From 1a1117c7359d1c9fc687fefdd56455f94f7fee10 Mon Sep 17 00:00:00 2001
From: Julien Thomas <jthomas@zenetys.com>
Date: Wed, 23 Sep 2020 20:33:55 +0200
Subject: [PATCH 63/73] Do not create empty objects when accessing non-existent
 keys

This is a proposal for Github issue rsyslog/rsyslog#4430:
accessing a non-existing key creates an empty parent object
https://github.com/rsyslog/rsyslog/issues/4430

When looking up an object property, the tree of intermediate
object containers was ceated by get and del functions. The
patch is an attempt to fix that behavior by passing 0 to the
bCreate argument of jsonPathFindParent().

There is also one case where the return value of
jsonPathFindParent() was not checked, in the recurssive call
of jsonPathFindParent() itself. This was leading to infinite
loops if bCreate was 0.
---
 runtime/msg.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/runtime/msg.c b/runtime/msg.c
index 3acc4f212..b28cf84c5 100644
--- a/runtime/msg.c
+++ b/runtime/msg.c
@@ -3142,7 +3142,7 @@ getJSONPropVal(smsg_t * const pMsg, msgPropDescr_t *pProp, uchar **pRes, rs_size
 		field = *jroot;
 	} else {
 		leaf = jsonPathGetLeaf(pProp->name, pProp->nameLen);
-		CHKiRet(jsonPathFindParent(*jroot, pProp->name, leaf, &parent, 1));
+		CHKiRet(jsonPathFindParent(*jroot, pProp->name, leaf, &parent, 0));
 		if(jsonVarExtract(parent, (char*)leaf, &field) == FALSE)
 			field = NULL;
 	}
@@ -3197,7 +3197,7 @@ msgGetJSONPropJSONorString(smsg_t * const pMsg, msgPropDescr_t *pProp, struct js
 		ABORT_FINALIZE(RS_RET_NOT_FOUND);
 	}
 	leaf = jsonPathGetLeaf(pProp->name, pProp->nameLen);
-	CHKiRet(jsonPathFindParent(*jroot, pProp->name, leaf, &parent, 1));
+	CHKiRet(jsonPathFindParent(*jroot, pProp->name, leaf, &parent, 0));
 	if(jsonVarExtract(parent, (char*)leaf, pjson) == FALSE) {
 		ABORT_FINALIZE(RS_RET_NOT_FOUND);
 	}
@@ -3242,7 +3242,7 @@ msgGetJSONPropJSON(smsg_t * const pMsg, msgPropDescr_t *pProp, struct json_objec
 		FINALIZE;
 	}
 	leaf = jsonPathGetLeaf(pProp->name, pProp->nameLen);
-	CHKiRet(jsonPathFindParent(*jroot, pProp->name, leaf, &parent, 1));
+	CHKiRet(jsonPathFindParent(*jroot, pProp->name, leaf, &parent, 0));
 	if(jsonVarExtract(parent, (char*)leaf, pjson) == FALSE) {
 		ABORT_FINALIZE(RS_RET_NOT_FOUND);
 	}
@@ -4845,7 +4845,7 @@ jsonPathFindParent(struct json_object *jroot, uchar *name, uchar *leaf, struct j
 	namestart = name;
 	*parent = jroot;
 	while(name < leaf-1) {
-		jsonPathFindNext(*parent, namestart, &name, leaf, parent, bCreate);
+		CHKiRet(jsonPathFindNext(*parent, namestart, &name, leaf, parent, bCreate));
 	}
 	if(*parent == NULL)
 		ABORT_FINALIZE(RS_RET_NOT_FOUND);
@@ -5006,7 +5006,7 @@ msgDelJSON(smsg_t * const pM, uchar *name)
 		*jroot = NULL;
 	} else {
 		leaf = jsonPathGetLeaf(name, ustrlen(name));
-		CHKiRet(jsonPathFindParent(*jroot, name, leaf, &parent, 1));
+		CHKiRet(jsonPathFindParent(*jroot, name, leaf, &parent, 0));
 		if(jsonVarExtract(parent, (char*)leaf, &leafnode) == FALSE)
 			leafnode = NULL;
 		if(leafnode == NULL) {
-- 
2.23.0