Return -1 instead of EOF and set errno if the stream is not a real file stream.

diff --git a/libio/fileno.c b/libio/fileno.c
index 7ff93e6a8138839d825718280f4407b639e88ab6..92334f156429868a44664de746e2e6612085aec4 100644 (file)
--- 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);
 }