Prevent inlining a SQL function with multiple OUT parameters.

There were corner cases in which the planner would attempt to inline such
a function, which would result in a failure at runtime due to loss of
information about exactly what the result record type is.  Fix by disabling
inlining when the function's recorded result type is RECORD.  There might
be some sub-cases where inlining could still be allowed, but this is a
simple and backpatchable fix, so leave refinements for another day.
Per bug #5777 from Nate Carson.

Back-patch to all supported branches.  8.1 happens to avoid a core-dump
here, but it still does the wrong thing.

diff --git a/src/backend/executor/functions.c b/src/backend/executor/functions.c
index caff8d5d14b8c4729d6e25fe95e287c4d7bb6f6f..39e264cbe71f21311142a9d012dcfec58b052549 100644 (file)
--- a/src/backend/executor/functions.c
+++ b/src/backend/executor/functions.c
@@ -955,6 +955,11 @@ check_sql_fn_retval(Oid func_id, Oid rettype, List *queryTreeList,
                 * This can happen, for example, where the body of the function is
                 * 'SELECT func2()', where func2 has the same return type as the
                 * function that's calling it.
+                *
+                * XXX Note that if rettype is RECORD, the IsBinaryCoercible check
+                * will succeed for any composite restype.  For the moment we rely on
+                * runtime type checking to catch any discrepancy, but it'd be nice to
+                * do better at parse time.
                 */
                if (tlistlen == 1)
                {

diff --git a/src/backend/optimizer/util/clauses.c b/src/backend/optimizer/util/clauses.c
index 3268ec8979919af9d7b7d3894f222b7c0c11d98e..6390544d9fe591ed35c25a5967f1092bb93a282f 100644 (file)
--- a/src/backend/optimizer/util/clauses.c
+++ b/src/backend/optimizer/util/clauses.c
@@ -2668,6 +2668,10 @@ evaluate_function(Oid funcid, Oid result_type, List *args,
  * We must also beware of changing the volatility or strictness status of
  * functions by inlining them.
  *
+ * Also, at the moment we can't inline functions returning RECORD.  This
+ * doesn't work in the general case because it discards information such
+ * as OUT-parameter declarations.
+ *
  * Returns a simplified expression if successful, or NULL if cannot
  * simplify the function.
  */
@@ -2699,6 +2703,7 @@ inline_function(Oid funcid, Oid result_type, List *args,
        if (funcform->prolang != SQLlanguageId ||
                funcform->prosecdef ||
                funcform->proretset ||
+               funcform->prorettype == RECORDOID ||
                funcform->pronargs != list_length(args))
                return NULL;
 

diff --git a/src/test/regress/expected/rangefuncs.out b/src/test/regress/expected/rangefuncs.out
index 4fedc41ed86a739d3439ffd6a50c2f85fa582a33..843e24ef01dcdb29f6a84cfb23459abc2995e1e8 100644 (file)
--- a/src/test/regress/expected/rangefuncs.out
+++ b/src/test/regress/expected/rangefuncs.out
@@ -548,3 +548,23 @@ select t.a, t, t.a from foo1(10000) t limit 1;
 (1 row)
 
 drop function foo1(n integer);
+-- check handling of a SQL function with multiple OUT params (bug #5777)
+create or replace function foobar(out integer, out numeric) as
+$$ select (1, 2.1) $$ language sql;
+select * from foobar();
+ column1 | column2 
+---------+---------
+       1 |     2.1
+(1 row)
+
+create or replace function foobar(out integer, out numeric) as
+$$ select (1, 2) $$ language sql;
+select * from foobar();  -- fail
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned type integer at ordinal position 2, but query expects numeric.
+create or replace function foobar(out integer, out numeric) as
+$$ select (1, 2.1, 3) $$ language sql;
+select * from foobar();  -- fail
+ERROR:  function return row and query-specified return row do not match
+DETAIL:  Returned row contains 3 attributes, but query expects 2.
+drop function foobar();

diff --git a/src/test/regress/sql/rangefuncs.sql b/src/test/regress/sql/rangefuncs.sql
index baa56c7355ca2c9c5bf199634540cfa73e58dd61..b2753a0f55deb13fbf5596254dde8611e40716f3 100644 (file)
--- a/src/test/regress/sql/rangefuncs.sql
+++ b/src/test/regress/sql/rangefuncs.sql
@@ -274,3 +274,22 @@ reset work_mem;
 select t.a, t, t.a from foo1(10000) t limit 1;
 
 drop function foo1(n integer);
+
+-- check handling of a SQL function with multiple OUT params (bug #5777)
+
+create or replace function foobar(out integer, out numeric) as
+$$ select (1, 2.1) $$ language sql;
+
+select * from foobar();
+
+create or replace function foobar(out integer, out numeric) as
+$$ select (1, 2) $$ language sql;
+
+select * from foobar();  -- fail
+
+create or replace function foobar(out integer, out numeric) as
+$$ select (1, 2.1, 3) $$ language sql;
+
+select * from foobar();  -- fail
+
+drop function foobar();