From cb22d4a460cf9261f3e3f26750ce5f8520ba9680 Mon Sep 17 00:00:00 2001
From: Ulrich Drepper <drepper@redhat.com>
Date: Thu, 8 Jul 1999 11:55:34 +0000
Subject: [PATCH] Return -1 instead of EOF and set errno if the stream is not a
 real file stream.

---
 libio/fileno.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/libio/fileno.c b/libio/fileno.c
index 7ff93e6a813..92334f15642 100644
--- a/libio/fileno.c
+++ b/libio/fileno.c
@@ -32,8 +32,11 @@ fileno (fp)
 {
   CHECK_FILE (fp, EOF);
 
-  if (!(fp->_flags & _IO_IS_FILEBUF))
-    return EOF;
+  if (!(fp->_flags & _IO_IS_FILEBUF) || _IO_fileno (fp) < 0)
+    {
+      __set_errno (EBADF);
+      return -1;
+    }
 
   return _IO_fileno (fp);
 }
-- 
2.47.3