Make mm-html-blocked-images default to "" again

* lisp/gnus/mm-decode.el (mm-html-blocked-images):
Default to "" that blocks all external images.

* doc/misc/emacs-mime.texi (Display Customization):
Mention that mm-html-blocked-images defaults to "".

2 files changed, 2 insertions, 2 deletions

diff --git a/doc/misc/emacs-mime.texi b/doc/misc/emacs-mime.texi
index b7c58d7ebeb..9c4f10ec90c 100644
--- a/doc/misc/emacs-mime.texi
+++ b/doc/misc/emacs-mime.texi
@@ -436,7 +436,7 @@ It is effective when @code{mm-text-html-renderer} (@pxref{Display
 Customization}) is @code{shr}.  In Gnus, this is overridden by the value
 of @code{gnus-blocked-images} or the return value of the function that
 @code{gnus-blocked-images} is set to (@pxref{HTML, ,HTML, gnus, Gnus
-manual}).  The default is @code{nil}.
+manual}).  The default is @code{""} that blocks all external images.
 
 @item mm-w3m-safe-url-regexp
 @vindex mm-w3m-safe-url-regexp
diff --git a/lisp/gnus/mm-decode.el b/lisp/gnus/mm-decode.el
index c45258e987c..f70877dc63a 100644
--- a/lisp/gnus/mm-decode.el
+++ b/lisp/gnus/mm-decode.el
@@ -151,7 +151,7 @@ nil    : use external viewer (default web browser)."
   :type 'boolean
   :group 'mime-display)
 
-(defcustom mm-html-blocked-images nil
+(defcustom mm-html-blocked-images ""
   "Regexp matching image URLs to be blocked, or nil meaning not to block.
 Note that cid images that are embedded in a message won't be blocked."
   :version "25.1"