# HG changeset patch
# User John W. Eaton <jwe@octave.org>
# Date 1207762302 14400
# Node ID 63e048203ed310a3e18d386585cc875a11762138
# Parent  8b77c3a5d87a3eb807afd10130ac0b5fac93b255
changeset:   7800:9828eda04f24
tag:         tip
user:        Michael Goffioul <michael.goffioul@gmail.com>
date:        Wed Apr 09 15:50:56 2008 +0200
files:       liboctave/ChangeLog liboctave/lo-mappers.cc
description:
Fix xround implementation under Win32 (use gnulib version).

diff --git a/liboctave/ChangeLog b/liboctave/ChangeLog
--- a/liboctave/ChangeLog
+++ b/liboctave/ChangeLog
@@ -1,5 +1,8 @@
 2008-04-09  Michael Goffioul  <michael.goffioul@gmail.com>
 
+	* lo-mappers.cc (xround): Avoid floating-point overflow when input
+	value is equal to bitmax implementation taken from gnulib).
+
 	* file-stat.cc (file_stat::update_internal): Do not strip trailing
 	file separator when path length is equal to 1 (handle case '\') under
 	__WIN32__ platforms.
diff --git a/liboctave/lo-mappers.cc b/liboctave/lo-mappers.cc
--- a/liboctave/lo-mappers.cc
+++ b/liboctave/lo-mappers.cc
@@ -75,7 +75,24 @@
 #if defined (HAVE_ROUND)
   return round (x);
 #else
-  return x > 0 ? floor (x + 0.5) : ceil (x - 0.5);
+  if (x >= 0)
+    {
+      double y = floor (x);
+
+      if ((x - y) >= 0.5)
+	y += 1.0;
+
+      return y;
+    }
+  else
+    {
+      double y = ceil (x);
+
+      if ((y - x) >= 0.5)
+	y -= 1.0;
+
+      return y;
+    }
 #endif
 }