1 files changed, 9 insertions, 2 deletions
diff --git a/tests/wpt/web-platform-tests/common/security-features/tools/generate.py b/tests/wpt/web-platform-tests/common/security-features/tools/generate.py
index 3345d652069..057c4d81ef1 100755
--- a/tests/wpt/web-platform-tests/common/security-features/tools/generate.py
+++ b/tests/wpt/web-platform-tests/common/security-features/tools/generate.py
@@ -3,6 +3,7 @@
 from __future__ import print_function
 
 import argparse
+import collections
 import copy
 import json
 import os
@@ -359,8 +360,14 @@ def main():
         print('Error: No spec.src.json is found at %s.' % spec_directory)
         return
 
-    spec_json = util.load_spec_json(spec_filenames[0])
-    for spec_filename in spec_filenames[1:]:
+    # Load the default spec JSON file, ...
+    default_spec_filename = os.path.join(util.script_directory, 'spec.src.json')
+    spec_json = collections.OrderedDict()
+    if os.path.exists(default_spec_filename):
+        spec_json = util.load_spec_json(default_spec_filename)
+
+    # ... and then make spec JSON files in subdirectories override the default.
+    for spec_filename in spec_filenames:
         child_spec_json = util.load_spec_json(spec_filename)
         merge_json(spec_json, child_spec_json)