From: Andrew Dunstan <andrew@dunslane.net>
Date: Thu, 25 Sep 2014 12:18:18 +0000 (-0400)
Subject: Return NULL from json_object_agg if it gets no rows.
X-Git-Tag: REL9_4_BETA3~25
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=bda1d14360404ef58c4647888032158991051b14;p=postgresql

Return NULL from json_object_agg if it gets no rows.

This makes it consistent with the docs and with all other builtin
aggregates apart from count().
---

diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
index 494a028526..1820029fe9 100644
--- a/src/backend/utils/adt/json.c
+++ b/src/backend/utils/adt/json.c
@@ -1973,7 +1973,7 @@ json_object_agg_finalfn(PG_FUNCTION_ARGS)
 	state = PG_ARGISNULL(0) ? NULL : (StringInfo) PG_GETARG_POINTER(0);
 
 	if (state == NULL)
-		PG_RETURN_TEXT_P(cstring_to_text("{}"));
+		PG_RETURN_NULL();
 
 	appendStringInfoString(state, " }");