Re: notmuch-emacs inline image display broken in emacs-29

[David Bremner <david@tethera.net>]

[-- Attachment #1: Type: text/plain, Size: 1733 bytes --]

Alex Murray <alex.murray@canonical.com> writes:

> Hi folks,
>
> I have noticed that inline image display doesn't work anymore in
> emacs-29 / git master and have tracked it down to a change to the way
> mm-inline-image inserts an image into the buffer.
>
> In
> https://git.savannah.gnu.org/cgit/emacs.git/commit/?id=d2186160a9e978960c0f96bc3b4fc65b5affc170
> mm-inline-image was changed to use insert-image instead of
> put-image. This inserts the image into the buffer using a single space
> as the string contents with a display property set as the image contents
> so that the single space is not shown itself but instead the image is
> shown in its place.
>
> I had thought the culprit then was the use of
> notmuch-wash-elide-blank-lines within the default value of
> notmuch-show-insert-text/plain-hook - assuming that since the line
> containing the image is now just a single space, it then gets deleted
> from the buffer and the image is never shown. However, even after
> setting notmuch-show-insert-text/plain-hook to nil, images are still not
> shown inline by notmuch.
>
> However, if I locally redefine mm-inline-image to use say a period "."
> as the string argument to insert-image then the image appears as
> expected.
>
> Any thoughts on what may be happening here and how best to resolve this?
>

The problem seems to be the call to indent-rigidly in
notmuch-show-lazy-part. The image is actually inserted OK, but then
apparently deleted by indent-rigidly (probably because it looks like
whitespace).

I tried replacing indent-rigidly with a simplified version the and that
leaves the image inserted, but unfortunately doesn't indent it
properly. If you want to play with it, my half working patch is
attached.


[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: 0001-WIP-replace-use-of-indent-rigidly-in-notmuch-show-la.patch --]
[-- Type: text/x-diff, Size: 1695 bytes --]

From 484f78e11d7f520b76b30b7d92aec15ff71f215f Mon Sep 17 00:00:00 2001
From: David Bremner <david@tethera.net>
Date: Sat, 25 Feb 2023 09:12:57 -0400
Subject: [PATCH] WIP: replace use of indent-rigidly in notmuch-show-lazy

---
 emacs/notmuch-show.el | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/emacs/notmuch-show.el b/emacs/notmuch-show.el
index 36cce619..522ba1fd 100644
--- a/emacs/notmuch-show.el
+++ b/emacs/notmuch-show.el
@@ -324,6 +324,25 @@ position of the message in the thread."
 
 ;;; Utilities
 
+;; force all indentation to be spaces at BOL
+;; Based on apply-on-rectangle, from rect.el
+(defun notmuch--indent-rigidly (start end count)
+  (cond
+   ((zerop count) t)
+   ((< count 0) (indent-rigidly start end count))
+   (t
+    (save-excursion
+      (let ((startpt (progn (goto-char start) (line-beginning-position)))
+	    (endpt (progn (goto-char end) (line-end-position)))
+	    (spaces (spaces-string count)))
+	(goto-char startpt)
+	(while
+	    (progn
+	      (insert spaces)
+	      (cl-incf endpt count)
+	      (and (zerop (forward-line 1)) (bolp)
+		   (<= (point) endpt)))))))))
+
 (defmacro with-current-notmuch-show-message (&rest body)
   "Evaluate body with current buffer set to the text of current message."
   `(save-excursion
@@ -1024,7 +1043,7 @@ will return nil if the CID is unknown or cannot be retrieved."
 	(narrow-to-region part-beg part-end)
 	(delete-region part-beg part-end)
 	(apply #'notmuch-show-insert-bodypart-internal part-args)
-	(indent-rigidly part-beg
+	(notmuch--indent-rigidly part-beg
 			part-end
 			(* notmuch-show-indent-messages-width depth)))
       (goto-char part-end)
-- 
2.39.1


[-- Attachment #3: Type: text/plain, Size: 0 bytes --]