[Affected versions]: - Firefox 57beta9 - latest Nightly 58.0a1 [Affected platforms]: - Ubuntu 16.04 32/64bit [Unaffected platforms]: - Windows 10 - macOS 10.12.6 [Steps to reproduce]: 1. Start Firefox 2. Go to about:preferences#general 3. Scroll down to Applications 4. Click any Action (Preview in Nightly) [Expected result]: - The dropdown arrow is visible enough. [Actual result]: - The dropdown is barely visible, it looks like a small dot. [Regression range]: - This is a recent regression, here is the output from mozregression: Last good revision: f599f522b02ec1e7c4b7302ba8e31a716832b0c9 First bad revision: 8918870e7a2028ff664d553bb3c78e001160cf52 Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=f599f522b02ec1e7c4b7302ba8e31a716832b0c9&tochange=8918870e7a2028ff664d553bb3c78e001160cf52 Culprit 8918870e7a20 Evan Tseng — Bug 1398050 - Polish preferences page to match visual spec. r=mconley [Additional notes]: - Screenshot showing the issue attached.

Requesting needinfo from Evan since that bug caused this regression.

(In reply to Bogdan Maris, QA [:bogdan_maris] from comment #1) > Requesting needinfo from Evan since that bug caused this regression. Let me investigate this. Thank you.

Hi Mike, Could you help review the patch? And the screenshot[1] shows how it look like after applying the patch on Linux. [1]: https://bug1409640.bmoattachments.org/attachment.cgi?id=8922707

Comment on attachment 8922706 [details] Bug 1409640 - Remove menulist-dropmarker's margin top and bottom values in preferences.css then the smaller values (in common.css) will be applied since the space for the drop marker image is too small. https://reviewboard.mozilla.org/r/193874/#review198954

Pushed by rchien@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/0efc275f78e6 Remove menulist-dropmarker's margin top and bottom values in preferences.css then the smaller values (in common.css) will be applied since the space for the drop marker image is too small. r=dao

Verified that using latest Nightly 58.0a1 the issue is fixed for Ubuntu 16.04 64bit.

Comment on attachment 8922706 [details] Bug 1409640 - Remove menulist-dropmarker's margin top and bottom values in preferences.css then the smaller values (in common.css) will be applied since the space for the drop marker image is too small. Already got r+ from dao, so let's remove the mconley's review request.