mg - debian bug #658539

[Mark Lumsden]

Fix an outstanding debian bug:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=658539

ok?

-lum

Index: fileio.c
===================================================================
RCS file: /cvs/src/usr.bin/mg/fileio.c,v
retrieving revision 1.93
diff -u -p -r1.93 fileio.c
--- fileio.c    18 Jun 2012 07:14:55 -0000      1.93
+++ fileio.c    3 Jul 2012 11:24:06 -0000
@@ -701,7 +701,8 @@ expandtilde(const char *fn)
        struct passwd   *pw;
        struct stat      statbuf;
        const char      *cp;
-       char             user[LOGIN_NAME_MAX], path[NFILEN], *ret;
+       char             user[LOGIN_NAME_MAX], path[NFILEN];
+       char            *ret, *un;
        size_t           ulen, plen;
 
        path[0] = '\0';
@@ -720,9 +721,12 @@ expandtilde(const char *fn)
                        return (NULL);
                return(ret);
        }
-       if (ulen == 0) /* ~/ or ~ */
-               (void)strlcpy(user, getlogin(), sizeof(user));
-       else { /* ~user/ or ~user */
+       if (ulen == 0) { /* ~/ or ~ */
+               if ((un = getlogin()) != NULL)
+                       (void)strlcpy(user, un, sizeof(user));
+               else
+                       user[0] = '\0';
+       } else { /* ~user/ or ~user */
                memcpy(user, &fn[1], ulen);
                user[ulen] = '\0';
        }