Skia masters: refuse to merge builds for commits with 'NO_MERGE_BUILDS'

scripts/master/skia/skia_master_utils.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
 """Skia-specific utilities for setting up build masters."""
 
 
 from buildbot.changes import filter as change_filter
 from buildbot.scheduler import AnyBranchScheduler
@@ skipping 35 matching lines @@
 SCHEDULERS = [
   PERCOMMIT_SCHEDULER_NAME,
   MASTER_ONLY_SCHEDULER_NAME,
   TRY_SCHEDULER_NAME,
   PERIODIC_15MINS_SCHEDULER_NAME,
   NIGHTLY_SCHEDULER_NAME,
   WEEKLY_SCHEDULER_NAME,
   INFRA_PERCOMMIT_SCHEDULER_NAME,
 ]
 
+KEYWORD_NO_MERGE_BUILDS = 'NO_MERGE_BUILDS'
+
 
 def CanMergeBuildRequests(req1, req2):
   """Determine whether or not two BuildRequests can be merged.
 
   Rewrite of buildbot.sourcestamp.SourceStamp.canBeMergedWith(), which
   verifies that:
   1. req1.source.repository == req2.source.repository
   2. req1.source.project == req2.source.project
   3. req1.source.branch == req2.source.branch
   4. req1.patch == None and req2.patch = None
@@ skipping 20 matching lines @@
   if (builder_name_schema.IsTrybot(req1.buildername) or
       builder_name_schema.IsTrybot(req2.buildername)):
     return False
 
   # Verify that either: both requests are associated with changes OR neither
   # request is associated with a change but the revisions match (#5 above).
   if req1.source.changes and not req2.source.changes:
     return False
   if not req1.source.changes and req2.source.changes:
     return False
-  if not (req1.source.changes and req2.source.changes):
+  if req1.source.changes and req2.source.changes:
+    for ch in (req1.source.changes + req2.source.changes):
+      if KEYWORD_NO_MERGE_BUILDS in ch.comments:
+        return False
+  else:
     if req1.source.revision != req2.source.revision:
       return False
 
   return True
 
 
 def SetupBuildersAndSchedulers(c, builders, slaves, ActiveMaster):
   """Set up builders and schedulers for the build master."""
   # List of dicts for every builder.
   builder_dicts = []
@@ skipping 245 matching lines @@
         relayhost=config.Master.smtp,
         lookup=master_utils.UsersAreEmails()))
 
     # Rietveld status push.
     if ActiveMaster.code_review_site:
       c['status'].append(
           TryServerHttpStatusPush(serverUrl=ActiveMaster.code_review_site))
 
   c['mergeRequests'] = CanMergeBuildRequests
   return c