diff --git a/tools/releasetools/common.py b/tools/releasetools/common.py
index 80f8002..8dcbd0b 100644
--- a/tools/releasetools/common.py
+++ b/tools/releasetools/common.py
@@ -2370,14 +2370,16 @@
   def __init__(self, info_dict, block_diffs, progress_dict=None,
                source_info_dict=None):
     if progress_dict is None:
-      progress_dict = dict()
+      progress_dict = {}
 
     self._remove_all_before_apply = False
     if source_info_dict is None:
       self._remove_all_before_apply = True
-      source_info_dict = dict()
+      source_info_dict = {}
 
-    block_diff_dict = {e.partition:e for e in block_diffs}
+    block_diff_dict = collections.OrderedDict(
+        [(e.partition, e) for e in block_diffs])
+
     assert len(block_diff_dict) == len(block_diffs), \
         "Duplicated BlockDifference object for {}".format(
             [partition for partition, count in
diff --git a/tools/releasetools/test_common.py b/tools/releasetools/test_common.py
index 9b76734..7ce361b 100644
--- a/tools/releasetools/test_common.py
+++ b/tools/releasetools/test_common.py
@@ -1151,7 +1151,7 @@
 class DynamicPartitionsDifferenceTest(test_utils.ReleaseToolsTestCase):
   @staticmethod
   def get_op_list(output_path):
-    with zipfile.ZipFile(output_path, 'r') as output_zip:
+    with zipfile.ZipFile(output_path) as output_zip:
       with output_zip.open("dynamic_partitions_op_list") as op_list:
         return [line.strip() for line in op_list.readlines()
                 if not line.startswith("#")]
@@ -1176,12 +1176,12 @@
 
     self.assertEqual(str(self.script).strip(), """
 assert(update_dynamic_partitions(package_extract_file("dynamic_partitions_op_list")));
-patch(vendor);
-verify(vendor);
-unmap_partition("vendor");
 patch(system);
 verify(system);
 unmap_partition("system");
+patch(vendor);
+verify(vendor);
+unmap_partition("vendor");
 """.strip())
 
     lines = self.get_op_list(self.output_path)
@@ -1229,7 +1229,8 @@
     grown = lines.index("resize_group group_baz 4294967296")
     added = lines.index("add_group group_qux 1073741824")
 
-    self.assertLess(max(removed, shrunk) < min(grown, added),
+    self.assertLess(max(removed, shrunk),
+                    min(grown, added),
                     "ops that remove / shrink partitions must precede ops that "
                     "grow / add partitions")