Relative links not being interpreted correctly

[GoogleCodeExporter]

weblar.org/blog/ uses a relative link to its blog feed ("/blog/feed"),
which FeedOnFeeds interprets oddly ("http:/blog/feed"), and as a result it
fails to update.  The particular error message I get on updating is also a
bit of a concern:

Updating weblar / kongbalong...
Warning: file_get_contents(http:/blog/feed/) [function.file-get-contents]:
failed to open stream: No such file or directory in [my server
path]/fonf/simplepie/simplepie.inc on line 6656
Error: file_get_contents could not read the file try to validate it? 

Even if I manually point FonF to the RSS feed directly, the feed location
gets clobbered every time it updates.  It seems that FonF is attempting to
re-autodiscover the feed location every time, which ends up breaking on
several sites which provide RSS separately from the content (such as
comics.com).

Original issue reported on code.google.com by fluffy%[email protected] on 6 May 2009 at 3:47