docstring says "execute sitedir" - but that isn't what gets executed. 

suggested: 
    """Add a new path to known_paths by combining sitedir and 'name' 
or execute lines in name.pth that start with 'import'"""

site.py

def addpackage(sitedir, name, known_paths):

    """Add a new path to known_paths by combining sitedir and 'name' or execute sitedir if it starts with 'import'"""

    fullname = os.path.join(sitedir, name)
        f = open(fullname, "rU")
        for line in f:
            if line.startswith("import"):
                exec line
                                      

Here is a patch.  addpackage() is actually responsible
for .pth file processing, so the current docstring was
entirely incorrect.


File Added: addpackage_docstring.diff

Fixed in rev. 55455. (zseil, sorry, I didn't see your patch before committing it...)