* io.c (rb_io_initialize): check fd validity. [ruby-dev:36646]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@20990 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,7 @@
+Thu Dec 25 17:06:13 2008  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (rb_io_initialize): check fd validity.  [ruby-dev:36646]
+
 Thu Dec 25 16:23:31 2008  Tanaka Akira  <akr@fsij.org>
 
 	* io.c (flush_before_seek): check io_fflush result.

io.c

@@ -5928,6 +5928,7 @@ rb_io_initialize(int argc, VALUE *argv, VALUE io)
     int fd, fmode, oflags = O_RDONLY;
     convconfig_t convconfig;
     VALUE opt;
+    struct stat st;
 
     rb_secure(4);
 
@@ -5936,6 +5937,7 @@ rb_io_initialize(int argc, VALUE *argv, VALUE io)
     rb_io_extract_modeenc(&vmode, 0, opt, &oflags, &fmode, &convconfig);
 
     fd = NUM2INT(fnum);
+    if (fstat(fd, &st) == -1) rb_sys_fail(0);
     UPDATE_MAXFD(fd);
     if (NIL_P(vmode)) {
 #if defined(HAVE_FCNTL) && defined(F_GETFL)