Issue 2390: Support appending to $*FLAGS values (CLVar instances) in a

copied construction environment without also affecting the value in
the original construction environment.  (Matt Hughes)

2 files changed, 21 insertions, 11 deletions

diff --git a/src/engine/SCons/EnvironmentTests.py b/src/engine/SCons/EnvironmentTests.py
index ec69607..7feb76d 100644
--- a/src/engine/SCons/EnvironmentTests.py
+++ b/src/engine/SCons/EnvironmentTests.py
@@ -1806,6 +1806,20 @@ def exists(env):
         env2.Append(FLAGS = 'flag3 flag4')
         x = env2.get('FLAGS')
         assert x == ['flag1', 'flag2', 'flag3', 'flag4'], x
+        x = env1.get('FLAGS')
+        assert x == ['flag1', 'flag2'], x
+
+        # Ensure that appending directly to a copied CLVar
+        # doesn't modify the original.
+        env1 = self.TestEnvironment(FLAGS = CLVar('flag1 flag2'))
+        x = env1.get('FLAGS')
+        assert x == ['flag1', 'flag2'], x
+        env2 = env1.Clone()
+        env2['FLAGS'] += ['flag3', 'flag4']
+        x = env2.get('FLAGS')
+        assert x == ['flag1', 'flag2', 'flag3', 'flag4'], x
+        x = env1.get('FLAGS')
+        assert x == ['flag1', 'flag2'], x
 
         # Test that the environment stores the toolpath and
         # re-uses it for copies.
diff --git a/src/engine/SCons/Util.py b/src/engine/SCons/Util.py
index cc6c95e..7a6cb51 100644
--- a/src/engine/SCons/Util.py
+++ b/src/engine/SCons/Util.py
@@ -459,22 +459,18 @@ def _semi_deepcopy_tuple(x):
     return tuple(map(semi_deepcopy, x))
 d[tuple] = _semi_deepcopy_tuple
 
-def _semi_deepcopy_inst(x):
-    if hasattr(x, '__semi_deepcopy__'):
-        return x.__semi_deepcopy__()
-    elif isinstance(x, UserDict):
-        return x.__class__(_semi_deepcopy_dict(x))
-    elif isinstance(x, UserList):
-        return x.__class__(_semi_deepcopy_list(x))
-    else:
-        return x
-d[InstanceType] = _semi_deepcopy_inst
-
 def semi_deepcopy(x):
     copier = _semi_deepcopy_dispatch.get(type(x))
     if copier:
         return copier(x)
     else:
+        if hasattr(x, '__semi_deepcopy__'):
+            return x.__semi_deepcopy__()
+        elif isinstance(x, UserDict):
+            return x.__class__(_semi_deepcopy_dict(x))
+        elif isinstance(x, UserList):
+            return x.__class__(_semi_deepcopy_list(x))
+        
         return x