Selectmenu: Properly set width for button

[scottgonzalez]

Fixes #10145

I'm not sure why this test fails. I put the exact same code in a demo and it worked properly.

[tjvantoll]

The test doesn't work because the <select> in question already has a selectmenu instance associated with it. If you chain a selectmenu( "destroy" ) call before the selectmenu() one the test passes.

[scottgonzalez]

Ah, right. I thought I was using a different select than the other tests, but I ended up using the same one. This can be simplified a bit then :-)

[scottgonzalez]

updated

[tjvantoll]

You apparently commit faster than I type.

Besides that this seems fine. I hate having to show something to get its dimensions, but I don't think we have another choice here.

btw the second assertion in this test is the one that currently fails in IE 9–11, just in case looking into this has given you some insights into that mystery :)

[scottgonzalez]

Ok, I'll land this now and then try to figure out the existing failure.