Default to rescaling images in mm buffers

* doc/misc/emacs-mime.texi (Display Customization): Document it.

* lisp/gnus/mm-decode.el (mm-inline-large-images): Change default
to `resize'.

3 files changed, 14 insertions, 11 deletions

diff --git a/doc/misc/emacs-mime.texi b/doc/misc/emacs-mime.texi
index 131a358ba59..8a1ba969ed9 100644
--- a/doc/misc/emacs-mime.texi
+++ b/doc/misc/emacs-mime.texi
@@ -375,16 +375,13 @@ message as follows:
 
 @item mm-inline-large-images
 @vindex mm-inline-large-images
-When displaying inline images that are larger than the window, Emacs
-does not enable scrolling, which means that you cannot see the whole
-image. To prevent this, the library tries to determine the image size
-before displaying it inline, and if it doesn't fit the window, the
-library will display it externally (e.g., with @samp{ImageMagick} or
-@samp{xv}). Setting this variable to @code{t} disables this check and
-makes the library display all inline images as inline, regardless of
-their size. If you set this variable to @code{resize}, the image will
-be displayed resized to fit in the window, if Emacs has the ability to
-resize images.
+This variable is @code{resize} by default, which means that images
+that are bigger than the Emacs window are resized so that they fit.
+If you set this to @code{nil}, large images are not displayed in
+Emacs, but can instead be displayed externally (e.g., with
+@samp{ImageMagick} or @samp{xv}). Setting this variable to @code{t}
+disables this check and makes the library display all inline images as
+inline, regardless of their size.
 
 @item mm-inline-large-images-proportion
 @vindex mm-inline-images-max-proportion
diff --git a/etc/NEWS b/etc/NEWS
index e7d054fd60e..12182694d1d 100644
--- a/etc/NEWS
+++ b/etc/NEWS
@@ -1063,6 +1063,11 @@ See the concept index in the Gnus manual for the 'match-list' entry.
 *** nil is no longer an allowed value for 'mm-text-html-renderer'.
 
 +++
+The default value of 'mm-inline-large-images' has changed from nil to
+'resize', which means that large images will be resized instead of
+displayed with an external program by default.
+
++++
 *** A new Gnus summary mode command, 'S A'
 ('gnus-summary-attach-article') can be used to attach the current
 article(s) to a pre-existing Message buffer, or create a new Message
diff --git a/lisp/gnus/mm-decode.el b/lisp/gnus/mm-decode.el
index a763e34785d..5636b8eca47 100644
--- a/lisp/gnus/mm-decode.el
+++ b/lisp/gnus/mm-decode.el
@@ -381,10 +381,11 @@ enables you to choose manually one of two types those mails include."
   :type 'directory
   :group 'mime-display)
 
-(defcustom mm-inline-large-images nil
+(defcustom mm-inline-large-images 'resize
   "If nil, images larger than the window aren't displayed in the buffer.
 If `resize', try to resize the images so they fit in the buffer.
 If t, show the images as they are without resizing."
+  :version "27.1"
   :type '(radio
           (const :tag "Inline large images as they are." t)
           (const :tag "Resize large images." resize)