[json-glib] parser: Detect missing commas in arrays

[Emmanuele Bassi <ebassi src gnome org>]

commit a1490d9b6a3a21774d68f085f805d5f7a68b305e
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Thu Feb 25 09:42:54 2016 +0000

    parser: Detect missing commas in arrays
    
    Just like we detect trailing commas, we should also detect missing ones
    to avoid parsing invalid JSON successfully.

 json-glib/json-parser.c   |   15 ++++++++++++++-
 json-glib/tests/invalid.c |   31 +++++++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 1 deletions(-)
---
diff --git a/json-glib/json-parser.c b/json-glib/json-parser.c
index ee4e765..812f038 100644
--- a/json-glib/json-parser.c
+++ b/json-glib/json-parser.c
@@ -488,12 +488,25 @@ json_parse_array (JsonParser   *parser,
 
       next_token = json_scanner_peek_next_token (scanner);
 
+      /* look for missing commas */
+      if (next_token != G_TOKEN_COMMA && next_token != G_TOKEN_RIGHT_BRACE)
+        {
+          priv->error_code = JSON_PARSER_ERROR_MISSING_COMMA;
+
+          json_array_unref (array);
+          json_node_free (priv->current_node);
+          json_node_free (element);
+          priv->current_node = old_current;
+
+          return G_TOKEN_COMMA;
+        }
+
+      /* look for trailing commas */
       if (next_token == G_TOKEN_COMMA)
         {
           token = json_scanner_get_next_token (scanner);
           next_token = json_scanner_peek_next_token (scanner);
 
-          /* look for trailing commas */
           if (next_token == G_TOKEN_RIGHT_BRACE)
             {
               priv->error_code = JSON_PARSER_ERROR_TRAILING_COMMA;
diff --git a/json-glib/tests/invalid.c b/json-glib/tests/invalid.c
index bac540f..c5fad16 100644
--- a/json-glib/tests/invalid.c
+++ b/json-glib/tests/invalid.c
@@ -143,6 +143,33 @@ test_invalid_object (gconstpointer user_data)
 }
 
 static void
+test_missing_comma (gconstpointer user_data)
+{
+  const char *json = user_data;
+  GError *error = NULL;
+  JsonParser *parser;
+  gboolean res;
+
+  parser = json_parser_new ();
+  g_assert (JSON_IS_PARSER (parser));
+
+  if (g_test_verbose ())
+    g_print ("invalid data: '%s'...", json);
+
+  res = json_parser_load_from_data (parser, json, -1, &error);
+
+  g_assert (!res);
+  g_assert_error (error, JSON_PARSER_ERROR, JSON_PARSER_ERROR_MISSING_COMMA);
+
+  if (g_test_verbose ())
+    g_print ("expected error: %s\n", error->message);
+
+  g_clear_error (&error);
+
+  g_object_unref (parser);
+}
+
+static void
 test_trailing_comma (gconstpointer user_data)
 {
   const char *json = user_data;
@@ -206,6 +233,10 @@ static const struct
   { "object-6", "{ \"a\" : 0 \"b\" : 1 }", test_invalid_object },
   { "object-7", "{ \"\" : false }", test_invalid_object },
 
+  /* missing commas */
+  { "missing-comma-1", "[ true false ]", test_missing_comma },
+  { "missing-comma-2", "{ \"foo\" : 42 \"bar\": null }", test_missing_comma },
+
   /* trailing commas */
   { "trailing-comma-1", "[ true, ]", test_trailing_comma },
   { "trailing-comma-2", "{ \"foo\" : 42, }", test_trailing_comma },