Theme preview fails when Theme forlder contain "."(dot)

[supremecolor]

If the theme directory's name has dot(.) in it, the admin theme preview will show blank page.

for example, rename the default theme directory to "defau.lt", and click to preview the theme in admin area, it shows blank page.

Confirming this (with 2.6)

I'm not really sure why anyone would want to have a directory with a . in it, and I expect that there may be some security implications in it.

That said, since the theme itself works regardless of the . then the preview image should work, too.

Security? The exploit I can think of is '../../../to/public/folder/with/whatever/'. Periods are legal in folder names. '../' Should be stripped, not '.'.

[8485] and [8486]