--- ray/src/common/fixargv0.c	2003/02/25 02:47:21	2.3
+++ ray/src/common/fixargv0.c	2016/03/20 16:36:17	2.7
@@ -1,29 +1,35 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: fixargv0.c,v 2.3 2003/02/25 02:47:21 greg Exp $";
+static const char	RCSid[] = "$Id: fixargv0.c,v 2.7 2016/03/20 16:36:17 schorsch Exp $";
 #endif
 /*
  * Fix argv[0] for DOS environments
  *
- *  External symbols declared in standard.h
+ *  External symbols declared in paths.h
  */
 
 #include "copyright.h"
 
+#include <ctype.h>
+#include <string.h>
 
-char *
+extern char *
 fixargv0(av0)			/* extract command name from full path */
 char  *av0;
 {
-	register char  *cp = av0;
+	register char  *cp = av0, *end = av0;
 
 	while (*cp) cp++;		/* start from end */
+	end = cp;
 	while (cp-- > av0)
 		switch (*cp) {		/* fix up command name */
 		case '.':			/* remove extension */
 			*cp = '\0';
+			end = cp;
 			continue;
 		case '\\':			/* remove directory */
-			return(cp+1);
+			/* make sure the original pointer remains the same */
+			memmove(av0, cp+1, end-cp);
+			break;
 		default:			/* convert to lower case */
 			*cp = tolower(*cp);
 			continue;