From: Eli Zaretskii <eliz@gnu.org>
Date: Tue, 28 Jun 2016 16:03:43 +0000 (+0300)
Subject: Fix copying properties in 'format' when it produces padding
X-Git-Tag: emacs-26.0.90~1840^2~149
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=0644e6f56d2be82dd716478eb65e7b3c761d813d;p=emacs.git

Fix copying properties in 'format' when it produces padding

* src/textprop.c (extend_property_ranges): Correct range extension
when the new end is beyond the old end.  (Bug#23859)
---

diff --git a/src/textprop.c b/src/textprop.c
index c4e49d98ebc..aabd5671e76 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -2065,9 +2065,14 @@ extend_property_ranges (Lisp_Object list, Lisp_Object new_end)
 	  else
 	    XSETCDR (prev, XCDR (list));
 	}
-      else if (XINT (end) > max)
-	/* The end-point is past the end of the new string.  */
-	XSETCAR (XCDR (item), new_end);
+      else if (XINT (end) != max)
+	{
+	  /* Either the end-point is past the end of the new string,
+	     and we need to discard the properties past the new end,
+	     or the caller is extending the property range, and we
+	     should update the end-point to reflect that.  */
+	  XSETCAR (XCDR (item), new_end);
+	}
     }
 
   return head;