* process.c (rb_f_exec): should check whether prog is NULL.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@7165 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Mon Nov  1 11:46:19 2004  WATANABE Hirofumi  <eban@ruby-lang.org>
+
+	* process.c (rb_f_exec): should check whether prog is NULL.
+
 Mon Nov  1 09:37:19 2004  Kouhei Sutou  <kou@cozmixng.org>
 
 	* lib/rss/maker.rb: added entry point of RSS Maker.

process.c

@@ -1267,7 +1267,7 @@ rb_f_exec(argc, argv)
     else {
 	e.argc = argc;
 	e.argv = argv;
-	e.prog = RSTRING(prog)->ptr;
+	e.prog = prog ? RSTRING(prog)->ptr : 0;
     }
     rb_exec(&e);
     rb_sys_fail(e.prog);