bug#19130: 25.0.50; [PATCH] eww.el: Allow user to easily follow link in fresh eww buffer

[Andrey Kotlarski]

For eww-browse-url to be proper alternative in/as
browse-url-browser-function, it should implement opening in new buffer,
just like w3m-browse-url, w3-browse-url etc.  Following patch also
changes eww-follow-link to optionally make use of this.  Changed single
prefix to open in new eww buffer and double prefix to open externally,
because it seems like natural progression.

---
 lisp/ChangeLog  |  6 ++++++
 lisp/net/eww.el | 23 ++++++++++++++++-------
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 473a1f8..59afb2e 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,9 @@
+2014-11-20  Andrey Kotlarski  <m00naticus@gmail.com>
+
+       * net/eww.el (eww-browse-url): Optionally create new eww buffer.
+       (eww-follow-link): Follow in new buffer in case of prefix
+       argument, open externally with double prefix.
+
 2014-11-20  Eric S. Raymond  <esr@snark>
 
        * vc/vc-bzr.el, vc/vc-cvs.el, vc/vc-dav.el, vc/vc-git.el,
diff --git a/lisp/net/eww.el b/lisp/net/eww.el
index 6746668..9b6f779 100644
--- a/lisp/net/eww.el
+++ b/lisp/net/eww.el
@@ -624,10 +624,18 @@ the like."
   (setq buffer-read-only t))
 
 ;;;###autoload
-(defun eww-browse-url (url &optional _new-window)
-  (when (and (equal major-mode 'eww-mode)
-            (plist-get eww-data :url))
-    (eww-save-history))
+(defun eww-browse-url (url &optional new-window)
+  (cond (new-window
+         (let ((new-buffer "*eww*")
+               (num 0))
+           (while (get-buffer new-buffer)
+             (setq num (1+ num)
+                   new-buffer (format "*eww*<%d>" num)))
+           (switch-to-buffer new-buffer))
+         (eww-mode))
+        ((and (equal major-mode 'eww-mode)
+              (plist-get eww-data :url))
+         (eww-save-history)))
   (eww url))
 
 (defun eww-back-url ()
@@ -1238,7 +1246,8 @@ The browser to used is specified by the 
`shr-external-browser' variable."
 
 (defun eww-follow-link (&optional external mouse-event)
   "Browse the URL under point.
-If EXTERNAL, browse the URL using `shr-external-browser'."
+If EXTERNAL is single prefix, browse in new buffer.
+If EXTERNAL is double prefix, browse the URL using `shr-external-browser'."
   (interactive (list current-prefix-arg last-nonmenu-event))
   (mouse-set-point mouse-event)
   (let ((url (get-text-property (point) 'shr-url)))
@@ -1247,7 +1256,7 @@ If EXTERNAL, browse the URL using `shr-external-browser'."
       (message "No link under point"))
      ((string-match "^mailto:"; url)
       (browse-url-mail url))
-     (external
+     ((and (consp external) (< 4 (car external)))
       (funcall shr-external-browser url))
      ;; This is a #target url in the same page as the current one.
      ((and (url-target (url-generic-parse-url url))
@@ -1256,7 +1265,7 @@ If EXTERNAL, browse the URL using `shr-external-browser'."
       (eww-display-html 'utf-8 url (plist-get eww-data :url)
                        nil (current-buffer)))
      (t
-      (eww-browse-url url)))))
+      (eww-browse-url url external)))))
 
 (defun eww-same-page-p (url1 url2)
   "Return non-nil if both URLs represent the same page.
-- 
2.1.3