Re: rfn-eshadow

[Stefan Monnier]

>>> Thanks, but it now produces weird results, e.g. removing a letter from
>>> the beginning of an URL and retyping it again doesn't remove the file name
>>> shadow.  This is because url-handlers.el is not loaded, and url-file-handler
>>> is undefined.  I see two variants of fixing this: either by explicitly
>>> loading url-handlers.el, or adding an ###autoload cookie to url-file-handler
>>> (I think this is better).
>> 
>> I've done the latter.

> After your changes arrived to the trunk I observe a strange behavior:

> 1. emacs -Q
> 2. M-x ffap-bindings RET
> 3. C-x C-f C-a C-k / s u : : / C-g
> 4. C-h v file-name-handler-alist RET

> And `file-name-handler-alist' doesn't contain `tramp-file-name-handler'
> anymore.  But in the Emacs 22 branch everything is correct.
> Do you see the same?

Indeed, in the above recipe, Tramp gets loaded while we're inside the
ffap, i.e. while inside the `let' binding, so the
tramp-file-name-handler' gets removed when get out of the let
binding :-(
I.e. we shouldn't use let-binding.  I installed the untested patch below
which should hopefully fix this problem.


        Stefan


--- ffap.el.~1.68.~     2008-01-08 21:08:40.000000000 -0500
+++ ffap.el     2008-01-08 21:13:19.000000000 -0500
@@ -1263,10 +1263,10 @@
          (setq dir (file-name-directory guess))))
     (let ((minibuffer-completing-file-name t)
          (completion-ignore-case read-file-name-completion-ignore-case)
-         ;; because of `rfn-eshadow-update-overlay'.
-         (file-name-handler-alist
-          (cons (cons ffap-url-regexp 'url-file-handler)
-                file-name-handler-alist)))
+          (fnh-elem (cons ffap-url-regexp 'url-file-handler)))
+      ;; Explain to `rfn-eshadow' that we can use URLs here.
+      (push fnh-elem file-name-handler-alist)
+      (unwind-protect
       (setq guess
            (completing-read
             prompt
@@ -1276,7 +1276,12 @@
             (if dir (cons guess (length dir)) guess)
             (list 'file-name-history)
             (and buffer-file-name
-                 (abbreviate-file-name buffer-file-name)))))
+                      (abbreviate-file-name buffer-file-name))))
+        ;; Remove the special handler manually.  We used to just let-bind
+        ;; file-name-handler-alist to preserve its value, but that caused
+        ;; other modifications to be lost (e.g. when Tramp gets loaded
+        ;; during the completing-read call).
+        (setq file-name-handler-alist (delq fnh-elem 
file-name-handler-alist))))
     ;; Do file substitution like (interactive "F"), suggested by MCOOK.
     (or (ffap-url-p guess) (setq guess (substitute-in-file-name guess)))
     ;; Should not do it on url's, where $ is a common (VMS?) character.