e0df80828a
Commit 2ed8f9a01 intended to institute a policy that if a RangeTblFunction has a coldeflist, then the function return type is certainly RECORD, and we should use the coldeflist as the source of truth about what the columns of the record type are. When the original function has been folded to a constant, inspection of the constant might give a different answer. This situation will lead to a tuple-type-mismatch error at execution, but up until that point we need to consistently believe the coldeflist, or we'll have problems from different bits of code reaching different conclusions. expandRTE didn't get that memo though, and would try to produce a tupdesc based on the constant in this situation, leading to an assertion failure. (Desultory testing suggests that non-assert builds often manage to give the expected error, although I also saw a "cache lookup failed for type 0" error, and it seems at least possible that a crash could happen.) Some other callers of get_expr_result_type and get_expr_result_tupdesc were also being incautious about this. While none of them seem to have actual bugs, they're working harder than necessary in this case, besides which it seems safest to have an explicit policy of not using those functions on an RTE with a coldeflist. Adjust the code accordingly, and add commentary to funcapi.c about this policy. Also fix an obsolete comment that claimed "get_expr_result_type() doesn't know how to extract type info from a RECORD constant". That hasn't been true since commit d57534740. Per bug #18422 from Alexander Lakhin. As with the previous commit, back-patch to all supported branches. Discussion: https://postgr.es/m/18422-89ca86c8eac5246d@postgresql.org
PostgreSQL Database Management System
This directory contains the source code distribution of the PostgreSQL database management system.
PostgreSQL is an advanced object-relational database management system that supports an extended subset of the SQL standard, including transactions, foreign keys, subqueries, triggers, user-defined types and functions. This distribution also contains C language bindings.
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