From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 29 May 2017 22:51:56 +0000 (-0400)
Subject: Fix thinko in JsObjectSize() macro.
X-Git-Tag: REL_10_BETA2~269
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=e45c5be99d08d7bb6708d7bb1dd0f5d99798c6aa;p=postgresql.git

Fix thinko in JsObjectSize() macro.

The macro gave the wrong answers for a JsObject with is_json == 0:
it would return 1 if jsonb_cont == NULL, or if that wasn't NULL,
it would return 1 for any non-zero size.

We could fix that, but the only use of this macro at present is in the
JsObjectIsEmpty() macro, so it seems simpler and clearer to get rid of
JsObjectSize() and put corrected logic into JsObjectIsEmpty().

Thinko in commit cf35346e8, so no need for back-patch.

Nikita Glukhov

Discussion: https://postgr.es/m/fbd1d566-bba0-a3de-d6d0-d3b1d7c24ff2@postgrespro.ru
---

diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
index ab9a7452340..bfd6cd9cbc5 100644
--- a/src/backend/utils/adt/jsonfuncs.c
+++ b/src/backend/utils/adt/jsonfuncs.c
@@ -308,14 +308,14 @@ typedef struct JsObject
 	((jsv)->is_json ? (jsv)->val.json.type == JSON_TOKEN_STRING \
 		: ((jsv)->val.jsonb && (jsv)->val.jsonb->type == jbvString))
 
-#define JsObjectSize(jso) \
+#define JsObjectIsEmpty(jso) \
 	((jso)->is_json \
-		? hash_get_num_entries((jso)->val.json_hash) \
-		: !(jso)->val.jsonb_cont || JsonContainerSize((jso)->val.jsonb_cont))
+		? hash_get_num_entries((jso)->val.json_hash) == 0 \
+		: ((jso)->val.jsonb_cont == NULL || \
+		   JsonContainerSize((jso)->val.jsonb_cont) == 0))
 
-#define JsObjectIsEmpty(jso) (JsObjectSize(jso) == 0)
-
-#define JsObjectFree(jso) do { \
+#define JsObjectFree(jso) \
+	do { \
 		if ((jso)->is_json) \
 			hash_destroy((jso)->val.json_hash); \
 	} while (0)