1 files changed, 90 insertions, 2 deletions

diff --git a/libio/wfileops.c b/libio/wfileops.c
index 92d1a08190..35d201b939 100644
--- a/libio/wfileops.c
+++ b/libio/wfileops.c
@@ -143,7 +143,7 @@ _IO_wfile_underflow (fp)
   int tries;
   const char *read_ptr_copy;
 
-  if (fp->_flags & _IO_NO_READS)
+  if (__builtin_expect (fp->_flags & _IO_NO_READS, 0))
     {
       fp->_flags |= _IO_ERR_SEEN;
       __set_errno (EBADF);
@@ -161,10 +161,12 @@ _IO_wfile_underflow (fp)
       const char *read_stop = (const char *) fp->_IO_read_ptr;
 
       fp->_wide_data->_IO_last_state = fp->_wide_data->_IO_state;
+      fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr =
+	fp->_wide_data->_IO_buf_base;
       status = (*cd->__codecvt_do_in) (cd, &fp->_wide_data->_IO_state,
 				       fp->_IO_read_ptr, fp->_IO_read_end,
 				       &read_stop,
-				       fp->_wide_data->_IO_read_end,
+				       fp->_wide_data->_IO_read_ptr,
 				       fp->_wide_data->_IO_buf_end,
 				       &fp->_wide_data->_IO_read_end);
 
@@ -306,6 +308,67 @@ _IO_wfile_underflow (fp)
 }
 
 
+static wint_t
+_IO_wfile_underflow_mmap (_IO_FILE *fp)
+{
+  struct _IO_codecvt *cd;
+  enum __codecvt_result status;
+
+  if (__builtin_expect (fp->_flags & _IO_NO_READS, 0))
+    {
+      fp->_flags |= _IO_ERR_SEEN;
+      __set_errno (EBADF);
+      return WEOF;
+    }
+  if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
+    return *fp->_wide_data->_IO_read_ptr;
+
+  cd = fp->_codecvt;
+
+  /* Maybe there is something left in the external buffer.  */
+  if (fp->_IO_read_ptr < fp->_IO_read_end)
+    {
+      /* There is more in the external.  Convert it.  */
+      const char *read_stop = (const char *) fp->_IO_read_ptr;
+
+      if (fp->_wide_data->_IO_buf_base == NULL)
+	{
+	  /* Maybe we already have a push back pointer.  */
+	  if (fp->_wide_data->_IO_save_base != NULL)
+	    {
+	      free (fp->_wide_data->_IO_save_base);
+	      fp->_flags &= ~_IO_IN_BACKUP;
+	    }
+	  _IO_wdoallocbuf (fp);
+	}
+
+      fp->_wide_data->_IO_last_state = fp->_wide_data->_IO_state;
+      fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr =
+	fp->_wide_data->_IO_buf_base;
+      status = (*cd->__codecvt_do_in) (cd, &fp->_wide_data->_IO_state,
+				       fp->_IO_read_ptr, fp->_IO_read_end,
+				       &read_stop,
+				       fp->_wide_data->_IO_read_ptr,
+				       fp->_wide_data->_IO_buf_end,
+				       &fp->_wide_data->_IO_read_end);
+
+      fp->_IO_read_ptr = (char *) read_stop;
+
+      /* If we managed to generate some text return the next character.  */
+      if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end)
+	return *fp->_wide_data->_IO_read_ptr;
+
+      /* There is some garbage at the end of the file.  */
+      __set_errno (EILSEQ);
+      fp->_flags |= _IO_ERR_SEEN;
+      return WEOF;
+    }
+
+  fp->_flags |= _IO_EOF_SEEN;
+  return WEOF;
+}
+
+
 wint_t
 _IO_wfile_overflow (f, wch)
      _IO_FILE *f;
@@ -789,3 +852,28 @@ struct _IO_jump_t _IO_wfile_jumps =
   JUMP_INIT(showmanyc, _IO_default_showmanyc),
   JUMP_INIT(imbue, _IO_default_imbue)
 };
+
+
+struct _IO_jump_t _IO_wfile_jumps_mmap =
+{
+  JUMP_INIT_DUMMY,
+  JUMP_INIT(finish, _IO_new_file_finish),
+  JUMP_INIT(overflow, (_IO_overflow_t) _IO_wfile_overflow),
+  JUMP_INIT(underflow, (_IO_underflow_t) _IO_wfile_underflow_mmap),
+  JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
+  JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
+  JUMP_INIT(xsputn, _IO_wfile_xsputn),
+  JUMP_INIT(xsgetn, _IO_file_xsgetn),
+  JUMP_INIT(seekoff, _IO_wfile_seekoff),
+  JUMP_INIT(seekpos, _IO_default_seekpos),
+  JUMP_INIT(setbuf, _IO_new_file_setbuf),
+  JUMP_INIT(sync, (_IO_sync_t) _IO_wfile_sync),
+  JUMP_INIT(doallocate, _IO_wfile_doallocate),
+  JUMP_INIT(read, _IO_file_read),
+  JUMP_INIT(write, _IO_new_file_write),
+  JUMP_INIT(seek, _IO_file_seek),
+  JUMP_INIT(close, _IO_file_close_mmap),
+  JUMP_INIT(stat, _IO_file_stat),
+  JUMP_INIT(showmanyc, _IO_default_showmanyc),
+  JUMP_INIT(imbue, _IO_default_imbue)
+};