Un-break whole-row Vars referencing domain-over-composite types.

In commit ec62cb0aa, I foolishly replaced ExecEvalWholeRowVar's
lookup_rowtype_tupdesc_domain call with just lookup_rowtype_tupdesc,
because I didn't see how a domain could be involved there, and
there were no regression test cases to jog my memory.  But the
existing code was correct, so revert that change and add a test
case showing why it's necessary.  (Note: per comment in struct
DatumTupleFields, it is correct to produce an output tuple that's
labeled with the base composite type, not the domain; hence just
blindly looking through the domain is correct here.)

Per bug #17515 from Dan Kubb.  Back-patch to v11 where domains over
composites became a thing.

Discussion: https://postgr.es/m/17515-a24737438363aca0@postgresql.org

diff --git a/src/backend/executor/execExprInterp.c b/src/backend/executor/execExprInterp.c
index 07b33531a6774a3df412a56a557ca90e77953234..0321a2d1c4b0a95f5fc4caa3d7bdb6ce312b96c9 100644 (file)
--- a/src/backend/executor/execExprInterp.c
+++ b/src/backend/executor/execExprInterp.c
@@ -3991,8 +3991,12 @@ ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
             * generates an INT4 NULL regardless of the dropped column type).
             * If we find a dropped column and cannot verify that case (1)
             * holds, we have to use the slow path to check (2) for each row.
+            *
+            * If vartype is a domain over composite, just look through that
+            * to the base composite type.
             */
-           var_tupdesc = lookup_rowtype_tupdesc(variable->vartype, -1);
+           var_tupdesc = lookup_rowtype_tupdesc_domain(variable->vartype,
+                                                       -1, false);
 
            slot_tupdesc = slot->tts_tupleDescriptor;
 

diff --git a/src/test/regress/expected/domain.out b/src/test/regress/expected/domain.out
index a6f033483154a1c0e942a74c74031d93927df523..93dc31ff1ca1f692d6c11231933ec8ac0690a3ad 100644 (file)
--- a/src/test/regress/expected/domain.out
+++ b/src/test/regress/expected/domain.out
@@ -283,6 +283,29 @@ Rules:
     ON DELETE TO dcomptable DO INSTEAD  UPDATE dcomptable SET d1.r = (dcomptable.d1).r - 1::double precision, d1.i = (dcomptable.d1).i + 1::double precision
   WHERE (dcomptable.d1).i > 0::double precision
 
+create function makedcomp(r float8, i float8) returns dcomptype
+as 'select row(r, i)' language sql;
+select makedcomp(1,2);
+ makedcomp 
+-----------
+ (1,2)
+(1 row)
+
+select makedcomp(2,1);  -- fail
+ERROR:  value for domain dcomptype violates check constraint "c1"
+select * from makedcomp(1,2) m;
+ r | i 
+---+---
+ 1 | 2
+(1 row)
+
+select m, m is not null from makedcomp(1,2) m;
+   m   | ?column? 
+-------+----------
+ (1,2) | t
+(1 row)
+
+drop function makedcomp(float8, float8);
 drop table dcomptable;
 drop type comptype cascade;
 NOTICE:  drop cascades to type dcomptype

diff --git a/src/test/regress/sql/domain.sql b/src/test/regress/sql/domain.sql
index 55c7cf74533fb312709bcac5729c432cf6337efb..d19e2bdf0c99b9db0ecd99ed51c3b2cba5ab1ac4 100644 (file)
--- a/src/test/regress/sql/domain.sql
+++ b/src/test/regress/sql/domain.sql
@@ -155,6 +155,15 @@ create rule silly as on delete to dcomptable do instead
   update dcomptable set d1.r = (d1).r - 1, d1.i = (d1).i + 1 where (d1).i > 0;
 \d+ dcomptable
 
+create function makedcomp(r float8, i float8) returns dcomptype
+as 'select row(r, i)' language sql;
+
+select makedcomp(1,2);
+select makedcomp(2,1);  -- fail
+select * from makedcomp(1,2) m;
+select m, m is not null from makedcomp(1,2) m;
+
+drop function makedcomp(float8, float8);
 drop table dcomptable;
 drop type comptype cascade;