After `become()`, colors of the two VMobjects are linked

[regnarg]

Description of bug / unexpected behavior

After calling a.become(b), where a and b are both VMobjects, their colors become linked. Changing color of a (e.g. with set_stroke also changes color of b and vice versa.

Expected behavior

After become() call, the two Mobjects should be independent and should change colors independently.

How to reproduce the issue

Code for reproducing the problem

from manim import *

class PromoScene(Scene):
    def construct(self):
        a = Circle()
        b = Square()
        self.add(a)
        self.add(b)
        b.become(a)
        b.shift(1*RIGHT)
        b.set_stroke(YELLOW, opacity=1)
        self.wait(1)

Additional media files

Images/GIFs

Result I get:

Expected:

[regnarg]

This seems to fix the issue:

diff '--color=auto' -rubp manim.orig/mobject/types/vectorized_mobject.py manim/mobject/types/vectorized_mobject.py
--- manim.orig/mobject/types/vectorized_mobject.py	2023-12-07 18:55:34.234530207 +0100
+++ manim/mobject/types/vectorized_mobject.py	2023-12-07 18:55:39.241205514 +0100
@@ -1692,7 +1692,7 @@ class VMobject(Mobject):
                 interpolate(getattr(mobject1, attr), getattr(mobject2, attr), alpha),
             )
             if alpha == 1.0:
-                setattr(self, attr, getattr(mobject2, attr))
+                setattr(self, attr, copy.deepcopy(getattr(mobject2, attr)))
 
     def pointwise_become_partial(
         self,