home_url() $scheme parameter fails when site URL uses SSL

[johnbillion]

Steps to reproduce:

1. Go into General Settings and set your WordPress Address and Site Address to use SSL (eg. https://example.com).
2. Output a link somewhere using home_url() with the $scheme parameter set to 'http'. Example:

echo home_url( '/', 'http' );

Expected output: http://example.com.

Actual output: https://example.com.

The inverse of course works as expected, if your site uses an HTTP URL and you pass 'https' as the $scheme parameter you'll end up with https://example.com.

Seen in 3.3, probably occurs in earlier versions.

[johnbillion]

I'm going to close this as #20759 will address this issue by switching to the new set_url_scheme() function.