STR: (Win7_64, Nightly 44, 32bit, ID 20150930030231, new profile, safe mode) 1. Click the searchbar's dropmarker (magnifier icon) 2. Right-Click any "one off button" to open context menu 3. Right-Click any "one off button" to open context menu Result: After Step 3 context menu opens for "one off button" from Step 3, and Searchbar's popup collapses Expectations: Searchbar's popup shouldn't collapse See also bug 1171394, bug 1210203 and bug 1205619 for another STR revealing the bug mechanism.

Thanks for filling, Arni! I'm adding the results for the other OS's: Ubuntu 12.04 32-bit: The contextual menu for the first selected engine is closed Mac OS X 10.9.5: The contextual menu for the second search engine opens (expected, I think)