luci-scheduler: Workaround for luci-config reporting ghost configs.

scheduler/appengine/catalog/catalog.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 // Package catalog implements a part that talks to luci-config service to fetch
 // and parse job definitions. Catalog knows about all task types and can
 // instantiate task.Manager's.
 package catalog
 
 import (
@@ skipping 166 matching lines @@
                 if projectName == "" {
                         logging.Warningf(c, "Unexpected ConfigSet: %s", meta.ConfigSet)
                 } else {
                         out = append(out, string(projectName))
                 }
         }
         return out, nil
 }
 
 func (cat *catalog) GetProjectJobs(c context.Context, projectID string) ([]Definition, error) {
+        // TODO(vadimsh): This is a workaround for crbug.com/710619. Remove it once
+        // the bug is fixed.
+        projects, err := cat.GetAllProjects(c)
+        if err != nil {
+                return nil, err
+        }
+        found := false
+        for _, p := range projects {
+                if p == projectID {
+                        found = true
+                }
+        }
+        if !found {
+                return nil, nil
+        }
+
         configSet := cfgtypes.ProjectConfigSet(cfgtypes.ProjectName(projectID))
         configSetURL, err := cfgclient.GetConfigSetURL(c, cfgclient.AsService, configSet)
         switch err {
         case nil: // Continue
         case cfgclient.ErrNoConfig:
                 return nil, nil
         default:
                 return nil, err
         }
 
@@ skipping 219 matching lines @@
                 field := v.Field(i)
                 if field.Type() == taskType {
                         field.Set(reflect.ValueOf(task))
                         return proto.Marshal(&wrapper)
                 }
         }
         // This can happen only if TaskDefWrapper wasn't updated when a new task type
         // was added. This is a developer's mistake, not a config mistake.
         return nil, fmt.Errorf("could not find a field of type %T in TaskDefWrapper", task)
 }