Change gnutls-verify-error to be first-match

* doc/misc/url.texi (Customization): Describe the new user
option url-lastloc-privacy-level.

* lisp/net/eww.el (eww-render): Set url-current-lastloc to the
url we are rendering, to get the referer header right on
subsequent requests.

* lisp/url/url-http.el (url-http--get-referer): New function
to determine which referer to send, if any, considering the
users privacy settings and the target url we are visiting.
(url-http-referer): New variable keeping track of the referer
computed by url-http--get-referer
(url-http-create-request): Use url-http-referer instead of the
optional argument to set up the referer header.  Leave
checking of privacy settings to url-http--get-referer.
(url-http): Set up url-http-referer by using
url-http--get-referer.

* lisp/url/url-queue.el (url-queue): New struct member
context-buffer for keeping track of the context a queued job
started from.
(url-queue-retrieve): Store the current buffer in the queue
object.
(url-queue-start-retrieve): Make sure url-retrieve is called
in the context of the original buffer, if available.

* lisp/url/url-util.el (url-domain): New function to determine
the domain of a given URL.

* lisp/url/url-vars.el (url-current-lastloc): New variable to
keep track of the desired "last location" (referer header).
(url-lastloc-privacy-level): New custom setting for more
fine-grained control over how lastloc (referer) is sent to
servers (Bug#27012).

1 files changed, 29 insertions, 0 deletions

diff --git a/lisp/url/url-util.el b/lisp/url/url-util.el
index 85bfb65cb68..77e015068a3 100644
--- a/lisp/url/url-util.el
+++ b/lisp/url/url-util.el
@@ -627,6 +627,35 @@ Creates FILE and its parent directories if they do not exist."
          (error "Danger: `%s' is a symbolic link" file))
      (set-file-modes file #o0600))))
 
+(autoload 'dns-query "dns")
+
+(defvar url--domain-cache (make-hash-table :test 'equal :size 17)
+  "Cache to minimize dns lookups.")
+
+;;;###autoload
+(defun url-domain (url)
+  "Return the domain of the host of the url, or nil if url does
+not contain a registered name."
+  ;; Determining the domain of a name can not be done with simple
+  ;; textual manipulations.  a.b.c is either host a in domain b.c
+  ;; (www.google.com), or domain a.b.c with no separate host
+  ;; (bbc.co.uk).  Instead of guessing based on tld (which in any case
+  ;; may be inaccurate in the face of subdelegations), we look for
+  ;; domain delegations in DNS.
+  ;;
+  ;; Domain delegations change rarely enough that we won't bother with
+  ;; cache invalidation, I think.
+  (let* ((host-parts (split-string (url-host url) "\\."))
+         (result (gethash host-parts url--domain-cache 'not-found)))
+    (when (eq result 'not-found)
+      (setq result
+            (cl-loop for parts on host-parts
+                     for dom = (mapconcat #'identity parts ".")
+                     when (dns-query dom 'SOA)
+                     return dom))
+      (puthash host-parts result url--domain-cache))
+    result))
+
 (provide 'url-util)
 
 ;;; url-util.el ends here