parse-datetime: fix debug message on lone year number
Input dates such as
date -d "Apr 11 22:59:00 2011"
are parsed as date (Apr 11, with default year 2016), then time, then a
number (2011). Based on the combination of previously seen tokens,
'digits_to_date_time' determines 2011 to be a year value.
This fixes the debug messages to correctly show the updated year.
Before:
$ date --debug -d 'Apr 11 22:59:00 2011'
date: parsed date part: (Y-M-D) 2016-04-11
date: parsed time part: 22:59:00
date: parsed number part: today/this/now
After:
$ ./src/date --debug -d 'Apr 11 22:59:00 2011'
date: parsed date part: (Y-M-D) 2016-04-11
date: parsed time part: 22:59:00
date: parsed number part: year: 2011
* lib/parse-datetime.y (struct parser_control): Add 'year_seen',
'debug_year_seen' member fields.
(digits_to_date_time): Update 'year_seen' as needed.
(debug_print_current_time): Inform about year updates.
(parse_datetime2): Initialize year_seen,debug_year_seen member fields.