stdio: set and test stream orientation in low-level input function __srget_r

This allows to set and test orientation correctly if input is only
using macros from stdio.h.  Wide-char-oriented functions must call
__srefill_r directly.

Signed-off-by: Corinna Vinschen <corinna@vinschen.de>

newlib/libc/stdio/rget.c

@@ -39,6 +39,11 @@ __srget_r (struct _reent *ptr,
      we call __srefill_r so we may access the true read buffer. */
   CHECK_INIT(ptr, fp);
 
+  /* Have to set and check orientation here, otherwise the macros in
+     stdio.h never set it. */
+  if (ORIENT (fp, -1) != -1)
+    return EOF;
+
   if (__srefill_r (ptr, fp) == 0)
     {
       fp->_r--;