Affected builds: - Latest Nightly 40.0a1 Affected OS`s: - Windows 7 64-bit - Ubuntu 14.04 32-bit - Mac OS X 10.9.5 STR: 1. Start Firefox 2. Click Hello icon 3. Start a Conversation 4. Click 'Share Link' 5. Click 'Add a service' 6. Add 6 services 7. Click 'Share Link' 8. Add one more service 9. Click 'Share Link' Expected results: Dropdown does not change its size and is not overlapped. Actual results: At step 7 the top of the dropdown is hidden. At step 9 there are only 5 social services in focus (the rest are hidden but revealed by scrolling - expected) After each service that is added, clicking 'Share Link' will reveal less services caused by the dropdown resize. Notes: - Gif with the issue attached. - This is not a regression.

Also on Mac, there is some text overlapping when the scrollbar appears. See image from above.

Thanks for filing this, it does seem that the calculations are a bit off in some cases. I think the problem is that we're not yet taking the conversation toolbar into account. I do think that the situation as shown in the GIF is much better than it was before bug 1156205 landed, so we should keep it like this and treat this bug as an additional improvement.

Marking as WON'T FIX since we're removing the shareplane integration with bug 1178304 in 42.