Make doc-view work with text-mode as default major-mode (bug#34451)

* lisp/doc-view.el (doc-view--text-view-mode): New alias for view-mode.
(doc-view-open-text): Use it.
(doc-view-toggle-display): Use it.

1 files changed, 12 insertions, 3 deletions

diff --git a/lisp/doc-view.el b/lisp/doc-view.el
index 7ae7c6a96cd..53ae351abd8 100644
--- a/lisp/doc-view.el
+++ b/lisp/doc-view.el
@@ -1476,6 +1476,15 @@ For now these keys are useful:
   (interactive)
   (tooltip-show (doc-view-current-info)))
 
+;; We define an own major mode for DocView's text display so that we
+;; can easily distinguish when we want to toggle back because
+;; text-mode is a likely candidate for a default major-mode
+;; (bug#34451).
+(defun doc-view--text-view-mode ()
+  "View mode used in DocView's text buffers."
+  (view-mode)
+  (setq major-mode 'doc-view--text-view-mode))
+
 (defun doc-view-open-text ()
   "Display the current doc's contents as text."
   (interactive)
@@ -1489,13 +1498,13 @@ For now these keys are useful:
             (erase-buffer)
             (set-buffer-multibyte t)
             (insert-file-contents txt)
-            (text-mode)
+            (doc-view--text-view-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)
+                        (when (eq major-mode 'doc-view--text-view-mode)
                           (error "Cannot save text contents of document %s"
                                  buffer-file-name)))
                       nil t))
@@ -1519,7 +1528,7 @@ For now these keys are useful:
     ;; normal mode.
     (doc-view-fallback-mode)
     (doc-view-minor-mode 1))
-   ((eq major-mode 'text-mode)
+   ((eq major-mode 'doc-view--text-view-mode)
     (let ((buffer-undo-list t))
       ;; We're currently viewing the document's text contents, so switch
       ;; back to .