Backport latest doc-view fix

* doc/emacs/misc.texi (Document View): Adapt to latest doc-view changes wrt
viewing the document's plain text contents.  [Backport]

* lisp/doc-view.el (doc-view-open-text): View the document's plain text
in the current buffer instead of a new one.
(doc-view-toggle-display): Handle the case where the current
buffer contains the plain text contents of the document.
(doc-view-initiate-display): Don't switch to fallback mode if the
user wants to view the doc's plain text.  [Backport]

2 files changed, 55 insertions, 26 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index d32c2772579..67efd558528 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,12 @@
+2014-10-23  Tassilo Horn  <tsdh@gnu.org>
+
+        * doc-view.el (doc-view-open-text): View the document's plain text
+        in the current buffer instead of a new one.
+        (doc-view-toggle-display): Handle the case where the current
+        buffer contains the plain text contents of the document.
+        (doc-view-initiate-display): Don't switch to fallback mode if the
+        user wants to view the doc's plain text.  [Backport]
+
 2014-10-23  Eli Zaretskii  <eliz@gnu.org>
 
         * startup.el (fancy-about-text): Read the entire tutorial, not
diff --git a/lisp/doc-view.el b/lisp/doc-view.el
index 7d5f1e771d5..4b90a42c498 100644
--- a/lisp/doc-view.el
+++ b/lisp/doc-view.el
@@ -1398,19 +1398,28 @@ For now these keys are useful:
   (tooltip-show (doc-view-current-info)))
 
 (defun doc-view-open-text ()
-  "Open a buffer with the current doc's contents as text."
+  "Display the current doc's contents as text."
   (interactive)
   (if doc-view--current-converter-processes
       (message "DocView: please wait till conversion finished.")
-    (let ((txt (expand-file-name "doc.txt" (doc-view--current-cache-dir)))
-          (bname (or buffer-file-name (buffer-name))))
+    (let ((txt (expand-file-name "doc.txt" (doc-view--current-cache-dir))))
       (if (file-readable-p txt)
-          (let ((name (concat "Text contents of "
-                              (file-name-nondirectory bname)))
-                (dir (or (file-name-directory bname) default-directory)))
-            (with-current-buffer (find-file txt)
-              (rename-buffer name)
-              (setq default-directory dir)))
+          (let ((inhibit-read-only t)
+                (buffer-undo-list t)
+                (dv-bfn doc-view--buffer-file-name))
+            (erase-buffer)
+            (set-buffer-multibyte t)
+            (insert-file-contents txt)
+            (text-mode)
+            (setq-local doc-view--buffer-file-name dv-bfn)
+            (set-buffer-modified-p nil)
+            (doc-view-minor-mode)
+            (add-hook 'write-file-functions
+                      (lambda ()
+                        (when (eq major-mode 'text-mode)
+                          (error "Cannot save text contents of document %s"
+                                 buffer-file-name)))
+                      nil t))
         (doc-view-doc->txt txt 'doc-view-open-text)))))
 
 ;;;;; Toggle between editing and viewing
@@ -1422,20 +1431,30 @@ For now these keys are useful:
 (defun doc-view-toggle-display ()
   "Toggle between editing a document as text or viewing it."
   (interactive)
-  (if (eq major-mode 'doc-view-mode)
-      ;; Switch to editing mode
-      (progn
-        (doc-view-kill-proc)
-        (setq buffer-read-only nil)
-        ;; Switch to the previously used major mode or fall back to
-        ;; normal mode.
-        (doc-view-fallback-mode)
-        (doc-view-minor-mode 1))
+  (cond
+   ((eq major-mode 'doc-view-mode)
+    ;; Switch to editing mode
+    (doc-view-kill-proc)
+    (setq buffer-read-only nil)
+    ;; Switch to the previously used major mode or fall back to
+    ;; normal mode.
+    (doc-view-fallback-mode)
+    (doc-view-minor-mode 1))
+   ((eq major-mode 'text-mode)
+    (let ((buffer-undo-list t))
+      ;; We're currently viewing the document's text contents, so switch
+      ;; back to .
+      (setq buffer-read-only nil)
+      (insert-file-contents doc-view--buffer-file-name nil nil nil t)
+      (doc-view-fallback-mode)
+      (doc-view-minor-mode 1)
+      (set-buffer-modified-p nil)))
+   (t
     ;; Switch to doc-view-mode
     (when (and (buffer-modified-p)
                (y-or-n-p "The buffer has been modified.  Save the changes? "))
       (save-buffer))
-    (doc-view-mode)))
+    (doc-view-mode))))
 
 ;;;; Searching
 
@@ -1591,11 +1610,11 @@ If BACKWARD is non-nil, jump to the previous match."
      (concat "No PNG support is available, or some conversion utility for "
              (file-name-extension doc-view--buffer-file-name)
              " files is missing."))
-    (when (and (executable-find doc-view-pdftotext-program)
-               (y-or-n-p
-                "Unable to render file.  View extracted text instead? "))
-      (doc-view-open-text))
-    (doc-view-toggle-display)))
+    (if (and (executable-find doc-view-pdftotext-program)
+             (y-or-n-p
+              "Unable to render file.  View extracted text instead? "))
+        (doc-view-open-text)
+      (doc-view-toggle-display))))
 
 (defvar bookmark-make-record-function)
 
@@ -1622,7 +1641,7 @@ If BACKWARD is non-nil, jump to the previous match."
   "Figure out the current document type (`doc-view-doc-type')."
   (let ((name-types
          (when buffer-file-name
-           (cdr (assoc (file-name-extension buffer-file-name)
+           (cdr (assoc-ignore-case (file-name-extension buffer-file-name)
                        '(
                          ;; DVI
                          ("dvi" dvi)
@@ -1639,7 +1658,8 @@ If BACKWARD is non-nil, jump to the previous match."
                          ;; Microsoft Office formats (also handled
                          ;; by the odf conversion chain)
                          ("doc" odf) ("docx" odf) ("xls" odf) ("xlsx" odf)
-                         ("ppt" odf) ("pptx" odf))))))
+                         ("ppt" odf) ("pptx" odf)
+                         ("ppt" odf) ("pps" odf) ("pptx" odf))))))
         (content-types
          (save-excursion
            (goto-char (point-min))