually. Moving this to Firefox -> General and a new bug will need to be filed for Thunderbird.

duplicate of bug 803202?

I think that bug is fairly different. Aryx, are you actually working on this?

(In reply to Wayne Mery (:wsmwk) from comment #2) > duplicate of bug 803202? This is a different bug and will need to be handled in Firefox's about dialog (the app update UI already reports this) or it will be handled by Firefox using the widget being developed in bug 599574 which likely won't be finished for a while.

(In reply to :aceman from comment #0) > When Firefox (or Thunderbird) is in offline mode, going into the Help->About > dialog still shows the "check for updates" button (or checks automatically). > The network is not hit therefore no updates are found and the message says > FF (or TB) is up to date (which may not be true). The same thing happens when there is no internet connection at all (i.e. it’s not specific to the Firefox “Work Offline” mode) or when an non-functioning proxy has been configured through Firefox → Preferences → Network → Settings.

Yes, but I'd consider that less serious. The button is there, user clicks it, THEN Firefox attempts to contact server and find out network is not working. Yes, it should say network down, not "your firefox is up to date". On the other hand, if user intentionally put TB/FF into offline mode, the app knows beforehand it has no sense to display the button as the check can't ever succeed. That is the bug being reported here.

(In reply to Mathias Bynens from comment #6) > The same thing happens when there is no internet connection at all Bug 1017817 was about that, but it's considered intentional behavior.