[GRASS-SVN] r56285 - grass/trunk/raster/r.mapcalc

[svn_grass at osgeo.org]

Author: glynn
Date: 2013-05-17 07:45:18 -0700 (Fri, 17 May 2013)
New Revision: 56285

Modified:
   grass/trunk/raster/r.mapcalc/xmod.c
Log:
Fix potential integer overflow in modulo function


Modified: grass/trunk/raster/r.mapcalc/xmod.c
===================================================================
--- grass/trunk/raster/r.mapcalc/xmod.c	2013-05-17 12:44:56 UTC (rev 56284)
+++ grass/trunk/raster/r.mapcalc/xmod.c	2013-05-17 14:45:18 UTC (rev 56285)
@@ -1,4 +1,6 @@
 
+#include <math.h>
+
 #include <grass/gis.h>
 #include <grass/raster.h>
 #include "globals.h"
@@ -46,14 +48,10 @@
 		if (IS_NULL_F(&arg1[i]) || IS_NULL_F(&arg2[i]))
 		    SET_NULL_F(&res[i]);
 		else {
-		    int k;
-
 		    floating_point_exception = 0;
-		    k = (int)(arg1[i] / arg2[i]);
+		    res[i] = (FCELL) fmod(arg1[i], arg2[i]);
 		    if (floating_point_exception)
 			SET_NULL_F(&res[i]);
-		    else
-			res[i] = arg1[i] - k * arg2[i];
 		}
 	    }
 	    return 0;
@@ -68,14 +66,10 @@
 		if (IS_NULL_D(&arg1[i]) || IS_NULL_D(&arg2[i]))
 		    SET_NULL_D(&res[i]);
 		else {
-		    int k;
-
 		    floating_point_exception = 0;
-		    k = (int)(arg1[i] / arg2[i]);
+		    res[i] = (DCELL) fmod(arg1[i], arg2[i]);
 		    if (floating_point_exception)
 			SET_NULL_D(&res[i]);
-		    else
-			res[i] = arg1[i] - k * arg2[i];
 		}
 	    }
 	    return 0;