image-dired: Minor cleanups

* lisp/image/image-dired-dired.el
(image-dired-dired-after-readin-hook, image-dired-minor-mode):
Minor doc fixes.
(image-dired-dired-display-image): Don't accept ineffectual prefix
argument.
* lisp/image/image-dired-util.el
(image-dired-file-name-at-point): Use when-let.
(image-dired-display-thumb-properties): Redefine as obsolete function
alias for 'image-dired-update-header-line'.

* lisp/image/image-dired-util.el
(image-dired-window-width-pixels): Make obsolete in favor of
window-body-width.
* lisp/image/image-dired.el (image-dired-line-up-dynamic)
(image-dired-display-window-width): Don't use above obsolete function.

lisp/image/image-dired-dired.el

@@ -81,7 +81,8 @@ previous -ARG, if ARG<0) files."
 (defun image-dired-dired-after-readin-hook ()
   "Relocate existing thumbnail overlays in Dired buffer after reverting.
 Move them to their corresponding files if they still exist.
-Otherwise, delete overlays."
+Otherwise, delete overlays.
+Used by `image-dired-dired-toggle-marked-thumbs'."
   (mapc (lambda (overlay)
           (when (overlay-get overlay 'put-image)
             (let* ((image-file (overlay-get overlay 'image-file))
@@ -289,12 +290,12 @@ With prefix argument ARG, create thumbnails even if they already exist
                    image-dired-external-viewer file)))
 
 ;;;###autoload
-(defun image-dired-dired-display-image (&optional arg)
+(defun image-dired-dired-display-image (&optional _)
   "Display current image file.
-See documentation for `image-dired-display-image' for more information.
-With prefix argument ARG, display image in its original size."
-  (interactive "P" dired-mode)
-  (image-dired-display-image (dired-get-filename) arg))
+See documentation for `image-dired-display-image' for more information."
+  (declare (advertised-calling-convention () "29.1"))
+  (interactive nil dired-mode)
+  (image-dired-display-image (dired-get-filename)))
 
 (defun image-dired-copy-with-exif-file-name ()
   "Copy file with unique name to main image directory.

lisp/image/image-dired-external.el

@@ -142,8 +142,7 @@ Available format specifiers are the same as in
   :version "26.1"
   :type '(repeat (string :tag "Argument")))
 
-(defcustom image-dired-cmd-rotate-original-program
-  "jpegtran"
+(defcustom image-dired-cmd-rotate-original-program "jpegtran"
   "Executable used to rotate original image.
 Used together with `image-dired-cmd-rotate-original-options'."
   :type 'file)
@@ -171,8 +170,7 @@ original image file name and %t which is replaced by
 Used together with `image-dired-cmd-write-exif-data-options'."
   :type 'file)
 
-(defcustom image-dired-cmd-write-exif-data-options
-  '("-%t=%v" "%f")
+(defcustom image-dired-cmd-write-exif-data-options '("-%t=%v" "%f")
   "Arguments of command used to write EXIF data.
 Used with `image-dired-cmd-write-exif-data-program'.
 Available format specifiers are: %f which is replaced by

lisp/image/image-dired-util.el

@@ -104,9 +104,8 @@ See also `image-dired-thumbnail-storage'."
 
 (defun image-dired-file-name-at-point ()
   "Get abbreviated file name for thumbnail or display image at point."
-  (let ((f (image-dired-original-file-name)))
-    (when f
-      (abbreviate-file-name f))))
+  (when-let ((f (image-dired-original-file-name)))
+    (abbreviate-file-name f)))
 
 (defun image-dired-associated-dired-buffer ()
   "Get associated Dired buffer at point."
@@ -119,10 +118,6 @@ See also `image-dired-thumbnail-storage'."
      (equal (window-buffer window) buf))
    nil t))
 
-(defun image-dired-window-width-pixels (window)
-  "Calculate WINDOW width in pixels."
-    (* (window-width window) (frame-char-width)))
-
 (defun image-dired-display-window ()
   "Return window where `image-dired-display-image-buffer' is visible."
   (get-window-with-predicate
@@ -152,6 +147,11 @@ See also `image-dired-thumbnail-storage'."
   "Return non-nil if there is an `image-dired' thumbnail at point."
   (get-text-property (point) 'image-dired-thumbnail))
 
+(defun image-dired-window-width-pixels (window)
+  "Calculate WINDOW width in pixels."
+  (declare (obsolete window-body-width "29.1"))
+  (* (window-width window) (frame-char-width)))
+
 (provide 'image-dired-util)
 
 ;; Local Variables:

lisp/image/image-dired.el

@@ -1056,13 +1056,13 @@ See also `image-dired-line-up-dynamic'."
 Calculate how many thumbnails fit."
   (interactive nil image-dired-thumbnail-mode)
   (let* ((char-width (frame-char-width))
-        (width (image-dired-window-width-pixels (image-dired-thumbnail-window)))
-        (image-dired-thumbs-per-row
-         (/ width
-            (+ (* 2 image-dired-thumb-relief)
-               (* 2 image-dired-thumb-margin)
-               (image-dired-thumb-size 'width)
-               char-width))))
+         (width (window-body-width (image-dired-thumbnail-window) t))
+         (image-dired-thumbs-per-row
+          (/ width
+             (+ (* 2 image-dired-thumb-relief)
+                (* 2 image-dired-thumb-margin)
+                (image-dired-thumb-size 'width)
+                char-width))))
     (image-dired-line-up)))
 
 (defun image-dired-line-up-interactive ()
@@ -1368,7 +1368,7 @@ completely fit)."
 (defun image-dired-display-window-width (window)
   "Return width, in pixels, of WINDOW."
   (declare (obsolete nil "29.1"))
-  (- (image-dired-window-width-pixels window)
+  (- (window-body-width window t)
      image-dired-display-window-width-correction))
 
 (defun image-dired-display-window-height (window)
@@ -1535,10 +1535,8 @@ Dired."
                   (cons (list tag file) (cdr image-dired-tag-file-list))))
       (setq image-dired-tag-file-list (list (list tag file))))))
 
-(defun image-dired-display-thumb-properties ()
-  "Display thumbnail properties in the echo area."
-  (declare (obsolete image-dired-update-header-line "29.1"))
-  (image-dired-update-header-line))
+(define-obsolete-function-alias 'image-dired-display-thumb-properties
+  #'image-dired-update-header-line "29.1")
 
 (defvar image-dired-slideshow-count 0
   "Keeping track on number of images in slideshow.")