From: Eli Zaretskii <eliz@gnu.org>
Date: Fri, 15 Jan 2016 15:36:47 +0000 (+0200)
Subject: Ensure positive number of glyphs for margins of positive width
X-Git-Tag: emacs-26.0.90~2313
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=a17bddeaa430715bf98f662a2c24ae5af50cc6b8;p=emacs.git

Ensure positive number of glyphs for margins of positive width

* src/dispnew.c (margin_glyphs_to_reserve): Always return a
positive value when a non-zero width of the marginal area was
requested.  (Bug#22356)

[This reapplies commit 740849fe986b62a839bce4bbf67d0036fc1be0b9,
which was inadvertently lost by merge commit
7823745acbe9b87eea2db4ef434e379fc903ec35.]
---

diff --git a/src/dispnew.c b/src/dispnew.c
index 9cf12f1a995..3a0532a693b 100644
--- a/src/dispnew.c
+++ b/src/dispnew.c
@@ -321,7 +321,9 @@ margin_glyphs_to_reserve (struct window *w, int total_glyphs, int margin)
       int width = w->total_cols;
       double d = max (0, margin);
       d = min (width / 2 - 1, d);
-      return (int) ((double) total_glyphs / width * d);
+      /* Since MARGIN is positive, we cannot possibly have less than
+	 one glyph for the marginal area.  */
+      return max (1, (int) ((double) total_glyphs / width * d));
     }
   return 0;
 }