Set default value newly gitlinks from applied patches.

Bug: 1471685
Change-Id: I850778f030f77bda746227c3e2fde4bbaee55a3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/4775447
Reviewed-by: Josip Sokcevic <sokcevic@chromium.org>
Commit-Queue: Joanna Wang <jojwang@chromium.org>
Auto-Submit: Joanna Wang <jojwang@chromium.org>

gclient.py

@@ -995,9 +995,17 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
         path = module['path']
       else:
         path = f'{self.name}/{module["path"]}'
+      # TODO(crbug.com/1471685): Temporary hack. In case of applied patches
+      # where the changes are staged but not committed, any gitlinks from
+      # the patch are not returned by `git ls-tree`. The path won't be found
+      # in commit_hashes. Use a temporary '0000000' value that will be replaced
+      # with w/e is found in DEPS later.
       submodules[path] = {
-          'dep_type': 'git',
-          'url': '{}@{}'.format(module['url'], commit_hashes[module['path']])
+          'dep_type':
+          'git',
+          'url':
+          '{}@{}'.format(module['url'],
+                         commit_hashes.get(module['path'], '0000000'))
       }
 
       if 'gclient-condition' in module: