bug#11981: 24.1.50; url-http-parse-headers should not disable file name handlers since it breaks auth-source

[David Engster]

David Engster writes:
> Stefan Monnier writes:
>>>> However, this workaraound assumes that everything that gets afterwards
>>>> in the `let'-section does not depend on file name handlers. However,
>>>> this is not the case: `url-http-handle-authentication' is called which
>
>>>> in turn calls the auth-source package. This package however supports
>>>> encrypted authinfo files which have to be automatically decrypted
>>>> through `auto-encryption-mode'. This, of course, works through file name
>>>> handlers.
>>> Does it work, if Tramp is disabled instead?
>>
>> I think I'd first like to better understand bug#6717: why do we take
>> a local part of a URL, let it start with / and then pass it to
>> file-name-directory?  That sounds like a problem in itself.
>
> I agree. I wonder which call to `file-name-directory' threw the error in
> the original report - the most likely candidate is `url-file-directory',
> which should simply be rewritten to not use `file-name-directory'.

Patch attached. It even fixes another bug along the way:
`url-file-(non)directory' would not work on hexified URLs.

I'm not 100% sure this also fixes bug #6717; it might be that there's
another file-* call lurking somewhere.

-David

=== modified file 'lisp/url/url-util.el'
--- lisp/url/url-util.el        2012-07-11 23:13:41 +0000
+++ lisp/url/url-util.el        2012-07-21 14:25:59 +0000
@@ -246,18 +246,24 @@
   "Return the directory part of FILE, for a URL."
   (cond
    ((null file) "")
-   ((string-match "\\?" file)
-    (file-name-directory (substring file 0 (match-beginning 0))))
-   (t (file-name-directory file))))
+   ((string-match "\\(\\?\\|%3[fF]\\)" file)
+    (url-file-directory (substring file 0 (match-beginning 0))))
+   ((string-match "\\(.*\\(/\\|%2[fF]\\)\\)" file)
+    (match-string 1 file))
+   (t
+    "")))
 
 ;;;###autoload
 (defun url-file-nondirectory (file)
   "Return the nondirectory part of FILE, for a URL."
   (cond
    ((null file) "")
-   ((string-match "\\?" file)
-    (file-name-nondirectory (substring file 0 (match-beginning 0))))
-   (t (file-name-nondirectory file))))
+   ((string-match "\\(\\?\\|%3[fF]\\)" file)
+    (url-file-nondirectory (substring file 0 (match-beginning 0))))
+   ((string-match ".*\\(?:/\\|%2[fF]\\)\\(.*\\)" file)
+    (match-string 1 file))
+   (t
+    "")))
 
 ;;;###autoload
 (defun url-parse-query-string (query &optional downcase allow-newlines)