2 files changed, 26 insertions, 4 deletions
diff --git a/src/engine/SCons/Script/SConscript.py b/src/engine/SCons/Script/SConscript.py
index e30a979..2e8c916 100644
--- a/src/engine/SCons/Script/SConscript.py
+++ b/src/engine/SCons/Script/SConscript.py
@@ -522,11 +522,15 @@ class DefaultEnvironmentCall:
     thereby prevent expansion of construction variables (since from
     the user's point of view this was called as a global function,
     with no associated construction environment)."""
-    def __init__(self, method_name):
+    def __init__(self, method_name, subst=0):
         self.method_name = method_name
+        if subst:
+            self.factory = SCons.Defaults.DefaultEnvironment
+        else:
+            self.factory = get_DefaultEnvironmentProxy
     def __call__(self, *args, **kw):
-        proxy = get_DefaultEnvironmentProxy()
-        method = getattr(proxy, self.method_name)
+        env = self.factory()
+        method = getattr(env, self.method_name)
         return apply(method, args, kw)
 
 
diff --git a/src/engine/SCons/Script/__init__.py b/src/engine/SCons/Script/__init__.py
index d6d4912..d94fee2 100644
--- a/src/engine/SCons/Script/__init__.py
+++ b/src/engine/SCons/Script/__init__.py
@@ -191,7 +191,7 @@ GlobalDefaultEnvironmentFunctions = [
     'BuildDir',
     'CacheDir',
     'Clean',
-    'Command',
+    #The Command() method is handled separately, below.
     'Depends',
     'Dir',
     'Execute',
@@ -245,3 +245,21 @@ GlobalDefaultBuilders = [
 
 for name in GlobalDefaultEnvironmentFunctions + GlobalDefaultBuilders:
     exec "%s = _SConscript.DefaultEnvironmentCall(%s)" % (name, repr(name))
+
+# The global Command() function must be handled differently than the
+# global functions for other construction environment methods because
+# we want people to be able to use Actions that must expand $TARGET
+# and $SOURCE later, when (and if) the Action is invoked to build
+# the target(s).  We do this with the subst=1 argument, which creates
+# a DefaultEnvironmentCall instance that wraps up a normal default
+# construction environment that performs variable substitution, not a
+# proxy that doesn't.
+#
+# There's a flaw here, though, because any other $-variables on a command
+# line will *also* be expanded, each to a null string, but that should
+# only be a problem in the unusual case where someone was passing a '$'
+# on a command line and *expected* the $ to get through to the shell
+# because they were calling Command() and not env.Command()...  This is
+# unlikely enough that we're going to leave this as is and cross that
+# bridge if someone actually comes to it.
+Command = _SConscript.DefaultEnvironmentCall('Command', subst=1)