postgres.git / summary / log / commit / refs
commit 112fdb3528465cc14a2f1dff3dc27f100326d885
Author: Andrew Dunstan <andrew@dunslane.net>
Date: Wed Apr 13 14:26:38 2022 +0000
Fix finalization for json_objectagg and friends
Commit f4fb45d15c misguidedly tried to free some state during aggregate
finalization for json_objectagg. This resulted in attempts to access
freed memory, especially when the function is used as a window function.
Commit 4eb9798879 attempted to ameliorate that, but in fact it should
just be ripped out, which is done here. Also add some regression tests
for json_objectagg in various flavors as a window function.
Original report from Jaime Casanova, diagnosis by Andres Freund.
Discussion: https://postgr.es/m/YkfeMNYRCGhySKyg@ahch-to
src/backend/utils/adt/json.c | 12 ------------
src/test/regress/expected/sqljson.out | 35 +++++++++++++++++++++++++++++++++++
src/test/regress/sql/sqljson.sql | 18 ++++++++++++++++++
3 files changed, 53 insertions(+), 12 deletions(-)
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index 4cf01300d8b..da3f1b97004 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -1002,13 +1002,6 @@ json_unique_builder_init(JsonUniqueBuilderState *cxt)
cxt->skipped_keys.data = NULL;
}
-static void
-json_unique_builder_clean(JsonUniqueBuilderState *cxt)
-{
- if (cxt->skipped_keys.data)
- resetStringInfo(&cxt->skipped_keys);
-}
-
/* On-demand initialization of skipped_keys StringInfo structure */
static StringInfo
json_unique_builder_get_skipped_keys(JsonUniqueBuilderState *cxt)
@@ -1216,8 +1209,6 @@ json_object_agg_finalfn(PG_FUNCTION_ARGS)
if (state == NULL)
PG_RETURN_NULL();
- json_unique_builder_clean(&state->unique_check);
-
/* Else return state with appropriate object terminator added */
PG_RETURN_TEXT_P(catenate_stringinfo_string(state->str, " }"));
}
@@ -1324,9 +1315,6 @@ json_build_object_worker(int nargs, Datum *args, bool *nulls, Oid *types,
appendStringInfoChar(result, '}');
- if (unique_keys)
- json_unique_builder_clean(&unique_check);
-
return PointerGetDatum(cstring_to_text_with_len(result->data, result->len));
}
diff --git a/src/test/regress/expected/sqljson.out b/src/test/regress/expected/sqljson.out
index 6cadd87868a..97a72be970c 100644
--- a/src/test/regress/expected/sqljson.out
+++ b/src/test/regress/expected/sqljson.out
@@ -959,6 +959,41 @@ SELECT JSON_OBJECT('foo' : '1' FORMAT JSON, 'bar' : 'baz' RETURNING json);
CREATE OR REPLACE VIEW public.json_object_view AS
SELECT JSON_OBJECT('foo' : '1'::text FORMAT JSON, 'bar' : 'baz'::text RETURNING json) AS "json_object"
DROP VIEW json_object_view;
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v WITH UNIQUE KEYS) OVER (ORDER BY k)
+FROM (VALUES (1,1), (2,2)) a(k,v);
+ a | json_objectagg
+---------------+----------------------
+ {"k":1,"v":1} | { "1" : 1 }
+ {"k":2,"v":2} | { "1" : 1, "2" : 2 }
+(2 rows)
+
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v WITH UNIQUE KEYS) OVER (ORDER BY k)
+FROM (VALUES (1,1), (1,2), (2,2)) a(k,v);
+ERROR: duplicate JSON key "1"
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v ABSENT ON NULL WITH UNIQUE KEYS)
+ OVER (ORDER BY k)
+FROM (VALUES (1,1), (1,null), (2,2)) a(k,v);
+ERROR: duplicate JSON key "1"
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v ABSENT ON NULL)
+OVER (ORDER BY k)
+FROM (VALUES (1,1), (1,null), (2,2)) a(k,v);
+ a | json_objectagg
+------------------+----------------------
+ {"k":1,"v":1} | { "1" : 1 }
+ {"k":1,"v":null} | { "1" : 1 }
+ {"k":2,"v":2} | { "1" : 1, "2" : 2 }
+(3 rows)
+
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v ABSENT ON NULL)
+OVER (ORDER BY k RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
+FROM (VALUES (1,1), (1,null), (2,2)) a(k,v);
+ a | json_objectagg
+------------------+----------------------
+ {"k":1,"v":1} | { "1" : 1, "2" : 2 }
+ {"k":1,"v":null} | { "1" : 1, "2" : 2 }
+ {"k":2,"v":2} | { "1" : 1, "2" : 2 }
+(3 rows)
+
-- Test JSON_ARRAY deparsing
EXPLAIN (VERBOSE, COSTS OFF)
SELECT JSON_ARRAY('1' FORMAT JSON, 2 RETURNING json);
diff --git a/src/test/regress/sql/sqljson.sql b/src/test/regress/sql/sqljson.sql
index 51fc659b58c..b422ded9780 100644
--- a/src/test/regress/sql/sqljson.sql
+++ b/src/test/regress/sql/sqljson.sql
@@ -292,6 +292,24 @@ SELECT JSON_OBJECT('foo' : '1' FORMAT JSON, 'bar' : 'baz' RETURNING json);
DROP VIEW json_object_view;
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v WITH UNIQUE KEYS) OVER (ORDER BY k)
+FROM (VALUES (1,1), (2,2)) a(k,v);
+
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v WITH UNIQUE KEYS) OVER (ORDER BY k)
+FROM (VALUES (1,1), (1,2), (2,2)) a(k,v);
+
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v ABSENT ON NULL WITH UNIQUE KEYS)
+ OVER (ORDER BY k)
+FROM (VALUES (1,1), (1,null), (2,2)) a(k,v);
+
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v ABSENT ON NULL)
+OVER (ORDER BY k)
+FROM (VALUES (1,1), (1,null), (2,2)) a(k,v);
+
+SELECT to_json(a) AS a, JSON_OBJECTAGG(k : v ABSENT ON NULL)
+OVER (ORDER BY k RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
+FROM (VALUES (1,1), (1,null), (2,2)) a(k,v);
+
-- Test JSON_ARRAY deparsing
EXPLAIN (VERBOSE, COSTS OFF)
SELECT JSON_ARRAY('1' FORMAT JSON, 2 RETURNING json);
[parent: a038679cd876]