dvc: don't check if stage is changed twice

Signed-off-by: Ruslan Kuprieiev <[email protected]>

dvc/project.py

@@ -125,12 +125,11 @@ class Project(object):
         return stage
 
     def _reproduce_stage(self, stages, node, force):
-        if not stages[node].changed() and not force:
+        stage = stages[node].reproduce(force=force)
+        if not stage:
             return []
-
-        stages[node].reproduce(force=force)
-        stages[node].dump()
-        return [stages[node]]
+        stage.dump()
+        return [stage]
 
     def reproduce(self, target, recursive=True, force=False):
         stages = nx.get_node_attributes(self.graph(), 'stage')

dvc/stage.py

@@ -80,7 +80,7 @@ class Stage(object):
 
     def reproduce(self, force=False):
         if not self.changed() and not force:
-            return
+            return None
 
         if self.cmd:
             # Removing outputs only if we actually have command to reproduce
@@ -88,6 +88,8 @@ class Stage(object):
 
         self.run()
 
+        return self
+
     @staticmethod
     def loadd(project, d, path):
         path = os.path.abspath(path)