Re: [PATCH] Save and restore point explicitly in `notmuch-wash-toggle-invisible-action'.

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+From: Carl Worth <cworth@cworth.org>\r
+To: Dmitry Kurochkin <dmitry.kurochkin@gmail.com>, notmuch@notmuchmail.org\r
+Subject: Re: [PATCH] Save and restore point explicitly in\r
+       `notmuch-wash-toggle-invisible-action'.\r
+In-Reply-To: <1306164587-20326-1-git-send-email-dmitry.kurochkin@gmail.com>\r
+References: <1306090675-26982-1-git-send-email-dmitry.kurochkin@gmail.com>\r
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+Date: Tue, 24 May 2011 13:20:56 -0700\r
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+--=-=-=\r
+Content-Transfer-Encoding: quoted-printable\r
+\r
+On Mon, 23 May 2011 19:29:46 +0400, Dmitry Kurochkin <dmitry.kurochkin@gmai=\r
+l.com> wrote:\r
+> Before the change, save-excursion was used to save the point.\r
+> But the restored position is affected by buffer modifications,\r
+> which results in jumping cursor.  The patch saves and restores\r
+> point explicitly by using a variable instead of save-excursion.\r
+\r
+Dmitry,\r
+\r
+Thanks so much for the improvement to the button text! This will be a\r
+nice thing to add.\r
+\r
+But this patch confuses me. I can understand how a buffer-position\r
+variable can cause the cursor to jump. That's usually the kind of thing\r
+that can be fixed by switching from an integer position to a marker\r
+instead, (since markers are updated when the corresponding text is\r
+updated).\r
+\r
+But in this case, I don't see how:\r
+\r
+       (let ((old-point (point)))\r
+               ... code here ...\r
+         (goto-char old-point))\r
+\r
+is distinct from:\r
+\r
+       (save-excursion\r
+               ... code here ...\r
+        )\r
+\r
+except that save-excursion actually does the right thing in the case of\r
+abnormal exit (throw or error).\r
+\r
+Can you help me understand what I'm missing here?\r
+\r
+=2DCarl\r
+\r
+=2D-=20\r
+carl.d.worth@intel.com\r
+\r
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