bug in url.el

bug in url.el

[ken]

Some code developed a few years ago which worked fine up to my latest 
upgrade of emacs now errors out with:

Debugger entered--Lisp error: (void-variable url-passwd-entry-func)
   (cond (url-passwd-entry-func nil) ((fboundp ...) (setq 
url-passwd-entry-func ...)) ((or ... ...) (if ... ...) (setq 
url-passwd-entry-func ...)) ((or ... ...) (setq url-passwd-entry-func 
...)) (t (url-warn ... "(url-setup): Can't determine how to read 
passwords, winging it.")))
   (if url-setup-done nil (mailcap-parse-mailcaps) 
(mailcap-parse-mimetypes) (url-register-auth-scheme "basic" nil 4) 
(url-register-auth-scheme "digest" nil 7) (setq url-cookie-file (or 
url-cookie-file ...)) (setq url-history-file (or url-history-file ...)) 
(url-history-parse-history) (url-history-setup-save-timer) 
(url-cookie-setup-save-timer) (url-cookie-parse-file url-cookie-file) 
(let (...) (if noproxy ...)) (cond (url-passwd-entry-func nil) (... ...) 
(... ... ...) (... ...) (t ...)) (url-setup-privacy-info) (run-hooks 
(quote url-load-hook)) (setq url-setup-done t))
   (unless url-setup-done (mailcap-parse-mailcaps) 
(mailcap-parse-mimetypes) (url-register-auth-scheme "basic" nil 4) 
(url-register-auth-scheme "digest" nil 7) (setq url-cookie-file (or 
url-cookie-file ...)) (setq url-history-file (or url-history-file ...)) 
(url-history-parse-history) (url-history-setup-save-timer) 
(url-cookie-setup-save-timer) (url-cookie-parse-file url-cookie-file) 
(let (...) (if noproxy ...)) (cond (url-passwd-entry-func nil) (... ...) 
(... ... ...) (... ...) (t ...)) (url-setup-privacy-info) (run-hooks 
(quote url-load-hook)) (setq url-setup-done t))
   url-do-setup()
   url-retrieve("....

The URL my code is trying to fetch requires no password, so that's the 
first odd thing.  Why should the function fail for lack of something 
which isn't needed?  Whatever password configuration the function is 
requiring should be required only when the situation requires it, yes? 
So I'd think that portion of the code should be moved out from 
url-do-setup and called only when needed, i.e., only when the URL 
requires a userid and password.

The same function makes mention of 'user defaults' but gives not a hint 
as to how the user is to set such defaults.  It would seem to be a good 
idea for this information to be provided somewhere so that regular users 
can set their defaults without having to reverse engineer the code to 
see what's being asked for.

Finally, what could I easily and expediently do to work around this bug? 
  My first thought would be to put some statements and/or assign some 
variables in the user defaults file, whatever and wherever that is and 
in whatever format this function would accept.  But other workarounds 
might be  better... who knows?

tia.

bug in url.el

[ken]

[-- Attachment #1: Type: text/plain, Size: 2788 bytes --]

Some code developed a few years ago which worked fine up to my last 
upgrade of emacs now errors out with:

Debugger entered--Lisp error: (void-variable url-passwd-entry-func)
   (cond (url-passwd-entry-func nil) ((fboundp ...) (setq 
url-passwd-entry-func ...)) ((or ... ...) (if ... ...) (setq 
url-passwd-entry-func ...)) ((or ... ...) (setq url-passwd-entry-func 
...)) (t (url-warn ... "(url-setup): Can't determine how to read 
passwords, winging it.")))
   (if url-setup-done nil (mailcap-parse-mailcaps) 
(mailcap-parse-mimetypes) (url-register-auth-scheme "basic" nil 4) 
(url-register-auth-scheme "digest" nil 7) (setq url-cookie-file (or 
url-cookie-file ...)) (setq url-history-file (or url-history-file ...)) 
(url-history-parse-history) (url-history-setup-save-timer) 
(url-cookie-setup-save-timer) (url-cookie-parse-file url-cookie-file) 
(let (...) (if noproxy ...)) (cond (url-passwd-entry-func nil) (... ...) 
(... ... ...) (... ...) (t ...)) (url-setup-privacy-info) (run-hooks 
(quote url-load-hook)) (setq url-setup-done t))
   (unless url-setup-done (mailcap-parse-mailcaps) 
(mailcap-parse-mimetypes) (url-register-auth-scheme "basic" nil 4) 
(url-register-auth-scheme "digest" nil 7) (setq url-cookie-file (or 
url-cookie-file ...)) (setq url-history-file (or url-history-file ...)) 
(url-history-parse-history) (url-history-setup-save-timer) 
(url-cookie-setup-save-timer) (url-cookie-parse-file url-cookie-file) 
(let (...) (if noproxy ...)) (cond (url-passwd-entry-func nil) (... ...) 
(... ... ...) (... ...) (t ...)) (url-setup-privacy-info) (run-hooks 
(quote url-load-hook)) (setq url-setup-done t))
   url-do-setup()
   url-retrieve("....

See url.el attached.

The URL my code is trying to fetch requires no password, so that's the 
first odd thing.  Why should the function fail for lack of something 
which isn't needed?  Whatever password configuration the function is 
requiring should be required only when the situation requires it, yes? 
So I'd think that portion of the code should be moved out from 
url-do-setup and called only when needed, i.e., only when the URL 
requires a userid and password.

The same function makes mention of 'user defaults' but gives not a hint 
as to how the user is to set such defaults.  It would seem to be a good 
idea for this information to be provided somewhere so that regular users 
can set their defaults without having to reverse engineer the code to 
see what's being asked for.

Finally, what could I easily and expediently do to work around this bug? 
  My first thought would be to put some statements and/or assign some 
variables in the user defaults file, whatever and wherever that is and 
in whatever format this function would accept.  But other workarounds 
might be  better... who knows?

tia.


[-- Attachment #2: url.el --]
[-- Type: text/plain, Size: 9677 bytes --]

;;; url.el --- Uniform Resource Locator retrieval tool
;; Author: Bill Perry <wmperry@gnu.org>
;; Version: $Revision: 1.15 $
;; Keywords: comm, data, processes, hypermedia

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Copyright (c) 1993 - 1996 by William M. Perry <wmperry@cs.indiana.edu>
;;; Copyright (c) 1996, 97, 98, 99, 2001 Free Software Foundation, Inc.
;;;
;;; This file is part of GNU Emacs.
;;;
;;; GNU Emacs is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2, or (at your option)
;;; any later version.
;;;
;;; GNU Emacs is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with GNU Emacs; see the file COPYING.  If not, write to the
;;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;;; Boston, MA 02111-1307, USA.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

;; Registered URI schemes: http://www.iana.org/assignments/uri-schemes

(eval-when-compile (require 'cl))
;; Don't require CL at runtime if we can avoid it (Emacs 21).
;; Otherwise we need it for hashing functions.  `puthash' was never
;; defined in the Emacs 20 cl.el for some reason.
(if (fboundp 'puthash)
    nil					; internal or CL is loaded
  (defalias 'puthash 'cl-puthash)
  (autoload 'cl-puthash "cl")
  (autoload 'gethash "cl")
  (autoload 'maphash "cl")
  (autoload 'make-hash-table "cl"))

(eval-when-compile
  (require 'mm-decode)
  (require 'mm-view))

(require 'mailcap)
(require 'url-vars)
(require 'url-cookie)
(require 'url-history)
(require 'url-expand)
(require 'url-privacy)
(require 'url-methods)
(require 'url-proxy)
(require 'url-parse)
(require 'url-util)

;; Fixme: customize? convert-standard-filename? 
;;;###autoload
(defvar url-configuration-directory "~/.url")

(defun url-do-setup ()
  "Setup the url package.
This is to avoid conflict with user settings if URL is dumped with
Emacs."
  (unless url-setup-done

    ;; Make OS/2 happy
    ;;(push '("http" "80") tcp-binary-process-input-services)

    (mailcap-parse-mailcaps)
    (mailcap-parse-mimetypes)
    
    ;; Register all the authentication schemes we can handle
    (url-register-auth-scheme "basic" nil 4)
    (url-register-auth-scheme "digest" nil 7)

    (setq url-cookie-file
	  (or url-cookie-file
	      (expand-file-name "cookies" url-configuration-directory)))
    
    (setq url-history-file
	  (or url-history-file
	      (expand-file-name "history" url-configuration-directory)))
  
    ;; Parse the global history file if it exists, so that it can be used
    ;; for URL completion, etc.
    (url-history-parse-history)
    (url-history-setup-save-timer)

    ;; Ditto for cookies
    (url-cookie-setup-save-timer)
    (url-cookie-parse-file url-cookie-file)

    ;; Read in proxy gateways
    (let ((noproxy (and (not (assoc "no_proxy" url-proxy-services))
			(or (getenv "NO_PROXY")
			    (getenv "no_PROXY")
			    (getenv "no_proxy")))))
      (if noproxy
	  (setq url-proxy-services
		(cons (cons "no_proxy"
			    (concat "\\("
				    (mapconcat
				     (lambda (x)
				       (cond
					((= x ?,) "\\|")
					((= x ? ) "")
					((= x ?.) (regexp-quote "."))
					((= x ?*) ".*")
					((= x ??) ".")
					(t (char-to-string x))))
				     noproxy "") "\\)"))
		      url-proxy-services))))

    ;; Set the password entry funtion based on user defaults or guess
    ;; based on which remote-file-access package they are using.
    (cond
     (url-passwd-entry-func nil)	; Already been set
     ((fboundp 'read-passwd)		; Use secure password if available
      (setq url-passwd-entry-func 'read-passwd))
     ((or (featurep 'efs)		; Using EFS
	  (featurep 'efs-auto))		; or autoloading efs
      (if (not (fboundp 'read-passwd))
	  (autoload 'read-passwd "passwd" "Read in a password" nil))
      (setq url-passwd-entry-func 'read-passwd))
     ((or (featurep 'ange-ftp)		; Using ange-ftp
	  (and (boundp 'file-name-handler-alist)
	       (not (featurep 'xemacs)))) ; ??
      (setq url-passwd-entry-func 'ange-ftp-read-passwd))
     (t
      (url-warn
       'security
       "(url-setup): Can't determine how to read passwords, winging it.")))
  
    (url-setup-privacy-info)
    (run-hooks 'url-load-hook)
    (setq url-setup-done t)))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Retrieval functions
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defun url-retrieve (url callback &optional cbargs)
  "Retrieve URL asynchronously and call CALLBACK with CBARGS when finished.
The callback is called when the object has been completely retrieved, with
the current buffer containing the object, and any MIME headers associated
with it.  URL is either a string or a parsed URL.

Return the buffer URL will load into, or nil if the process has
already completed."
  (url-do-setup)
  (url-gc-dead-buffers)
  (if (stringp url)
       (set-text-properties 0 (length url) nil url))
  (if (not (vectorp url))
      (setq url (url-generic-parse-url url)))
  (if (not (functionp callback))
      (error "Must provide a callback function to url-retrieve"))
  (unless (url-type url)
    (error "Bad url: %s" (url-recreate-url url)))
  (let ((loader (url-scheme-get-property (url-type url) 'loader))
	(url-using-proxy (if (url-host url)
			     (url-find-proxy-for-url url (url-host url))))
	(buffer nil)
	(asynch (url-scheme-get-property (url-type url) 'asynchronous-p)))
    (if url-using-proxy
	(setq asynch t
	      loader 'url-proxy))
    (if asynch
	(setq buffer (funcall loader url callback cbargs))
      (setq buffer (funcall loader url))
      (if buffer
	  (save-excursion
	    (set-buffer buffer)
	    (apply callback cbargs))))
    (url-history-update-url url (current-time))
    buffer))

(defun url-retrieve-synchronously (url)
  "Retrieve URL synchronously.
Return the buffer containing the data, or nil if there are no data
associated with it (the case for dired, info, or mailto URLs that need
no further processing).  URL is either a string or a parsed URL."
  (url-do-setup)

  (lexical-let ((retrieval-done nil)
		(asynch-buffer nil))
    (setq asynch-buffer
	  (url-retrieve url (lambda (&rest ignored)
			      (url-debug 'retrieval "Synchronous fetching done (%S)" (current-buffer))
			      (setq retrieval-done t
				    asynch-buffer (current-buffer)))))
    (if (not asynch-buffer)
	;; We do not need to do anything, it was a mailto or something
	;; similar that takes processing completely outside of the URL
	;; package.
	nil
      (while (not retrieval-done)
	(url-debug 'retrieval "Spinning in url-retrieve-synchronously: %S (%S)"
		   retrieval-done asynch-buffer)
	;; Quoth monnier:
	;; It turns out that the problem seems to be that the (sit-for
	;; 0.1) below doesn't actually process the data: instead it
	;; returns immediately because there is keyboard input
	;; waiting, so we end up spinning endlessly waiting for the
	;; process to finish while not letting it finish.

	;; However, raman claims that it blocks Emacs with Emacspeak
	;; for unexplained reasons.  Put back for his benefit until
	;; someone can understand it.
	;; (sleep-for 0.1)
	(sit-for 0.1))
      asynch-buffer)))

(defun url-mm-callback (&rest ignored)
  (let ((handle (mm-dissect-buffer t)))
    (save-excursion
      (url-mark-buffer-as-dead (current-buffer))
      (set-buffer (generate-new-buffer (url-recreate-url url-current-object)))
      (if (eq (mm-display-part handle) 'external)
	  (progn
	    (set-process-sentinel
	     ;; Fixme: this shouldn't have to know the form of the
	     ;; undisplayer produced by `mm-display-part'.
	     (get-buffer-process (cdr (mm-handle-undisplayer handle)))
	     `(lambda (proc event)
		(mm-destroy-parts (quote ,handle))))
	    (message "Viewing externally")
	    (kill-buffer (current-buffer)))
	(display-buffer (current-buffer))
	(mm-destroy-parts handle)))))

(defun url-mm-url (url)
  "Retrieve URL and pass to the appropriate viewing application."
  (require 'mm-decode)
  (require 'mm-view)
  (url-retrieve url 'url-mm-callback nil))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Miscellaneous
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(defvar url-dead-buffer-list nil)

(defun url-mark-buffer-as-dead (buff)
  (push buff url-dead-buffer-list))

(defun url-gc-dead-buffers ()
  (let ((buff))
    (while (setq buff (pop url-dead-buffer-list))
      (if (buffer-live-p buff)
	  (kill-buffer buff)))))

(cond
 ((fboundp 'display-warning)
  (defalias 'url-warn 'display-warning))
 ((fboundp 'warn)
  (defun url-warn (class message &optional level)
    (warn "(%s/%s) %s" class (or level 'warning) message)))
 (t
  (defun url-warn (class message &optional level)
    (save-excursion
      (set-buffer (get-buffer-create "*URL-WARNINGS*"))
      (goto-char (point-max))
      (save-excursion
	(insert (format "(%s/%s) %s\n" class (or level 'warning) message)))
      (display-buffer (current-buffer))))))

(provide 'url)

;;; url.el ends here

Re: bug in url.el

[Michael Heerdegen]

ken <gebser@mousecar.com> writes:

> Some code developed a few years ago which worked fine up to my last
> upgrade of emacs now errors out with:

What's your Emacs version now?  The file you've send seems quite old...?

It seems that the problematic code has been changed, I don't see
url-passwd-entry-func, or any mention of passwords at all, in the
trunk's version of url.el.

> Finally, what could I easily and expediently do to work around this
> bug?

I'd try (setq url-passwd-entry-func nil), or an upgrade of Emacs if
possible.

HTH,

Michael.