bug#29047: 26.0.90; shr hang (regression from 25.3)

[Katsumi Yamaoka]

On Sun, 29 Oct 2017 16:07:34 +0200, Eli Zaretskii wrote:
> Thanks, this bug was introduced by 9eb028f, and the problematic
> property is 'display' with value '(space :align-to (NNN))'.  It
> causes shr-fill-line to infloop when this property is put on a
> newline.

Sorry, I did the 9eb028f change for fixing bug#24034:
<https://lists.gnu.org/archive/html/bug-gnu-emacs/2016-07/msg01042.html>

> I can prevent the loop with the patch below.  I'm not sure this is the
> right fix, though.  Comments?

That's ok, but the properties necessary to copy there are only
`face' and `image-displayer'.  How about this one?

* lisp/net/shr.el (shr-fill-line): Copy only face and image-displayer
properties to gaps (bug#29047).

--- shr.el~     2017-10-29 22:05:08.139411500 +0000
+++ shr.el      2017-10-30 06:19:48.874402200 +0000
@@ -700,12 +700,16 @@
       ;; Success; continue.
       (when (= (preceding-char) ?\s)
        (delete-char -1))
-      (let ((props (text-properties-at (point)))
+      (let ((props `(face ,(get-text-property (point) 'face)
+                         ;; Don't break the image-displayer property
+                         ;; as it will cause `gnus-article-show-images'
+                         ;; to show the two or more same images.
+                         image-displayer
+                         ,(get-text-property (point) 'image-displayer)))
            (gap-start (point)))
        (insert "\n")
        (shr-indent)
-       (when props
-         (add-text-properties gap-start (point) props)))
+       (add-text-properties gap-start (point) props))
       (setq start (point))
       (shr-vertical-motion shr-internal-width)
       (when (looking-at " $")