Line number style changes depending on leading whitespace

[jg110]

There seem to be different line number styles used depending on leading whitespace. Here's an example from a test file in Text mode using solarized-dark:

Line number 1 has no styling applied, 2 (leading tab) is highlighted, and 3 (leading spaces) is italicized. This kind of styling only happens when both linum-mode and whitespace-mode are enabled, and doesn't happen in other themes. Here's the default theme (i.e. no theme loaded):

And manoj-dark:

[bbatsov]

Yeah, seems we've messed up some face definitions.