Check for pending trigger events on far end when dropping an FK constraint.
When dropping a foreign key constraint with ALTER TABLE DROP CONSTRAINT,
we refuse the drop if there are any pending trigger events on the named
table; this ensures that we won't remove the pg_trigger row that will be
consulted by those events. But we should make the same check for the
referenced relation, else we might remove a due-to-be-referenced pg_trigger
row for that relation too, resulting in "could not find trigger NNN" or
"relation NNN has no triggers" errors at commit. Per bug #14431 from
Benjie Gillam. Back-patch to all supported branches.
Report: <20161124114911.6530.31200@wrigleys.postgresql.org>
Branch
------
REL9_4_STABLE
Details
-------
http://git.postgresql.org/pg/commitdiff/f7166ce243aec3f5df454377d81b67032d85f35c
Modified Files
--------------
src/backend/commands/tablecmds.c | 18 ++++++++++++++++++
src/test/regress/expected/foreign_key.out | 13 +++++++++++++
src/test/regress/sql/foreign_key.sql | 13 +++++++++++++
3 files changed, 44 insertions(+)