bug#5102: 23.1; doc-view on a buffer not linked to a file

[Stefan Monnier <monnier@iro.umontreal.ca>]

>>> No, it cannot handle non-file buffers, because ghostscript and friends
>>> only handle input files and don't support piping in the output.  So the
>> It already has special code for Tramp and jka-compr files, where it
>> saves the buffer's content to a temp file.
>> Harven(?), does the patch below help?
> Mails to Harven bounce back with the error:
>   <harven@free.fr>: host mx1.free.fr said: 550 5.2.1 This mailbox
>     has been blocked due to inactivity (in reply to RCPT TO command)
> So I tried out your patch and it fails with:
>   Debugger entered--Lisp error: (wrong-type-argument stringp nil)
>     file-name-nondirectory(nil)
>     doc-view-mode()
>     doc-view-toggle-display()
>     call-interactively(doc-view-toggle-display nil nil)
> I don't understand how do you expect it to work.

Witha bit more help.  I've installed the patch below which seems to work
for me,


        Stefan


--- doc-view.el.~1.93.~	2009-11-30 22:13:35.000000000 -0500
+++ doc-view.el	2009-12-06 21:35:39.000000000 -0500
@@ -563,7 +563,7 @@
     (setq doc-view-current-cache-dir
 	  (file-name-as-directory
 	   (expand-file-name
-	    (concat (file-name-nondirectory buffer-file-name)
+	    (concat (file-name-nondirectory doc-view-buffer-file-name)
 		    "-"
 		    (let ((file doc-view-buffer-file-name))
 		      (with-temp-buffer
@@ -1228,6 +1228,7 @@
     (set (make-local-variable 'doc-view-buffer-file-name)
 	 (cond
 	  (jka-compr-really-do-compress
+           ;; FIXME: there's a risk of name conflicts here.
 	   (expand-file-name
 	    (file-name-nondirectory
 	     (file-name-sans-extension buffer-file-name))
@@ -1237,9 +1238,12 @@
 	  ;; supposed to return nil for things like local files accessed via
 	  ;; `su' or via file://...
 	  ((let ((file-name-handler-alist nil))
-	     (not (file-readable-p buffer-file-name)))
+	     (not (and buffer-file-name (file-readable-p buffer-file-name))))
+           ;; FIXME: there's a risk of name conflicts here.
 	   (expand-file-name
+	    (if buffer-file-name
 	    (file-name-nondirectory buffer-file-name)
+              (buffer-name))
 	    doc-view-cache-directory))
 	  (t buffer-file-name)))
     (when (not (string= doc-view-buffer-file-name buffer-file-name))