Re: cl-assertion error in doc-view

[Tassilo Horn <tsdh@gnu.org>]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> So we need a different solution that does not rely on displaying
>>> the buffer.
>> What's the purpose of a thing called `doc-view-display' if it's not
>> to display something?
>
> It's to setup the overlays and properties so that the text is replaced
> by the page images (using the `display' property).  That's orthogonal
> to whether the buffer is displayed in a window.

How about using `set-window-buffer' and `save-window-excursion' like so?
That also does the right thing, that is, not show the buffer forcefully,
with `find-file-noselect'.

--8<---------------cut here---------------start------------->8---
=== modified file 'lisp/doc-view.el'
--- lisp/doc-view.el    2012-09-20 19:53:40 +0000
+++ lisp/doc-view.el    2012-09-21 07:05:40 +0000
@@ -1169,25 +1169,25 @@
 If FORCE is non-nil, start viewing even if the document does not
 have the page we want to view."
   (with-current-buffer buffer
-    (let ((prev-pages doc-view-current-files)
-         (windows (get-buffer-window-list buffer nil t)))
+    (let ((prev-pages doc-view-current-files))
       (setq doc-view-current-files
             (sort (directory-files (doc-view-current-cache-dir) t
                                    "page-[0-9]+\\.png" t)
                   'doc-view-sort))
-      (unless windows
-       (switch-to-buffer buffer)
-       (setq windows (get-buffer-window-list buffer nil t)))
-      (dolist (win windows)
-       (let* ((page (doc-view-current-page win))
-              (pagefile (expand-file-name (format "page-%d.png" page)
-                                          (doc-view-current-cache-dir))))
-         (when (or force
-                   (and (not (member pagefile prev-pages))
-                        (member pagefile doc-view-current-files)))
-           (with-selected-window win
-             (cl-assert (eq (current-buffer) buffer) t)
-             (doc-view-goto-page page))))))))
+      (save-window-excursion
+       (dolist (win (or (get-buffer-window-list buffer nil t)
+                        (let ((w (selected-window)))
+                          (set-window-buffer w buffer)
+                          (list w))))
+         (let* ((page (doc-view-current-page win))
+                (pagefile (expand-file-name (format "page-%d.png" page)
+                                            (doc-view-current-cache-dir))))
+           (when (or force
+                     (and (not (member pagefile prev-pages))
+                          (member pagefile doc-view-current-files)))
+             (with-selected-window win
+               (cl-assert (eq (current-buffer) buffer) t)
+               (doc-view-goto-page page)))))))))
 
 (defun doc-view-buffer-message ()
   ;; Only show this message initially, not when refreshing the buffer (in which
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo