* io.c (rb_io_initialize): check if the descriptor can be accessed

in the specified open mode.  [ruby-dev:38571]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@24102 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Tue Jul 14 16:13:04 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (rb_io_initialize): check if the descriptor can be accessed
+	  in the specified open mode.  [ruby-dev:38571]
+
 Tue Jul 14 09:26:14 2009  Hidetoshi NAGAI  <nagai@ai.kyutech.ac.jp>
 
 	* ext/tk/lib/multi-tk.rb: Long-term-callback support isn't stable yet.

io.c

@@ -6342,7 +6342,11 @@ rb_io_initialize(int argc, VALUE *argv, VALUE io)
     int fd, fmode, oflags = O_RDONLY;
     convconfig_t convconfig;
     VALUE opt;
+#if defined(HAVE_FCNTL) && defined(F_GETFL)
+    int ofmode;
+#else
     struct stat st;
+#endif
 
     rb_secure(4);
 
@@ -6351,15 +6355,23 @@ 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)
-        oflags = fcntl(fd, F_GETFL);
-        if (oflags == -1) rb_sys_fail(0);
-        fmode = rb_io_oflags_fmode(oflags);
+    oflags = fcntl(fd, F_GETFL);
+    if (oflags == -1) rb_sys_fail(0);
+#else
+    if (fstat(fd, &st) == -1) rb_sys_fail(0);
 #endif
+    UPDATE_MAXFD(fd);
+#if defined(HAVE_FCNTL) && defined(F_GETFL)
+    ofmode = rb_io_oflags_fmode(oflags);
+    if (NIL_P(vmode)) {
+	fmode = ofmode;
     }
+    else if ((~ofmode & fmode) & FMODE_READWRITE) {
+	VALUE error = INT2FIX(EINVAL);
+	rb_exc_raise(rb_class_new_instance(1, &error, rb_eSystemCallError));
+    }
+#endif
     MakeOpenFile(io, fp);
     fp->fd = fd;
     fp->mode = fmode;

test/ruby/test_io.rb

@@ -1379,6 +1379,9 @@ class TestIO < Test::Unit::TestCase
 
     fd = IO.sysopen(t.path, "w")
     assert_kind_of(Integer, fd)
+    %w[r r+ w+ a+].each do |mode|
+      assert_raise(Errno::EINVAL, '[ruby-dev:38571]') {IO.new(fd, mode)}
+    end
     f = IO.new(fd, "w")
     f.write("FOO\n")
     f.close