Fix confusion about the return rowtype of SQL-language procedures.

There is a very ancient hack in check_sql_fn_retval that allows a
single SELECT targetlist entry of composite type to be taken as
supplying all the output columns of a function returning composite.
(This is grotty and fundamentally ambiguous, but it's really hard
to do nested composite-returning functions without it.)

As far as I know, that doesn't cause any problems in ordinary
functions.  It's disastrous for procedures however.  All procedures
that have any output parameters are labeled with prorettype RECORD,
and the CALL code expects it will get back a record with one column
per output parameter, regardless of whether any of those parameters
is composite.  Doing something else leads to an assertion failure
or core dump.

This is simple enough to fix: we just need to not apply that rule
when considering procedures.  However, that requires adding another
argument to check_sql_fn_retval, which at least in principle might be
getting called by external callers.  Therefore, in the back branches
convert check_sql_fn_retval into an ABI-preserving wrapper around a
new function check_sql_fn_retval_ext.

Per report from Yahor Yuzefovich.  This has been broken since we
implemented procedures, so back-patch to all supported branches.

Discussion: https://postgr.es/m/CABz5gWHSjj2df6uG0NRiDhZ_Uz=Y8t0FJP-_SVSsRsnrQT76Gg@mail.gmail.com

diff --git a/src/backend/catalog/pg_proc.c b/src/backend/catalog/pg_proc.c
index ab2b6ca1487b59ea08a20ccddf48a942702b57fc..e6c6001f3996db8684158f9f67e682cbb12d3bca 100644 (file)
--- a/src/backend/catalog/pg_proc.c
+++ b/src/backend/catalog/pg_proc.c
@@ -959,6 +959,7 @@ fmgr_sql_validator(PG_FUNCTION_ARGS)
 
                        (void) check_sql_fn_retval(querytree_list,
                                                                           rettype, rettupdesc,
+                                                                          proc->prokind,
                                                                           false, NULL);
                }
 

diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index a4b6e1effdb2b244b434407d51129f979aaa00e4..6e926ef4eed1dd4667810217a8fb7f0f24af4442 100644 (file)
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -746,6 +746,7 @@ init_sql_fcache(FunctionCallInfo fcinfo, Oid collation, bool lazyEvalOK)
        fcache->returnsTuple = check_sql_fn_retval(queryTree_list,
                                                                                           rettype,
                                                                                           rettupdesc,
+                                                                                          procedureStruct->prokind,
                                                                                           false,
                                                                                           &resulttlist);
 
@@ -1606,6 +1607,7 @@ check_sql_fn_statements(List *queryTreeLists)
 bool
 check_sql_fn_retval(List *queryTreeLists,
                                        Oid rettype, TupleDesc rettupdesc,
+                                       char prokind,
                                        bool insertDroppedCols,
                                        List **resultTargetList)
 {
@@ -1625,7 +1627,7 @@ check_sql_fn_retval(List *queryTreeLists,
 
        /*
         * If it's declared to return VOID, we don't care what's in the function.
-        * (This takes care of the procedure case, as well.)
+        * (This takes care of procedures with no output parameters, as well.)
         */
        if (rettype == VOIDOID)
                return false;
@@ -1780,8 +1782,13 @@ check_sql_fn_retval(List *queryTreeLists,
                 * or not the record type really matches.  For the moment we rely on
                 * runtime type checking to catch any discrepancy, but it'd be nice to
                 * do better at parse time.
+                *
+                * We must *not* do this for a procedure, however.  Procedures with
+                * output parameter(s) have rettype RECORD, and the CALL code expects
+                * to get results corresponding to the list of output parameters, even
+                * when there's just one parameter that's composite.
                 */
-               if (tlistlen == 1)
+               if (tlistlen == 1 && prokind != PROKIND_PROCEDURE)
                {
                        TargetEntry *tle = (TargetEntry *) linitial(tlist);
 

diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 62de0225fe64ea2946283875977fa0b715f2d8de..d09dde210f641e55dde308c04773ca9321d746bf 100644 (file)
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -4707,6 +4707,7 @@ inline_function(Oid funcid, Oid result_type, Oid result_collid,
        querytree_list = list_make1(querytree);
        if (check_sql_fn_retval(list_make1(querytree_list),
                                                        result_type, rettupdesc,
+                                                       funcform->prokind,
                                                        false, NULL))
                goto fail;                              /* reject whole-tuple-result cases */
 
@@ -5253,6 +5254,7 @@ inline_set_returning_function(PlannerInfo *root, RangeTblEntry *rte)
         */
        if (!check_sql_fn_retval(list_make1(querytree_list),
                                                         fexpr->funcresulttype, rettupdesc,
+                                                        funcform->prokind,
                                                         true, NULL) &&
                (functypclass == TYPEFUNC_COMPOSITE ||
                 functypclass == TYPEFUNC_COMPOSITE_DOMAIN ||

diff --git a/src/include/executor/functions.h b/src/include/executor/functions.h
index 1590d1efa615d971d48c4f9e3b38b0cd54a5e5af..27f948c6f52eb42615b02f3dd7d5d43fc253eed0 100644 (file)
--- a/src/include/executor/functions.h
+++ b/src/include/executor/functions.h
@@ -47,6 +47,7 @@ extern void check_sql_fn_statements(List *queryTreeLists);
 
 extern bool check_sql_fn_retval(List *queryTreeLists,
                                                                Oid rettype, TupleDesc rettupdesc,
+                                                               char prokind,
                                                                bool insertDroppedCols,
                                                                List **resultTargetList);
 

diff --git a/src/test/regress/expected/create_procedure.out b/src/test/regress/expected/create_procedure.out
index f2a677fa552a899c25bee2781b93d9f6c74cba5b..6ab09d7ec89dfaa8285cb00b4785a660397324bf 100644 (file)
--- a/src/test/regress/expected/create_procedure.out
+++ b/src/test/regress/expected/create_procedure.out
@@ -148,7 +148,19 @@ CALL ptest4a(a, b);  -- error, not supported
 $$;
 ERROR:  calling procedures with output arguments is not supported in SQL functions
 CONTEXT:  SQL function "ptest4b"
-DROP PROCEDURE ptest4a;
+-- we used to get confused by a single output argument that is composite
+CREATE PROCEDURE ptest4c(INOUT comp int8_tbl)
+LANGUAGE SQL
+AS $$
+SELECT ROW(1, 2);
+$$;
+CALL ptest4c(NULL);
+ comp  
+-------
+ (1,2)
+(1 row)
+
+DROP PROCEDURE ptest4a, ptest4c;
 -- named and default parameters
 CREATE OR REPLACE PROCEDURE ptest5(a int, b text, c int default 100)
 LANGUAGE SQL

diff --git a/src/test/regress/sql/create_procedure.sql b/src/test/regress/sql/create_procedure.sql
index 35b872779efc1608b3421800ba1239e90e20937e..012cdf36283facdb52c8d4d55ae83c755ba51520 100644 (file)
--- a/src/test/regress/sql/create_procedure.sql
+++ b/src/test/regress/sql/create_procedure.sql
@@ -90,7 +90,16 @@ AS $$
 CALL ptest4a(a, b);  -- error, not supported
 $$;
 
-DROP PROCEDURE ptest4a;
+-- we used to get confused by a single output argument that is composite
+CREATE PROCEDURE ptest4c(INOUT comp int8_tbl)
+LANGUAGE SQL
+AS $$
+SELECT ROW(1, 2);
+$$;
+
+CALL ptest4c(NULL);
+
+DROP PROCEDURE ptest4a, ptest4c;
 
 
 -- named and default parameters