Fix file extension for Linux nightly

python/servo/package_commands.py

@@ -628,8 +628,8 @@ def upload_to_s3(platform, package, timestamp):
             nightly_dir = 'nightly/{}'.format(platform)
             filename = nightly_filename(package, timestamp)
             package_upload_key = '{}/{}'.format(nightly_dir, filename)
-            extension = path.splitext(path.basename(package))[1]
-            latest_upload_key = '{}/servo-latest{}'.format(nightly_dir, extension)
+            extension = path.basename(package).partition('.')[2]
+            latest_upload_key = '{}/servo-latest.{}'.format(nightly_dir, extension)
 
             # Compute the hash
             SHA_BUF_SIZE = 1048576  # read in 1 MiB chunks
@@ -642,7 +642,7 @@ def upload_to_s3(platform, package, timestamp):
                     sha256_digest.update(data)
             package_hash = sha256_digest.hexdigest()
             package_hash_fileobj = io.BytesIO(package_hash)
-            latest_hash_upload_key = '{}/servo-latest{}.sha256'.format(nightly_dir, extension)
+            latest_hash_upload_key = '{}/servo-latest.{}.sha256'.format(nightly_dir, extension)
 
             s3.upload_file(package, BUCKET, package_upload_key)