* ascii.c (struct ascii_driver_ext): New member reported_error.

* ascii.c (struct ascii_driver_ext): New member reported_error.
(ascii_open_driver): Initialize reported_error.
(ascii_open_page): Initialize the rest of the ascii driver data
even if we fail to open the output file.  Fixes bug #21117.

* chart.c (chart_create): Initialize lp member.  Fixes crash if
chart initialization fails.

* html.c (html_open_driver): Don't free chart_file_name in error
case, since html_close_driver will do that.  Fixes crash if file
open fails.

* postscript.c (ps_close_driver): Don't try to write to file if
it's null.  Fixes crash if file open fails.