Roll recipe dependencies (trivial).

This is an automated CL created by the recipe roller. This CL rolls recipe
changes from upstream projects (e.g. depot_tools) into downstream projects
(e.g. tools/build).


More info is at https://goo.gl/zkKdpD. Use https://goo.gl/noib3a to file a bug.
recipe_engine:
  https://crrev.com/c8d78bf15c065b5a35ccfc5798d1498d0899bb68 [doc] Automatically generate and update cross-indexed recipe markdown files. (iannucci@chromium.org)


TBR=iannucci@chromium.org

Recipe-Tryjob-Bypass-Reason: Autoroller
Bugdroid-Send-Email: False
Change-Id: I64f3ebdbf1565f7f8c08c6e21df516f87533ac7b
Reviewed-on: https://chromium-review.googlesource.com/558392Reviewed-by: Recipe Roller <recipe-roller@chromium.org>
Commit-Queue: Recipe Roller <recipe-roller@chromium.org>

infra/config/recipes.cfg

@@ -15,7 +15,7 @@
   "deps": {
     "recipe_engine": {
       "branch": "master",
-      "revision": "5873ef21cc9f2a9d9d6de868608c51976fdca20a",
+      "revision": "c8d78bf15c065b5a35ccfc5798d1498d0899bb68",
       "url": "https://chromium.googlesource.com/external/github.com/luci/recipes-py.git"
     }
   },

recipes/recipes.py

@@ -59,7 +59,8 @@ def parse(repo_root, recipes_cfg_path):
     recipes_cfg_path (str) - native path to the recipes.cfg file to process.
 
   Returns (as tuple):
-    engine_dep (EngineDep): The recipe_engine dependency.
+    engine_dep (EngineDep|None): The recipe_engine dependency, or None, if the
+      current repo IS the recipe_engine.
     recipes_path (str) - native path to where the recipes live inside of the
       current repo (i.e. the folder containing `recipes/` and/or
       `recipe_modules`)
@@ -72,6 +73,11 @@ def parse(repo_root, recipes_cfg_path):
       raise MalformedRecipesCfg('unknown version %d' % pb['api_version'],
                                 recipes_cfg_path)
 
+    # If we're running ./doc/recipes.py from the recipe_engine repo itself, then
+    # return None to signal that there's no EngineDep.
+    if pb['project_id'] == 'recipe_engine':
+      return None, pb.get('recipes_path', '')
+
     engine = pb['deps']['recipe_engine']
 
     if 'url' not in engine:
@@ -141,6 +147,9 @@ def parse_args(argv):
 
 def checkout_engine(engine_path, repo_root, recipes_cfg_path):
   dep, recipes_path = parse(repo_root, recipes_cfg_path)
+  if dep is None:
+    # we're running from the engine repo already!
+    return os.path.join(repo_root, recipes_path)
 
   url = dep.url