[Note]: - Logged bug based on Bug 1241326 Comment 23 [Affected versions]: - Firefox 47.0a1 (2016-02-21) [Affected platforms]: - Windows 10 x86, Ubuntu 14.04 x86, Mac OS X 10.9.5 [Steps to reproduce]: 1. Launch Firefox. 2. From about:config, enable the devtools.responsive.html.enabled pref. 3. Open RDM. 4. Enlarge the viewport horizontally. 5. Click on the Landscape/Portrait button that rotates the viewport and look out for the grippers(see http://screencast.com/t/2e7ZrMV8y). [Expected result]: - The grippers are accessible. [Actual result]: - The grippers are not accessible. [Regression range]: - This is not a regression since this is a new implementation.

Another issue is that if the Height input is a big no.(e.g. 2000), the viewport can't be scrolled in order to see the width / height inputs area. This are can be accessed if only the Tab key is used, case in which the top part of the viewport is not accessible. Commented based on Bug 1246807 Comment 15.

Note that the RDM in google chrome deals with this by zooming out the viewport area. If you enter a height of 2000px and it turns out this height doesn't fit in your browser window, then the whole viewport is scaled accordingly so that it fits. The zoom value is also displayed in their toolbar and is editable.

I'm marking this bug Verified fixed, since is no longer reproducible on Firefox 52.0 RC build. The bug was verified under Mac OS X 10.11.6, Ubuntu 16.04x64, Windows 10x64.

Hmm, I guess we're now scrolling the RDM UI, so you can reach grippers of a very tall viewport. Not sure it will stay that way, but it is a least a workaround for this precise issue.