From 05cbca84fb81d290bc6b9a07f6cb5d2cb81111d5 Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 14 Jul 2009 07:13:11 +0000
Subject: * io.c (rb_io_initialize): check if the descriptor can be accessed  
 in the specified open mode.  [ruby-dev:38571]

git-svn-id: http://svn.ruby-lang.org/repos/ruby/trunk@24102 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 io.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

(limited to 'io.c')

diff --git a/io.c b/io.c
index 45c4a7321..4e576e710 100644
--- a/io.c
+++ b/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 defined(HAVE_FCNTL) && defined(F_GETFL)
+    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 (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);
-#endif
+    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;
-- 
cgit