Fix obscure HTTP chunked parsing problem

* lisp/url/url-http.el
(url-http-chunked-encoding-after-change-function): Ensure that we
parse the entire initial chunked header as the length (bug#35658).

1 files changed, 6 insertions, 0 deletions

diff --git a/lisp/url/url-http.el b/lisp/url/url-http.el
index 03b863b69a8..48e29987a51 100644
--- a/lisp/url/url-http.el
+++ b/lisp/url/url-http.el
@@ -1084,6 +1084,12 @@ the end of the document."
                 ;; need to spin some more.
                 (url-http-debug "Did not see start of chunk @ %d!" (point))
                 (setq read-next-chunk nil))
+            ;; The data we got may have started in the middle of the
+            ;; initial chunk header, so move back to the start of the
+            ;; line and re-compute.
+            (when (= url-http-chunked-counter 0)
+              (beginning-of-line)
+              (looking-at regexp))
             (add-text-properties (match-beginning 0) (match-end 0)
                                  (list 'start-open t
                                        'end-open t