Fix plpgsql to re-look-up composite type names at need. Commit 4b93f5799 rearranged things in plpgsql to make it cope better with composite types changing underneath it intra-session. However, I failed to consider the case of a composite type being dropped and recreated entirely. In my defense, the previous coding didn't consider that possibility at all either --- but it would accidentally work so long as you didn't change the type's field list, because the built-at-compile-time list of component variables would then still match the type's new definition. The new coding, however, occasionally tries to re-look-up the type by OID, and then fails to find the dropped type.
To fix this, we need to save the TypeName struct, and then redo the type OID lookup from that. Of course that's expensive, so we don't want to do it every time we need the type OID. This can be fixed in the same way that 4b93f5799 dealt with changes to composite types' definitions: keep an eye on the type's typcache entry to see if its tupledesc has been invalidated. (Perhaps, at some point, this mechanism should be generalized so it can work for non-composite types too; but for now, plpgsql only tries to cope with intra-session redefinitions of composites.) I'm slightly hesitant to back-patch this into v11, because it changes the contents of struct PLpgSQL_type as well as the signature of plpgsql_build_datatype(), so in principle it could break code that is poking into the innards of plpgsql. However, the only popular extension of that ilk is pldebugger, and it doesn't seem to be affected. Since this is a regression for people who were relying on the old behavior, it seems worth taking the small risk of causing compatibility issues. Per bug #15913 from Daniel Fiori. Back-patch to v11 where 4b93f5799 came in. Discussion: https://postgr.es/m/15913-a7e112e16dedc...@postgresql.org Branch ------ REL_12_STABLE Details ------- https://git.postgresql.org/pg/commitdiff/a4504696e1ed04a112d312e0934dd324e90675e7 Modified Files -------------- src/backend/utils/cache/typcache.c | 10 ++ src/pl/plpgsql/src/expected/plpgsql_record.out | 29 ++++++ src/pl/plpgsql/src/pl_comp.c | 132 +++++++++++++++++++------ src/pl/plpgsql/src/pl_exec.c | 79 ++++++++++++++- src/pl/plpgsql/src/pl_gram.y | 22 +++-- src/pl/plpgsql/src/plpgsql.h | 14 ++- src/pl/plpgsql/src/sql/plpgsql_record.sql | 16 +++ 7 files changed, 265 insertions(+), 37 deletions(-)