Subject: bug#41385: [PATCH] Show eww bookmarks buffer only if it's not empty

From: Stefan Kangas <[email-masked]>
Date: Tue, 19 May 2020 20:44:30 -0700

Lars Ingebrigtsen <[email-masked]> writes:

> I don't think this is an ideal way to fix this command -- using error
> handling to do control flow is usually the wrong thing to do, and it
> makes debugging difficult.  What if there's a real bug in
> eww-bookmark-prepare?
>
> Instead eww-list-bookmarks should just do the
>
>   (eww-read-bookmarks)
>   (unless eww-bookmarks
>     (user-error "No bookmarks are defined"))
>
> bit, I think.  It might mean rearranging some stuff in eww-next-bookmark
> etc, though.

Thanks, good point.  Does the attached patch look better?

Best regards,
Stefan Kangas
From 18a6aec0c8c24250fcd105d538bddcdf907c0e5c Mon Sep 17 00:00:00 2001
From: Stefan Kangas <[email-masked]>
Date: Tue, 19 May 2020 02:43:16 +0200
Subject: [PATCH] Show eww bookmarks buffer only if it's not empty

* lisp/net/eww.el (eww-list-bookmarks): Don't show buffer if there
are no bookmarks.  (Bug#41385)
(eww-bookmark-prepare): Move signalling an error if there are no
bookmarks from here...
(eww-read-bookmarks): ...to here.  Add new argument `error-out' to
control this.
(eww-next-bookmark, eww-previous-bookmark): Call `eww-read-bookmarks'.
---
 lisp/net/eww.el | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/lisp/net/eww.el b/lisp/net/eww.el
index a6c1abdbb1..84154c502d 100644
--- a/lisp/net/eww.el
+++ b/lisp/net/eww.el
@@ -1742,25 +1742,27 @@ eww-write-bookmarks
     (insert ";; Auto-generated file; don't edit -*- mode: lisp-data -*-\n")
     (pp eww-bookmarks (current-buffer))))
 
-(defun eww-read-bookmarks ()
+(defun eww-read-bookmarks (&optional error-out)
+  "Read bookmarks from `eww-bookmarks'.
+If ERROR-OUT, signal user-error if there are no bookmarks."
   (let ((file (expand-file-name "eww-bookmarks" eww-bookmarks-directory)))
     (setq eww-bookmarks
 	  (unless (zerop (or (file-attribute-size (file-attributes file)) 0))
 	    (with-temp-buffer
 	      (insert-file-contents file)
-	      (read (current-buffer)))))))
+	      (read (current-buffer)))))
+    (when (and error-out (not eww-bookmarks))
+      (user-error "No bookmarks are defined"))))
 
 ;;;###autoload
 (defun eww-list-bookmarks ()
   "Display the bookmarks."
   (interactive)
+  (eww-read-bookmarks t)
   (pop-to-buffer "*eww bookmarks*")
   (eww-bookmark-prepare))
 
 (defun eww-bookmark-prepare ()
-  (eww-read-bookmarks)
-  (unless eww-bookmarks
-    (user-error "No bookmarks are defined"))
   (set-buffer (get-buffer-create "*eww bookmarks*"))
   (eww-bookmark-mode)
   (let* ((width (/ (window-width) 2))
@@ -1828,6 +1830,7 @@ eww-next-bookmark
 	bookmark)
     (unless (get-buffer "*eww bookmarks*")
       (setq first t)
+      (eww-read-bookmarks t)
       (eww-bookmark-prepare))
     (with-current-buffer (get-buffer "*eww bookmarks*")
       (when (and (not first)
@@ -1846,6 +1849,7 @@ eww-previous-bookmark
 	bookmark)
     (unless (get-buffer "*eww bookmarks*")
       (setq first t)
+      (eww-read-bookmarks t)
       (eww-bookmark-prepare))
     (with-current-buffer (get-buffer "*eww bookmarks*")
       (if first
-- 
2.26.2