Handle HTML 'ol' start attribute in shr.el

* lisp/net/shr.el (shr-tag-ol): Don't automatically assume
1-indexing for all ordered lists, use <ol> if given.

* etc/NEWS: Announce change in shr behavior.

* test/data/shr/ol.html:
* test/data/shr/ol.txt: New test data files.

1 files changed, 8 insertions, 1 deletions

diff --git a/lisp/net/shr.el b/lisp/net/shr.el
index 94d68faf2a8..2f628e1caa2 100644
--- a/lisp/net/shr.el
+++ b/lisp/net/shr.el
@@ -1755,7 +1755,14 @@ The preference is a float determined from `shr-prefer-media-type'."
 
 (defun shr-tag-ol (dom)
   (shr-ensure-paragraph)
-  (let ((shr-list-mode 1))
+  (let* ((attrs (dom-attributes dom))
+         (start-attr (alist-get 'start attrs))
+         ;; Start at 1 if there is no start attribute
+         ;; or if start can't be parsed as an integer.
+         (start-index (condition-case _
+                          (cl-parse-integer start-attr)
+                        (t 1)))
+         (shr-list-mode start-index))
     (shr-generic dom))
   (shr-ensure-paragraph))