database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-08-14 02:22:38 +03:00
Code Activity

Fix handling of BC years in to_date/to_timestamp.

Browse Source 
Previously, a conversion such as
	to_date('-44-02-01','YYYY-MM-DD')
would result in '0045-02-01 BC', as the code attempted to interpret
the negative year as BC, but failed to apply the correction needed
for our internal handling of BC years.  Fix the off-by-one problem.

Also, arrange for the combination of a negative year and an
explicit "BC" marker to cancel out and produce AD.  This is how
the negative-century case works, so it seems sane to do likewise.

Continue to read "year 0000" as 1 BC.  Oracle would throw an error,
but we've accepted that case for a long time so I'm hesitant to
change it in a back-patch.

Per bug #16419 from Saeed Hubaishan.  Back-patch to all supported
branches.

Dar Alathar-Yemen and Tom Lane

Discussion: https://postgr.es/m/16419-d8d9db0a7553f01b@postgresql.org
This commit is contained in:
Tom Lane
2020-09-30 15:40:23 -04:00
parent 40a8fb1e0f
commit 4857e6fe16
4 changed files with 67 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

7
src/backend/utils/adt/formatting.c
View File

@@ -3678,8 +3678,11 @@ do_to_timestamp(text *date_txt, text *fmt,
/* If a 4-digit year is provided, we use that and ignore CC. */
{
tm->tm_year = tmfc.year;
if (tmfc.bc && tm->tm_year > 0)
tm->tm_year = -(tm->tm_year - 1);
if (tmfc.bc)
tm->tm_year = -tm->tm_year;
/* correct for our representation of BC years */
if (tm->tm_year < 0)
tm->tm_year++;
}
}
else if (tmfc.cc) /* use first year of century */