Created attachment 8751867 [details] Screen Shot 2016-05-09 at 3.22.55 PM.png User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_4) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/50.0.2661.94 Safari/537.36 Steps to reproduce: Message create window on secondary (external) monitor - click any of the buttons that initiate a popup dialog (add link, add image, select colour) Actual results: Popup dialog is mis-sized so that only the upper left part of the dialog is visible. Dragging the entire composition window to the primary monitor does not correct the sizing error. However, if the composition window is dragged to the primary monitor *before* the button is clicked, the sizing is correct, and the entire composition window can be dragged to the secondary monitor with no corruption. Expected results: Popup dialog should have been correctly sized regardless of being on the external monitor.
This problem was originally reported under bug 1266354 against TB 45.0. When that bug was fixed in 45.1, this problem remained. Since the code is largely shared with Firefox, I did try to reproduce the same issue in FX 45, and was unable to do so. I tried various dialogs in Preferences->Advanced that appeared to have similar implementations (Network->Connection->Settings, Update->Show Update History for example), and no similar sizing problem occurred. But since I don't know for sure whether these dialogs actually use similar code, I can't be absolutely sure that the problem doesn't occur elsewhere in FX 45.
Glenn, can you please report exactly what version of Firefox you are using to test? yes you said 45.0, it that correct, and if so is is the esr version, or an older release. (current firefox is 46.0.1).
Apologies - I tested on the current 46.0.1 release - I hadn't noticed that it had updated. I can test again against a different version if I can get hold of it.
I just tested against 45.0.2 - same things in Preferences->Advanced - still no sizing issues on external monitor. Is there a different release you'd like me to test against?
The reality is that we are not going to be able to locate any secondary monitor issues, other than trying to find the appropriate Mozilla code patch and uplift it (like we did for bug 1266354). I'm also not sure if testing is going to help. The previous patch was suggested by people familiar with the graphics code. It will be interesting to see if later versions of Thunderbird still have this, as there has been a lot of changes in the graphics code (which makes uplifts hard as well). So you might check with the latest test builds of Thunderbird, aurora (Early Bird) and central (Daily) and see if they exhibit the problem. But really the key to fixing this is going to be reproducing in Firefox.
You need to log in before you can comment on or make changes to this bug.