From 7d59ec1a3a2fc9a6bb96eeb06afa609e0b5665d7 Mon Sep 17 00:00:00 2001
From: Olof hagsand <olof@hagsand.se>
Date: Wed, 9 Jun 2021 11:44:28 +0200
Subject: [PATCH] * Fixed: [JSON parsing error for a specific input.
 #236](https://github.com/clicon/clixon/issues/236)   * JSON empty list parse
 problems, eg `a:[]`

---
 CHANGELOG.md                |  2 ++
 lib/src/clixon_json_parse.y | 16 +++++-----------
 test/test_json.sh           | 14 +++++++++++---
 test/test_restconf.sh       |  2 +-
 4 files changed, 19 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 59c00e4d..b007ea0e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -97,6 +97,8 @@ Developers may need to change their code
 	
 ### Corrected Bugs
 
+* Fixed: [JSON parsing error for a specific input. #236](https://github.com/clicon/clixon/issues/236)
+  * JSON empty list parse problems, eg `a:[]`
 * Fixed: [restconf patch method unable to chage value to empty string #229](https://github.com/clicon/clixon/issues/229)
 * Fixed: [when condition error under augment in restconf #227](https://github.com/clicon/clixon/issues/227)
 * Fixed: [Using YANG union with decimal64 and string leads to regexp match fail #226](https://github.com/clicon/clixon/issues/226)
diff --git a/lib/src/clixon_json_parse.y b/lib/src/clixon_json_parse.y
index b203d921..d9db980c 100644
--- a/lib/src/clixon_json_parse.y
+++ b/lib/src/clixon_json_parse.y
@@ -209,6 +209,7 @@ json_current_new(clixon_json_yacc *jy,
 static int
 json_current_pop(clixon_json_yacc *jy)
 {
+    clicon_debug(2, "%s", __FUNCTION__);
     if (jy->jy_current) 
 	jy->jy_current = xml_parent(jy->jy_current);
     return 0;
@@ -219,6 +220,7 @@ json_current_clone(clixon_json_yacc *jy)
 {
     cxobj *xn;
 
+    clicon_debug(2, "%s", __FUNCTION__);
     if (jy->jy_current == NULL){
 	return -1;
     }
@@ -246,14 +248,6 @@ json_current_body(clixon_json_yacc *jy,
     return retval;
  }
 
-static int
-json_empty_list(clixon_json_yacc *jy)
-{
-    xml_rm(jy->jy_current);
-    jy->jy_current = NULL;
-    return 0;
-}
-
 %} 
  
 %%
@@ -284,15 +278,15 @@ objlist       : pair             { _PARSE_DEBUG("objlist->pair");}
               ;
 
 pair          : string { json_current_new(_JY, $1);free($1);} ':' 
-                value { json_current_pop(_JY);}{ _PARSE_DEBUG("pair->string : value");}
+                value  { json_current_pop(_JY);}{ _PARSE_DEBUG("pair->string : value");}
               ;
 
-array         : '[' ']'           { json_empty_list(_JY); _PARSE_DEBUG("array->[]"); }
+array         : '[' ']'           { _PARSE_DEBUG("array->[]"); }
               | '[' valuelist ']' { _PARSE_DEBUG("array->[ valuelist ]"); }
               ;
 
 valuelist     : value             { _PARSE_DEBUG("valuelist->value"); }
-              | valuelist { if (json_current_clone(_JY)< 0) _YYERROR("stack?");}
+              | valuelist         { if (json_current_clone(_JY)< 0) _YYERROR("stack?");}
                 ',' value         { _PARSE_DEBUG("valuelist->valuelist , value");}
               ;
 
diff --git a/test/test_json.sh b/test/test_json.sh
index 3cf33ca8..d40b9477 100755
--- a/test/test_json.sh
+++ b/test/test_json.sh
@@ -64,8 +64,7 @@ expecteofx "$clixon_util_json" 0 '{"a":[0,1,2,3]}' "<a>0</a><a>1</a><a>2</a><a>3
 
 # See test_restconf.sh
 new "json parse empty list to xml"
-expecteofx "$clixon_util_json" 0 '{"a":[]}' "
-" # XXX empty
+expecteofx "$clixon_util_json" 0 '{"a":[]}' "<a/>"
 
 new "json parse list json" # should be {"a":[0,1,2,3]}
 expecteofx "$clixon_util_json -j" 0 '{"a":[0,1,2,3]}' '{"a":"0"}{"a":"1"}{"a":"2"}{"a":"3"}'
@@ -126,7 +125,16 @@ expecteofx "$clixon_util_json -jy $fyang" 0 "$JSON" '{"json:g2":"blues"}'
 new "xml indirect identity with explicit ns to json"
 expecteofx "$clixon_util_xml -ojvy $fyang" 0 '<g2 xmlns="urn:example:clixon" xmlns:ex="urn:example:clixon">ex:blues</g2>' '{"json:g2":"blues"}'
 
-# XXX CDATA translation, should work bit does not
+# See https://github.com/clicon/clixon/issues/236
+JSON='{"data": {"a": [],"b": [{"name": 17},{"name": 42},{"name": 99}]}}'
+new "empty list followed by list"
+expecteofx "$clixon_util_json" 0 "$JSON" "<data><a/><b><name>17</name></b><b><name>42</name></b><b><name>99</name></b></data>"
+
+JSON='{"data": {"a": [],"b": [{"name": 17},{"name": []},{"name": 99}]}}'
+new "empty list followed by list again empty"
+expecteofx "$clixon_util_json" 0 "$JSON" "<data><a/><b><name>17</name></b><b><name/></b><b><name>99</name></b></data>"
+
+# XXX CDATA translation, should work but does not
 if false; then
 JSON='{"json:c": {"s": "<![CDATA[  z > x  & x < y ]]>"}}'
 new "json parse cdata xml"
diff --git a/test/test_restconf.sh b/test/test_restconf.sh
index 90f31067..6ba4b22d 100755
--- a/test/test_restconf.sh
+++ b/test/test_restconf.sh
@@ -314,7 +314,7 @@ function testrun()
 
 # See test_json.sh
     new "restconf empty list"
-    expectpart "$(curl $CURLOPTS -X POST -H "Accept: application/yang-data+json" -H "Content-Type: application/yang-data+json" -d '{"clixon-example:table":{"parameter":[]}}' $proto://$addr/restconf/data)" 0 "HTTP/$HVER 201" "Location: $proto://$addr/restconf/data/clixon-example:table"
+    expectpart "$(curl $CURLOPTS -X POST -H "Accept: application/yang-data+json" -H "Content-Type: application/yang-data+json" -d '{"clixon-example:table":[]}' $proto://$addr/restconf/data)" 0 "HTTP/$HVER 201" "Location: $proto://$addr/restconf/data/clixon-example:table"
 
     new "restconf Re-add subtree eth/0/0 which should give error"
     expectpart "$(curl $CURLOPTS -X POST -H "Content-Type: application/yang-data+json" -d '{"ietf-interfaces:interfaces":{"interface":{"name":"eth/0/0","type":"clixon-example:eth","enabled":true}}}' $proto://$addr/restconf/data)" 0 '{"ietf-restconf:errors":{"error":{"error-type":"application","error-tag":"data-exists","error-severity":"error","error-message":"Data already exists; cannot create new resource"}}}'