Add an error message when a plist turns out not to contain a dict

This is error handling for issue #55 and should hopefully be helpful for understanding the scenario as well.

osxcollector/osxcollector.py

@@ -34,8 +34,8 @@
 from hashlib import sha256
 from json import dumps
 from numbers import Number
-from sqlite3 import connect
 from sqlite3 import OperationalError
+from sqlite3 import connect
 from traceback import extract_tb
 
 import Foundation
@@ -612,7 +612,14 @@ def _read_plist(self, plist_path):
                 plist_path, Foundation.NSUncachedRead, None)
             plist_dictionary, _, _ = Foundation.NSPropertyListSerialization.propertyListFromData_mutabilityOption_format_errorDescription_(
                 plist_nsdata, Foundation.NSPropertyListMutableContainers, None, None)
-            return _normalize_val(plist_dictionary)
+            plist = _normalize_val(plist_dictionary)
+
+            # If the output of _read_plist is not a dict, things aren't going to work properly. Log an informative error.
+            if not isinstance(plist, dict):
+                Logger.log_error('plist is wrong type. plist_path[{0}] type[{1}]'.format(plist_path, plist.__class__.__name__))
+                plist = {}
+
+            return plist
         except Exception as read_plist_e:
             Logger.log_exception(read_plist_e, message='_read_plist failed on {0}'.format(plist_path))
 

tests/output_filters/related_files_test.py

@@ -1,8 +1,8 @@
 # -*- coding: utf-8 -*-
 import testify as T
 from osxcollector.output_filters.related_files import RelatedFilesFilter
-from tests.output_filters.run_filter_test import assert_equal_sorted
 from tests.output_filters.run_filter_test import RunFilterTest
+from tests.output_filters.run_filter_test import assert_equal_sorted
 
 
 def when_anytime(blob):