User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b5pre) Gecko/20090517 Shiretoko/3.5b5pre Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1b5pre) Gecko/20090517 Shiretoko/3.5b5pre See test case and screen shots (coming). Reproducible: Always
Created attachment 379269 [details] Test case This page loads with the "drop down" button in the listbox hidden, until the selected option is changed.
Created attachment 379272 [details] Modified test case to work around the bug This test case has been slightly modified to include the Mozilla-specific "-moz-appearance" CSS property when setting the background color. This forces the drop down button to display properly.
Also effects Windows and OS X, and Firefox 3.0
This works fine for me with Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2a1pre) Gecko/20090522 Minefield/3.6a1pre I see a normal selectbox with dropdown arrow.
Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2a1pre) Gecko/20090525 Minefield/3.6a1pre Same result as Comment #2
Hmm. This is fun. The problem is that changing the background color triggers a repaint... but not a reflow. But changing it drops native theming, and the dropdown marker for combobox is hidden or shown during reflow depending on whether it's themed (on Mac and Linux, at least). So not a DOM issue at all; this is a pure layout problem. Fixing bug 393325 should help here; marking dependent and will retest once that's fixed.
I just hit this bug in the wild. 1) Goto: http://my.dot.tk/registration/availability?domainname=moz 2) Gasp at the price listed in the listbox. ;) 3) Hover your mouse over the listbox. Result: On hover, the same defect can be seen (the "down arrow button" is invisible). Selecting any other option in the listbox will make the button visible.