Since between version 10.0.2 and 11.0.1 separators in the header pane toolbar have not been visible anymore. If you add a separator to the header pane toolbar (by using the customization drop down menu over the toolbar), the separator is not visible in the toolbar and it can't be removed anymore (other then by selecting default set). Instead an empty space is added to the toolbar. Actually, (nearly) the same applies to the "space" button: After adding it to the header pane toolbar it cannot be removed anymore. It worked with version 10.0.2 and does not work with 11.0.1. The problem still exists in the trunk.
Is this a theme or actual toolbar/XUL-implementation problem?
Which platform? Mac has always been 1px wide...
I see this on XP. I'll check this evening if it also happens on Win7 and Linux. Mark, the problem is the separator has a height of 0px. If you see the separator on OSX then OSX isn't affected by this problem.
Same on Linux, it's impossible get the "hand" cursor over a separator when customizing the message-header toolbar.
I see the problem on Windows 7
Created attachment 665069 [details] [diff] [review] patch I checked also under OSX and the separator isn't visible. Adding the height make it visible. On main toolbar the separator is still stretched to full height.
Comment on attachment 665069 [details] [diff] [review] patch This seems to fix the problem, so ui-r=me. And the code seems fine, too, so r=me. Thanks, Blake.
Comment on attachment 665069 [details] [diff] [review] patch [Approval Request Comment] It's only a small CSS patch which could make user's life easier. But it's not so important when it doesn't land as it took 5 versions until the bug is found.