diff options
Diffstat (limited to 'libio/wfileops.c')
| -rw-r--r-- | libio/wfileops.c | 32 |
1 files changed, 29 insertions, 3 deletions
diff --git a/libio/wfileops.c b/libio/wfileops.c index e88c0654e5..92d1a08190 100644 --- a/libio/wfileops.c +++ b/libio/wfileops.c @@ -458,7 +458,28 @@ _IO_wfile_seekoff (fp, offset, dir, mode) == fp->_wide_data->_IO_write_ptr)); if (mode == 0) - dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */ + { + /* XXX For wide stream with backup store it is not very + reasonable to determine the offset. The pushed-back + character might require a state change and we need not be + able to compute the initial state by reverse transformation + since there is no guarantee of symmetry. So we don't even + try and return an error. */ + if (_IO_in_backup (fp)) + { + if (fp->_wide_data->_IO_read_ptr < fp->_wide_data->_IO_read_end) + { + __set_errno (EINVAL); + return -1; + } + + /* There is no more data in the backup buffer. We can + switch back. */ + _IO_switch_to_main_wget_area (fp); + } + + dir = _IO_seek_cur, offset = 0; /* Don't move any pointers. */ + } /* Flush unwritten characters. (This may do an unneeded write if we seek within the buffer. @@ -466,7 +487,7 @@ _IO_wfile_seekoff (fp, offset, dir, mode) egptr to ptr. That can't be done in the current design, which assumes file_ptr() is eGptr. Anyway, since we probably end up flushing when we close(), it doesn't make much difference.) - FIXME: simulate mem-papped files. */ + FIXME: simulate mem-mapped files. */ if (fp->_wide_data->_IO_write_ptr > fp->_wide_data->_IO_write_base || _IO_in_put_mode (fp)) @@ -509,12 +530,13 @@ _IO_wfile_seekoff (fp, offset, dir, mode) { int nread; - delta = fp->_wide_data->_IO_read_ptr - fp->_wide_data->_IO_read_end; + delta = fp->_wide_data->_IO_read_ptr - fp->_wide_data->_IO_read_base; fp->_wide_data->_IO_state = fp->_wide_data->_IO_last_state; nread = (*cv->__codecvt_do_length) (cv, &fp->_wide_data->_IO_state, fp->_IO_read_base, fp->_IO_read_end, delta); fp->_IO_read_ptr = fp->_IO_read_base + nread; + fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_read_ptr; offset -= fp->_IO_read_end - fp->_IO_read_base - nread; } @@ -651,6 +673,10 @@ _IO_wfile_seekoff (fp, offset, dir, mode) fp->_offset = result; _IO_setg (fp, fp->_IO_buf_base, fp->_IO_buf_base, fp->_IO_buf_base); _IO_setp (fp, fp->_IO_buf_base, fp->_IO_buf_base); + _IO_wsetg (fp, fp->_wide_data->_IO_buf_base, + fp->_wide_data->_IO_buf_base, fp->_wide_data->_IO_buf_base); + _IO_wsetp (fp, fp->_wide_data->_IO_buf_base, + fp->_wide_data->_IO_buf_base); } return result; |