Merge from origin/emacs-27

45a64c97c7 (origin/emacs-27) Clarify semantics of trace-function CONT...
821760fdc4 Don't let a code literal get modified in mml parsing (Bug#...
74a92be16d * lisp/simple.el (kill-ring-save): Doc fix.  (Bug#40797)
3d0e859692 Minor doc clarification regarding fringe bitmaps
4d86c7f822 Fix documentation of fringe bitmaps
a76af88dd8 Tweak mutability doc a bit more
f7e488d206 Calc: fix autoload errors (bug#40800)
369761b36d ; * src/xdisp.c: Improve the introductory commentary.
a92ca1f177 Improve indexing of ELisp manual
5a25d17760 * lisp/image-mode.el (image-transform-resize): Remove FIXM...
37ebec3a95 Improve the default value of 'doc-view-ghostscript-program'.
ba6104d1e8 Change doc-view-mode-map prefix key 's' to 'c'.
400ff5cd19 Improve wording about constants
d2836fe71b Improve the default value of 'doc-view-ghostscript-program'.
fc55f65305 Minor improvements in documentation of the last change
a64da75961 Add image-auto-resize defcustoms to image-mode.el
692ad40539 Improve the documentation of tab-bar and tab-line

# Conflicts:
#	etc/NEWS

7 files changed, 78 insertions, 31 deletions

diff --git a/lisp/calc/calc-ext.el b/lisp/calc/calc-ext.el
index bc70ec283fa..5c11554d5d7 100644
--- a/lisp/calc/calc-ext.el
+++ b/lisp/calc/calc-ext.el
@@ -674,7 +674,6 @@
   (define-key calc-mode-map "Z/" 'calc-kbd-break)
   (define-key calc-mode-map "Z`" 'calc-kbd-push)
   (define-key calc-mode-map "Z'" 'calc-kbd-pop)
-  (define-key calc-mode-map "Z=" 'calc-kbd-report)
   (define-key calc-mode-map "Z#" 'calc-kbd-query)
 
   (calc-init-prefixes)
@@ -845,8 +844,8 @@ math-bernoulli-number math-gammap1-raw)
  ("calc-incom" calc-digit-dots)
 
  ("calc-keypd" calc-do-keypad
-calc-keypad-x-left-click calc-keypad-x-middle-click
-calc-keypad-x-right-click)
+calc-keypad-left-click calc-keypad-middle-click
+calc-keypad-right-click)
 
  ("calc-lang" calc-set-language
 math-read-big-balance math-read-big-rec)
@@ -1003,7 +1002,7 @@ calc-find-root calc-poly-interp)
 calc-floor calc-idiv calc-increment calc-mant-part calc-max calc-min
 calc-round calc-scale-float calc-sign calc-trunc calc-xpon-part)
 
- ("calc-bin" calc-and calc-binary-radix calc-clip calc-twos-complement-mode
+ ("calc-bin" calc-and calc-binary-radix calc-clip
 calc-decimal-radix calc-diff calc-hex-radix calc-leading-zeros
 calc-lshift-arith calc-lshift-binary calc-not calc-octal-radix calc-or calc-radix
 calc-rotate-binary calc-rshift-arith calc-rshift-binary calc-word-size
@@ -1116,7 +1115,7 @@ calc-equal-to calc-get-user-defn calc-greater-equal calc-greater-than
 calc-in-set calc-kbd-break calc-kbd-else calc-kbd-else-if
 calc-kbd-end-for calc-kbd-end-if calc-kbd-end-loop calc-kbd-end-repeat
 calc-kbd-for calc-kbd-if calc-kbd-loop calc-kbd-pop calc-kbd-push
-calc-kbd-query calc-kbd-repeat calc-kbd-report calc-less-equal
+calc-kbd-query calc-kbd-repeat calc-less-equal
 calc-less-than calc-logical-and calc-logical-if calc-logical-not
 calc-logical-or calc-not-equal-to calc-pass-errors calc-remove-equal
 calc-timing calc-user-define calc-user-define-composition
diff --git a/lisp/calc/calc-prog.el b/lisp/calc/calc-prog.el
index e88aa92364c..6db5de4c96c 100644
--- a/lisp/calc/calc-prog.el
+++ b/lisp/calc/calc-prog.el
@@ -1452,11 +1452,6 @@ Redefine the corresponding command."
     (error "%s" "Unbalanced Z' in keyboard macro")))
 
 
-;; (defun calc-kbd-report (msg)
-;;   (interactive "sMessage: ")
-;;   (calc-wrapper
-;;    (math-working msg (calc-top-n 1))))
-
 (defun calc-kbd-query ()
   (interactive)
   (let ((defining-kbd-macro nil)
diff --git a/lisp/doc-view.el b/lisp/doc-view.el
index 8b3d5527f08..3cac2629a9c 100644
--- a/lisp/doc-view.el
+++ b/lisp/doc-view.el
@@ -59,16 +59,16 @@
 ;; will be remembered and applied to all pages of the current
 ;; document.  This enables you to cut away the margins of a document
 ;; to save some space.  To select a slice you can use
-;; `doc-view-set-slice' (bound to `s s') which will query you for the
+;; `doc-view-set-slice' (bound to `c s') which will query you for the
 ;; coordinates of the slice's top-left corner and its width and
 ;; height.  A much more convenient way to do the same is offered by
-;; the command `doc-view-set-slice-using-mouse' (bound to `s m').
+;; the command `doc-view-set-slice-using-mouse' (bound to `c m').
 ;; After invocation you only have to press mouse-1 at the top-left
 ;; corner and drag it to the bottom-right corner of the desired slice.
 ;; Even more accurate and convenient is to use
-;; `doc-view-set-slice-from-bounding-box' (bound to `s b') which uses
+;; `doc-view-set-slice-from-bounding-box' (bound to `c b') which uses
 ;; the BoundingBox information of the current page to set an optimal
-;; slice.  To reset the slice use `doc-view-reset-slice' (bound to `s
+;; slice.  To reset the slice use `doc-view-reset-slice' (bound to `c
 ;; r').
 ;;
 ;; You can also search within the document.  The command `doc-view-search'
@@ -155,9 +155,19 @@
 (defcustom doc-view-ghostscript-program
   (cond
    ((memq system-type '(windows-nt ms-dos))
-    "gswin32c")
-   (t
-    "gs"))
+    (cond
+     ;; Windows Ghostscript
+     ((executable-find "gswin64c") "gswin64c")
+     ((executable-find "gswin32c") "gswin32c")
+     ;; The GS wrapper coming with TeX Live
+     ((executable-find "rungs") "rungs")
+     ;; The MikTeX builtin GS Check if mgs is functional for external
+     ;; non-MikTeX apps.  Was available under:
+     ;; http://blog.miktex.org/post/2005/04/07/Starting-mgsexe-at-the-DOS-Prompt.aspx
+     ((and (executable-find "mgs")
+           (= 0 (shell-command "mgs -q -dNODISPLAY -c quit")))
+      "mgs")))
+   (t "gs"))
   "Program to convert PS and PDF files to PNG."
   :type 'file
   :version "27.1")
@@ -421,10 +431,10 @@ Typically \"page-%s.png\".")
     ;; Killing the buffer (and the process)
     (define-key map (kbd "K")         'doc-view-kill-proc)
     ;; Slicing the image
-    (define-key map (kbd "s s")       'doc-view-set-slice)
-    (define-key map (kbd "s m")       'doc-view-set-slice-using-mouse)
-    (define-key map (kbd "s b")       'doc-view-set-slice-from-bounding-box)
-    (define-key map (kbd "s r")       'doc-view-reset-slice)
+    (define-key map (kbd "c s")       'doc-view-set-slice)
+    (define-key map (kbd "c m")       'doc-view-set-slice-using-mouse)
+    (define-key map (kbd "c b")       'doc-view-set-slice-from-bounding-box)
+    (define-key map (kbd "c r")       'doc-view-reset-slice)
     ;; Searching
     (define-key map (kbd "C-s")       'doc-view-search)
     (define-key map (kbd "<find>")    'doc-view-search)
diff --git a/lisp/emacs-lisp/trace.el b/lisp/emacs-lisp/trace.el
index 5c35036a50d..4ebb7ff711d 100644
--- a/lisp/emacs-lisp/trace.el
+++ b/lisp/emacs-lisp/trace.el
@@ -292,7 +292,9 @@ If `current-prefix-arg' is non-nil, also read a buffer and a \"context\"
 (defun trace-function-foreground (function &optional buffer context)
   "Trace calls to function FUNCTION.
 With a prefix argument, also prompt for the trace buffer (default
-`trace-buffer'), and a Lisp expression CONTEXT.
+`trace-buffer'), and a Lisp expression CONTEXT.  When called from
+Lisp, CONTEXT should be a function of no arguments which returns
+a value to insert into BUFFER during the trace.
 
 Tracing a function causes every call to that function to insert
 into BUFFER Lisp-style trace messages that display the function's
diff --git a/lisp/gnus/mml.el b/lisp/gnus/mml.el
index 2006837d6a7..21491499eb8 100644
--- a/lisp/gnus/mml.el
+++ b/lisp/gnus/mml.el
@@ -281,7 +281,7 @@ part.  This is for the internal use, you should never modify the value.")
             (setq tag (mml-read-tag)
                   no-markup-p nil
                   warn nil)
-          (setq tag (list 'part '(type . "text/plain"))
+          (setq tag (list 'part (cons 'type "text/plain"))
                 no-markup-p t
                 warn t))
         (setq raw (cdr (assq 'raw tag))
diff --git a/lisp/image-mode.el b/lisp/image-mode.el
index fbce1193cd0..3ee185a0dc5 100644
--- a/lisp/image-mode.el
+++ b/lisp/image-mode.el
@@ -53,11 +53,37 @@ See `image-mode-winprops'.")
   "Special hook run when image data is requested in a new window.
 It is called with one argument, the initial WINPROPS.")
 
-;; FIXME this doesn't seem mature yet. Document in manual when it is.
+(defcustom image-auto-resize t
+  "Non-nil to resize the image upon first display.
+Its value should be one of the following:
+ - nil, meaning no resizing.
+ - t, meaning to fit the image to the window height and width.
+ - `fit-height', meaning to fit the image to the window height.
+ - `fit-width', meaning to fit the image to the window width.
+ - A number, which is a scale factor (the default size is 1)."
+  :type '(choice (const :tag "No resizing" nil)
+                 (other :tag "Fit height and width" t)
+                 (const :tag "Fit height" fit-height)
+                 (const :tag "Fit width" fit-width)
+                 (number :tag "Scale factor" 1))
+  :version "27.1"
+  :group 'image)
+
+(defcustom image-auto-resize-on-window-resize 1
+  "Non-nil to resize the image whenever the window's dimensions change.
+This will always keep the image fit to the window.
+When non-nil, the value should be a number of seconds to wait before
+resizing according to the value specified in `image-auto-resize'."
+  :type '(choice (const :tag "No auto-resize on window size change" nil)
+                 (integer :tag "Wait for number of seconds before resize" 1))
+  :version "27.1"
+  :group 'image)
+
 (defvar-local image-transform-resize nil
   "The image resize operation.
 Its value should be one of the following:
  - nil, meaning no resizing.
+ - t, meaning to fit the image to the window height and width.
  - `fit-height', meaning to fit the image to the window height.
  - `fit-width', meaning to fit the image to the window width.
  - A number, which is a scale factor (the default size is 1).")
@@ -427,9 +453,10 @@ call."
     (define-key map "sf" 'image-mode-fit-frame)
     (define-key map "sh" 'image-transform-fit-to-height)
     (define-key map "sw" 'image-transform-fit-to-width)
+    (define-key map "sb" 'image-transform-fit-both)
+    (define-key map "ss" 'image-transform-set-scale)
     (define-key map "sr" 'image-transform-set-rotation)
     (define-key map "s0" 'image-transform-reset)
-    (define-key map "ss" 'image-transform-set-scale)
 
     ;; Multi-frame keys
     (define-key map (kbd "RET") 'image-toggle-animation)
@@ -482,6 +509,10 @@ call."
          :help "Resize image to match the window height"]
         ["Fit to Window Width" image-transform-fit-to-width
          :help "Resize image to match the window width"]
+        ["Fit to Window Height and Width" image-transform-fit-both
+         :help "Resize image to match the window height and width"]
+        ["Set Scale..." image-transform-set-scale
+         :help "Resize image by specified scale factor"]
         ["Rotate Image..." image-transform-set-rotation
          :help "Rotate the image"]
         ["Reset Transformations" image-transform-reset
@@ -569,6 +600,7 @@ Key bindings:
 
   (major-mode-suspend)
   (setq major-mode 'image-mode)
+  (setq image-transform-resize image-auto-resize)
 
   (if (not (image-get-display-property))
       (progn
@@ -611,7 +643,8 @@ Key bindings:
 
   (add-hook 'change-major-mode-hook #'image-toggle-display-text nil t)
   (add-hook 'after-revert-hook #'image-after-revert-hook nil t)
-  (add-hook 'window-state-change-functions #'image--window-state-change nil t)
+  (when image-auto-resize-on-window-resize
+    (add-hook 'window-state-change-functions #'image--window-state-change nil t))
 
   (run-mode-hooks 'image-mode-hook)
   (let ((image (image-get-display-property))
@@ -768,7 +801,7 @@ was inserted."
             filename))
          ;; If we have a `fit-width' or a `fit-height', don't limit
          ;; the size of the image to the window size.
-         (edges (and (null image-transform-resize)
+         (edges (and (eq image-transform-resize t)
                      (window-inside-pixel-edges (get-buffer-window))))
          (type (if (image--imagemagick-wanted-p filename)
                    'imagemagick
@@ -878,7 +911,9 @@ Otherwise, display the image by calling `image-mode'."
   ;; image resizing happens later during redisplay.  So if those
   ;; consecutive calls happen without any redisplay between them,
   ;; the costly operation of image resizing should happen only once.
-  (run-with-idle-timer 1 nil #'image-fit-to-window window))
+  (when (numberp image-auto-resize-on-window-resize)
+    (run-with-idle-timer image-auto-resize-on-window-resize nil
+                         #'image-fit-to-window window)))
 
 (defun image-fit-to-window (window)
   "Adjust size of image to display it exactly in WINDOW boundaries."
@@ -1282,7 +1317,7 @@ These properties are determined by the Image mode variables
 `image-transform-resize' and `image-transform-rotation'.  The
 return value is suitable for appending to an image spec."
   (setq image-transform-scale 1.0)
-  (when (or image-transform-resize
+  (when (or (not (memq image-transform-resize '(nil t)))
             (/= image-transform-rotation 0.0))
     ;; Note: `image-size' looks up and thus caches the untransformed
     ;; image.  There's no easy way to prevent that.
@@ -1328,6 +1363,12 @@ return value is suitable for appending to an image spec."
   (setq image-transform-resize 'fit-width)
   (image-toggle-display-image))
 
+(defun image-transform-fit-both ()
+  "Fit the current image both to the height and width of the current window."
+  (interactive)
+  (setq image-transform-resize t)
+  (image-toggle-display-image))
+
 (defun image-transform-set-rotation (rotation)
   "Prompt for an angle ROTATION, and rotate the image by that amount.
 ROTATION should be in degrees."
@@ -1338,7 +1379,7 @@ ROTATION should be in degrees."
 (defun image-transform-reset ()
   "Display the current image with the default size and rotation."
   (interactive)
-  (setq image-transform-resize nil
+  (setq image-transform-resize image-auto-resize
         image-transform-rotation 0.0
         image-transform-scale 1)
   (image-toggle-display-image))
diff --git a/lisp/simple.el b/lisp/simple.el
index 8bc84a9dfa0..b5ba05426f5 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -4846,7 +4846,7 @@ In Transient Mark mode, deactivate the mark.
 If `interprogram-cut-function' is non-nil, also save the text for a window
 system cut and paste.
 
-If you want to append the killed line to the last killed text,
+If you want to append the killed region to the last killed text,
 use \\[append-next-kill] before \\[kill-ring-save].
 
 The copied text is filtered by `filter-buffer-substring' before it is