Fix ControlNetUnit copy issue (#2910)

* Fix ControlNetUnit copy issue

* Add copy test

internal_controlnet/args.py

@@ -471,3 +471,7 @@ class ControlNetUnit(BaseModel):
                 for (key, value) in (item.strip().split(": "),)
             },
         )
+
+    def __copy__(self) -> ControlNetUnit:
+        """Override the behavior on `copy.copy` calls."""
+        return self.copy()

unit_tests/args_test.py

@@ -1,6 +1,7 @@
 import pytest
 import torch
 import numpy as np
+from copy import copy
 from dataclasses import dataclass
 
 from internal_controlnet.args import ControlNetUnit
@@ -249,3 +250,11 @@ def test_infotext_parsing():
 
 def test_alias():
     ControlNetUnit.from_dict({"lowvram": True})
+
+
+def test_copy():
+    unit1 = ControlNetUnit(enabled=True, module="none")
+    unit2 = copy(unit1)
+    unit2.enabled = False
+    assert unit1.enabled
+    assert not unit2.enabled