patch

diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py
index 8a8cf2776..55120a884 100644
--- a/src/engine/SCons/Action.py
+++ b/src/engine/SCons/Action.py
@@ -502,7 +502,7 @@ def _do_create_list_action(act, kw):
     elif len(acts) == 1:
         return acts[0]
     else:
-        return ListAction(acts)
+        return ListAction(acts, kw)
 
 
 def Action(act, *args, **kw):
@@ -1326,7 +1326,7 @@ class FunctionAction(_ActionAction):
 
 class ListAction(ActionBase):
     """Class for lists of other actions."""
-    def __init__(self, actionlist):
+    def __init__(self, actionlist, batch_key=None, **kw):
         if SCons.Debug.track_instances: logInstanceCreation(self, 'Action.ListAction')
         def list_of_actions(x):
             if isinstance(x, ActionBase):
@@ -1338,6 +1338,19 @@ class ListAction(ActionBase):
         self.varlist = ()
         self.targets = '$TARGETS'
 
+
+        if batch_key:
+            if not callable(batch_key):
+                # They have set batch_key, but not to their own
+                # callable.  The default behavior here will batch
+                # *all* targets+sources using this action, separated
+                # for each construction environment.
+                def default_batch_key(self, env, target, source):
+                    return (id(self), id(env))
+                batch_key = default_batch_key
+            SCons.Util.AddMethod(self, batch_key, 'batch_key')
+
+
     def genstring(self, target, source, env):
         return '\n'.join([a.genstring(target, source, env) for a in self.list])
 

SConstruct_Batch.py

import os

env = Environment(ENV=os.environ)

def action_func(target = None, source = None, env = None):
    print('my targets', target)
    return 0

my_batched_action = env.Action(action_func, batch_key=True)

env.Command(target='hello', source='world', action=my_batched_action)
env.Command(target='goodbye', source='world', action=my_batched_action)

# The above output:
# action_func(["hello", "goodbye"], ["world", "world"])
# ('my targets', [<SCons.Node.FS.File object at 0x55e4f8737250>, <SCons.Node.FS.File object at 0x55e4f87379f0>])

my_second_batched_action = env.Action([action_func, action_func], batch_key=True)

env.Command(target='end', source='world', action=my_second_batched_action)
env.Command(target='sad', source='world', action=my_second_batched_action)

# action_func(["end"], ["world"])
# ('my targets', [<SCons.Node.FS.File object at 0x55e4f8738cb0>])
# action_func(["end"], ["world"])
# ('my targets', [<SCons.Node.FS.File object at 0x55e4f8738cb0>])
# action_func(["sad"], ["world"])
# ('my targets', [<SCons.Node.FS.File object at 0x55e4f8739250>])
# action_func(["sad"], ["world"])
# ('my targets', [<SCons.Node.FS.File object at 0x55e4f8739250>])

# I would expect it to match the first example.