Fix up various corner case problems.

* doc-view.el (doc-view-last-page-number): New function.
(doc-view-mode, doc-view-last-page, doc-view-goto-page): Use it.
(doc-view-goto-page): Avoid inf-loops when the conversion fails.
(doc-view-kill-proc): Avoid inf-loop in freak cases.
(doc-view-reconvert-doc): Use the new recursive delete-directory.
(doc-view-convert-current-doc): Don't create the resolution.el file
here any more.
(doc-view-pdf/ps->png): Do it here instead.
(doc-view-already-converted-p): Check that resolution.el is present.
(doc-view-pdf->png): Don't rely on doc-view-pdf/ps->png for the few
windows that are not yet showing images.

2 files changed, 65 insertions, 34 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 0e831a4be72..0d1538c0136 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,18 @@
+2010-02-05  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        Fix up various corner case problems.
+        * doc-view.el (doc-view-last-page-number): New function.
+        (doc-view-mode, doc-view-last-page, doc-view-goto-page): Use it.
+        (doc-view-goto-page): Avoid inf-loops when the conversion fails.
+        (doc-view-kill-proc): Avoid inf-loop in freak cases.
+        (doc-view-reconvert-doc): Use the new recursive delete-directory.
+        (doc-view-convert-current-doc): Don't create the resolution.el file
+        here any more.
+        (doc-view-pdf/ps->png): Do it here instead.
+        (doc-view-already-converted-p): Check that resolution.el is present.
+        (doc-view-pdf->png): Don't rely on doc-view-pdf/ps->png for the few
+        windows that are not yet showing images.
+
 2010-02-04  Alan Mackenzie  <acm@muc.de>
 
         Change strategy for marking < and > as template delimiters: mark
diff --git a/lisp/doc-view.el b/lisp/doc-view.el
index d8a2e909732..5b84fc3e0d1 100644
--- a/lisp/doc-view.el
+++ b/lisp/doc-view.el
@@ -383,10 +383,13 @@ Can be `dvi', `pdf', or `ps'.")
 (defmacro doc-view-current-image () `(image-mode-window-get 'image))
 (defmacro doc-view-current-slice () `(image-mode-window-get 'slice))
 
+(defun doc-view-last-page-number ()
+  (length doc-view-current-files))
+
 (defun doc-view-goto-page (page)
   "View the page given by PAGE."
   (interactive "nPage: ")
-  (let ((len (length doc-view-current-files))
+  (let ((len (doc-view-last-page-number))
         (hscroll (window-hscroll)))
     (if (< page 1)
         (setq page 1)
@@ -426,12 +429,15 @@ Can be `dvi', `pdf', or `ps'.")
         ;; The PNG file hasn't been generated yet.
         (doc-view-pdf->png-1 doc-view-buffer-file-name file page
                              (lexical-let ((page page)
-                                           (win (selected-window)))
+                                           (win (selected-window))
+                                           (file file))
                                (lambda ()
                                  (and (eq (current-buffer) (window-buffer win))
                                       ;; If we changed page in the mean
                                       ;; time, don't mess things up.
                                       (eq (doc-view-current-page win) page)
+                                      ;; Make sure we don't infloop.
+                                      (file-readable-p file)
                                       (with-selected-window win
                                         (doc-view-goto-page page))))))))
     (overlay-put (doc-view-current-overlay)
@@ -455,7 +461,7 @@ Can be `dvi', `pdf', or `ps'.")
 (defun doc-view-last-page ()
   "View the last page."
   (interactive)
-  (doc-view-goto-page (length doc-view-current-files)))
+  (doc-view-goto-page (doc-view-last-page-number)))
 
 (defun doc-view-scroll-up-or-next-page (&optional arg)
   "Scroll page up ARG lines if possible, else goto next page.
@@ -528,7 +534,7 @@ at the top edge of the page moves to the previous page."
 (defun doc-view-kill-proc ()
   "Kill the current converter process(es)."
   (interactive)
-  (while doc-view-current-converter-processes
+  (while (consp doc-view-current-converter-processes)
     (ignore-errors ;; Maybe it's dead already?
       (kill-process (pop doc-view-current-converter-processes))))
   (when doc-view-current-timer
@@ -638,7 +644,7 @@ Should be invoked when the cached images aren't up-to-date."
   (doc-view-kill-proc)
   ;; Clear the old cached files
   (when (file-exists-p (doc-view-current-cache-dir))
-    (dired-delete-file (doc-view-current-cache-dir) 'always))
+    (delete-directory (doc-view-current-cache-dir) 'recursive))
   (doc-view-initiate-display))
 
 (defun doc-view-sentinel (proc event)
@@ -694,11 +700,18 @@ Should be invoked when the cached images aren't up-to-date."
            (list (format "-r%d" (round doc-view-resolution))
                  (concat "-sOutputFile=" png)
                  pdf-ps))
-   (lambda ()
-     (when doc-view-current-timer
-       (cancel-timer doc-view-current-timer)
-       (setq doc-view-current-timer nil))
-     (doc-view-display (current-buffer) 'force)))
+   (lexical-let ((resolution doc-view-resolution))
+     (lambda ()
+       ;; Only create the resolution file when it's all done, so it also
+       ;; serves as a witness that the conversion is complete.
+       (write-region (prin1-to-string resolution) nil
+                     (expand-file-name "resolution.el"
+                                       (doc-view-current-cache-dir))
+                     nil 'silently)
+       (when doc-view-current-timer
+         (cancel-timer doc-view-current-timer)
+         (setq doc-view-current-timer nil))
+       (doc-view-display (current-buffer) 'force))))
   ;; Update the displayed pages as soon as they're done generating.
   (when doc-view-conversion-refresh-interval
     (setq doc-view-current-timer
@@ -740,6 +753,13 @@ Start by converting PAGES, and then the rest."
              (doc-view-pdf->png pdf png rest)
            ;; Yippie, the important pages are done, update the display.
            (clear-image-cache)
+           ;; For the windows that have a message (like "Welcome to
+           ;; DocView") display property, clearing the image cache is
+           ;; not sufficient.
+           (dolist (win (get-buffer-window-list (current-buffer) nil 'visible))
+             (with-selected-window win
+               (when (stringp (get-char-property (point-min) 'display))
+                 (doc-view-goto-page (doc-view-current-page)))))
            ;; Convert the rest of the pages.
            (doc-view-pdf/ps->png pdf png)))))))
 
@@ -806,18 +826,8 @@ Those files are saved in the directory given by the function
   ;; resets during the redisplay).
   (setq doc-view-pending-cache-flush t)
   (let ((png-file (expand-file-name "page-%d.png"
-                                    (doc-view-current-cache-dir)))
-        (res-file (expand-file-name "resolution.el"
                                     (doc-view-current-cache-dir))))
     (make-directory (doc-view-current-cache-dir) t)
-    ;; Save the used resolution so that it can be restored when
-    ;; reading the cached files.
-    (let ((res doc-view-resolution))
-      (with-temp-buffer
-        (princ res (current-buffer))
-        ;; Don't use write-file, so as to avoid prompts for `require-newline',
-        ;; or for pre-existing buffers with the same name, ...
-        (write-region nil nil res-file nil 'silently)))
     (case doc-view-doc-type
       (dvi
        ;; DVI files have to be converted to PDF before Ghostscript can process
@@ -827,10 +837,10 @@ Those files are saved in the directory given by the function
             (png-file png-file))
          (doc-view-dvi->pdf doc-view-buffer-file-name pdf
                             (lambda () (doc-view-pdf/ps->png pdf png-file)))))
-     (pdf
-      (let ((pages (doc-view-active-pages)))
-        ;; Convert PDF to PNG images starting with the active pages.
-        (doc-view-pdf->png doc-view-buffer-file-name png-file pages)))
+      (pdf
+       (let ((pages (doc-view-active-pages)))
+         ;; Convert PDF to PNG images starting with the active pages.
+         (doc-view-pdf->png doc-view-buffer-file-name png-file pages)))
       (t
        ;; Convert to PNG images.
        (doc-view-pdf/ps->png doc-view-buffer-file-name png-file)))))
@@ -1129,7 +1139,13 @@ If BACKWARD is non-nil, jump to the previous match."
 (defun doc-view-already-converted-p ()
   "Return non-nil if the current doc was already converted."
   (and (file-exists-p (doc-view-current-cache-dir))
-       (> (length (directory-files (doc-view-current-cache-dir) nil "\\.png$")) 0)))
+       ;; Check that the resolution info is there, otherwise it means
+       ;; the conversion is incomplete.
+       (file-readable-p (expand-file-name "resolution.el"
+                                          (doc-view-current-cache-dir)))
+       (> (length (directory-files (doc-view-current-cache-dir)
+                                   nil "\\.png\\'"))
+          0)))
 
 (defun doc-view-initiate-display ()
   ;; Switch to image display if possible
@@ -1141,14 +1157,14 @@ If BACKWARD is non-nil, jump to the previous match."
             (progn
               (message "DocView: using cached files!")
               ;; Load the saved resolution
-              (let ((res-file (expand-file-name "resolution.el"
-                                                (doc-view-current-cache-dir)))
-                    (res doc-view-resolution))
-                (with-temp-buffer
-                  (when (file-exists-p res-file)
-                    (insert-file-contents res-file)
-                    (setq res (read (current-buffer)))))
-                (when (numberp res)
+              (let* ((res-file (expand-file-name "resolution.el"
+                                                 (doc-view-current-cache-dir)))
+                     (res
+                      (with-temp-buffer
+                        (when (file-readable-p res-file)
+                          (insert-file-contents res-file)
+                          (read (current-buffer))))))
+                (when (numberp res)
                   (set (make-local-variable 'doc-view-resolution) res)))
               (doc-view-display (current-buffer) 'force))
           (doc-view-convert-current-doc))
@@ -1282,7 +1298,7 @@ toggle between displaying the document or editing it as text.
 
     (set (make-local-variable 'mode-line-position)
          '(" P" (:eval (number-to-string (doc-view-current-page)))
-           "/" (:eval (number-to-string (length doc-view-current-files)))))
+           "/" (:eval (number-to-string (doc-view-last-page-number)))))
     ;; Don't scroll unless the user specifically asked for it.
     (set (make-local-variable 'auto-hscroll-mode) nil)
     (set (make-local-variable 'mwheel-scroll-up-function)