From: Eli Zaretskii <eliz@gnu.org>
Date: Fri, 6 Dec 2019 13:29:20 +0000 (+0200)
Subject: Fix set-marker when the position is larger than the largest buffer
X-Git-Tag: emacs-27.0.90~425
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=1171fa32ca0bc7682b9fdc93babebc4c4feed104;p=emacs.git

Fix set-marker when the position is larger than the largest buffer

* src/marker.c (set_marker_internal): Handle the case where
POSITION is beyond PTRDIFF_MAX, which can happen if Emacs was
built --with-wide-int.  Bug uncovered by the recently added
overlay tests.
---

diff --git a/src/marker.c b/src/marker.c
index 0b2e1bf5c6b..6358bc3bf79 100644
--- a/src/marker.c
+++ b/src/marker.c
@@ -529,7 +529,18 @@ set_marker_internal (Lisp_Object marker, Lisp_Object position,
 	 don't want to call buf_charpos_to_bytepos if POSITION
 	 is a marker and so we know the bytepos already.  */
       if (FIXNUMP (position))
-	charpos = XFIXNUM (position), bytepos = -1;
+	{
+#if EMACS_INT_MAX > PTRDIFF_MAX
+	  /* A --with-wide-int build.  */
+	  EMACS_INT cpos = XFIXNUM (position);
+	  if (cpos > PTRDIFF_MAX)
+	    cpos = PTRDIFF_MAX;
+	  charpos = cpos;
+	  bytepos = -1;
+#else
+	  charpos = XFIXNUM (position), bytepos = -1;
+#endif
+	}
       else if (MARKERP (position))
 	{
 	  charpos = XMARKER (position)->charpos;