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author | Tom Lane <tgl@sss.pgh.pa.us> | 2019-12-12 12:30:44 -0500 |
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committer | Tom Lane <tgl@sss.pgh.pa.us> | 2019-12-12 12:30:44 -0500 |
commit | 07c4b6ac7d6e467f9db681772b5d5101144fcfe7 (patch) | |
tree | 457c55e4dda6a6e7d2229d3d42a2c2cbcf956fc0 /src/backend/utils/adt/timestamp.c | |
parent | 73355634959bc011508a24f0e344c6f6fddf419e (diff) | |
download | postgresql-07c4b6ac7d6e467f9db681772b5d5101144fcfe7.tar.gz postgresql-07c4b6ac7d6e467f9db681772b5d5101144fcfe7.zip |
Fix EXTRACT(ISOYEAR FROM timestamp) for years BC.
The test cases added by commit 26ae3aa80 exposed an old oversight in
timestamp[tz]_part: they didn't correct the result of date2isoyear()
for BC years, so that we produced an off-by-one answer for such years.
Fix that, and back-patch to all supported branches.
Discussion: https://postgr.es/m/SG2PR06MB37762CAE45DB0F6CA7001EA9B6550@SG2PR06MB3776.apcprd06.prod.outlook.com
Diffstat (limited to 'src/backend/utils/adt/timestamp.c')
-rw-r--r-- | src/backend/utils/adt/timestamp.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c index 9151d347ed9..666452d81ef 100644 --- a/src/backend/utils/adt/timestamp.c +++ b/src/backend/utils/adt/timestamp.c @@ -4359,6 +4359,7 @@ date2isoweek(int year, int mon, int mday) /* date2isoyear() * * Returns ISO 8601 year number. + * Note: zero or negative results follow the year-zero-exists convention. */ int date2isoyear(int year, int mon, int mday) @@ -4633,6 +4634,9 @@ timestamp_part(PG_FUNCTION_ARGS) case DTK_ISOYEAR: result = date2isoyear(tm->tm_year, tm->tm_mon, tm->tm_mday); + /* Adjust BC years */ + if (result <= 0) + result -= 1; break; case DTK_DOW: @@ -4829,6 +4833,9 @@ timestamptz_part(PG_FUNCTION_ARGS) case DTK_ISOYEAR: result = date2isoyear(tm->tm_year, tm->tm_mon, tm->tm_mday); + /* Adjust BC years */ + if (result <= 0) + result -= 1; break; case DTK_DOW: |