Thread: [COMMITTERS] pgsql: Fix interval_transform so it doesn't throw away non-no-opcasts.
[COMMITTERS] pgsql: Fix interval_transform so it doesn't throw away non-no-opcasts.
From
Tom Lane
Date:
Fix interval_transform so it doesn't throw away non-no-op casts. interval_transform() contained two separate bugs that caused it to sometimes mistakenly decide that a cast from interval to restricted interval is a no-op and throw it away. First, it was wrong to rely on dt.h's field type macros to have an ordering consistent with the field's significance; in one case they do not. This led to mistakenly treating YEAR as less significant than MONTH, so that a cast from INTERVAL MONTH to INTERVAL YEAR was incorrectly discarded. Second, fls(1<<k) produces k+1 not k, so comparing its output directly to SECOND was wrong. This led to supposing that a cast to INTERVAL MINUTE was really a cast to INTERVAL SECOND and so could be discarded. To fix, get rid of the use of fls(), and make a function based on intervaltypmodout to produce a field ID code adapted to the need here. Per bug #14479 from Piotr Stefaniak. Back-patch to 9.2 where transform functions were introduced, because this code was born broken. Discussion: https://postgr.es/m/20161227172307.10135.7747@wrigleys.postgresql.org Branch ------ REL9_6_STABLE Details ------- http://git.postgresql.org/pg/commitdiff/21e24eb9a0829fb40011055e389cbcf50670521d Modified Files -------------- src/backend/utils/adt/timestamp.c | 111 ++++++++++++++++++++++++--------- src/test/regress/expected/interval.out | 18 ++++++ src/test/regress/sql/interval.sql | 5 ++ 3 files changed, 105 insertions(+), 29 deletions(-)