Reproducible on: * Nightly 42.0a1 (2015-07-07) * Aurora 41.0a2 (2015-07-07) * Beta 40.0b2 (20150706172413) Affected platforms: * Microsoft Surface Pro 2 - Windows 10 Pro x64 (Insider Preview Build 10162) Steps to reproduce: 1. Enable "Table Mode" in Windows 10. 2. Launch Firefox. 3. Open the about dialog from menu → help → about firefox. 4. Drag & drop the browser window from the top to the left-hand side of the screen, to trigger side-by-side usage. Expected result: Any dialog box, window or tab originating from Firefox will respect the limitations set by the side-by-side view in Windows 10. Actual result: The dialog box is displayed on top of the side-by-side separator while Firefox is in focus.

Seems like all dialogs in Windows 10 touch mode are handled like this. This seems WONTFIX to me as this dialog would look fairly broken if it took the full screen height.

(In reply to Tim Nguyen [:ntim] from comment #1) > Seems like all dialogs in Windows 10 touch mode are handled like this. > This seems WONTFIX to me as this dialog would look fairly broken if it took > the full screen height. My reasoning here was that the about dialog should NOT pass beyond the separator displayed in side-by-side view.