From c2d26c918a5bcc3fe7333bc2fe0a07a2d9bc6884 Mon Sep 17 00:00:00 2001
From: Aaron Tan <jangsutsr@gmail.com>
Date: Thu, 27 Apr 2017 16:16:05 -0400
Subject: [PATCH] Allow DRF parser to accept trailing commas.

---
 awx/api/parsers.py                      | 22 +++++++++++++++++++++-
 awx/main/tests/unit/api/test_parsers.py | 15 +++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 awx/main/tests/unit/api/test_parsers.py

diff --git a/awx/api/parsers.py b/awx/api/parsers.py
index 826c67189a..dbb659e7d9 100644
--- a/awx/api/parsers.py
+++ b/awx/api/parsers.py
@@ -12,6 +12,26 @@ from rest_framework import parsers
 from rest_framework.exceptions import ParseError
 
 
+def _remove_trailing_commas(data):
+    left = 0
+    right = 0
+    in_string = False
+    ret = []
+    while left != len(data):
+        if data[left] == ',' and not in_string:
+            while right != len(data) and data[right] in ',\n\t\r ':
+                right += 1
+            if right == len(data) or data[right] not in '}]':
+                ret.append(',')
+        else:
+            if data[left] == '"' and (left - 1 >= 0 and data[left - 1] != '\\'):
+                in_string = not in_string
+            ret.append(data[left])
+            right += 1
+        left = right
+    return ''.join(ret)
+
+
 class JSONParser(parsers.JSONParser):
     """
     Parses JSON-serialized data, preserving order of dictionary keys.
@@ -25,7 +45,7 @@ class JSONParser(parsers.JSONParser):
         encoding = parser_context.get('encoding', settings.DEFAULT_CHARSET)
 
         try:
-            data = stream.read().decode(encoding)
+            data = _remove_trailing_commas(stream.read().decode(encoding))
             obj = json.loads(data, object_pairs_hook=OrderedDict)
             if not isinstance(obj, dict):
                 raise ParseError(_('JSON parse error - not a JSON object'))
diff --git a/awx/main/tests/unit/api/test_parsers.py b/awx/main/tests/unit/api/test_parsers.py
new file mode 100644
index 0000000000..eae4a14913
--- /dev/null
+++ b/awx/main/tests/unit/api/test_parsers.py
@@ -0,0 +1,15 @@
+import pytest
+
+from awx.api.parsers import _remove_trailing_commas
+
+
+@pytest.mark.parametrize('input_, output', [
+    ('{"foo": "bar"}', '{"foo": "bar"}'),
+    ('{"foo": "bar",\n\t\r }', '{"foo": "bar"}'),
+    ('{"foo": ["alice", "bob"]}', '{"foo": ["alice","bob"]}'),
+    ('{"foo": ["alice", "bob",\n\t\r ]}', '{"foo": ["alice","bob"]}'),
+    ('{"foo": "\\"bar,\n\t\r }"}', '{"foo": "\\"bar,\n\t\r }"}'),
+    ('{"foo": ["\\"alice,\n\t\r ]", "bob"]}', '{"foo": ["\\"alice,\n\t\r ]","bob"]}'),
+])
+def test_remove_trailing_commas(input_, output):
+    assert _remove_trailing_commas(input_) == output