Properly detect multiple top level statements

JSON can only have one top level statement. If we get multiple
statements, we should error out appropriately, and we should also avoid
leaking the node for the previously parsed statement.

Fixes: #45

1 files changed, 12 insertions, 15 deletions

diff --git a/json-glib/json-parser.c b/json-glib/json-parser.c
index 3d77975..4e08848 100644
--- a/json-glib/json-parser.c
+++ b/json-glib/json-parser.c
@@ -122,20 +122,9 @@ json_parser_clear (JsonParser *parser)
 {
   JsonParserPrivate *priv = parser->priv;
 
-  g_free (priv->variable_name);
-  priv->variable_name = NULL;
-
-  if (priv->last_error)
-    {
-      g_error_free (priv->last_error);
-      priv->last_error = NULL;
-    }
-
-  if (priv->root)
-    {
-      json_node_unref (priv->root);
-      priv->root = NULL;
-    }
+  g_clear_pointer (&priv->variable_name, g_free);
+  g_clear_pointer (&priv->last_error, g_error_free);
+  g_clear_pointer (&priv->root, json_node_unref);
 }
 
 static void
@@ -880,6 +869,14 @@ json_parse_statement (JsonParser  *parser,
     case G_TOKEN_FLOAT:
     case G_TOKEN_STRING:
     case G_TOKEN_IDENTIFIER:
+      if (priv->root != NULL)
+        {
+          JSON_NOTE (PARSER, "Only one top level statement is possible");
+          json_scanner_get_next_token (scanner);
+          priv->error_code = JSON_PARSER_ERROR_INVALID_BAREWORD;
+          return G_TOKEN_EOF;
+        }
+
       JSON_NOTE (PARSER, "Statement is a value");
       token = json_scanner_get_next_token (scanner);
       return json_parse_value (parser, scanner, token, &priv->root);
@@ -888,7 +885,7 @@ json_parse_statement (JsonParser  *parser,
       JSON_NOTE (PARSER, "Unknown statement");
       json_scanner_get_next_token (scanner);
       priv->error_code = JSON_PARSER_ERROR_INVALID_BAREWORD;
-      return G_TOKEN_SYMBOL;
+      return priv->root != NULL ? G_TOKEN_EOF : G_TOKEN_SYMBOL;
     }
 }