SDXL ControlNet Union pipelines, make control_image argument immutible (#10663)

controlnet union XL, make control_image immutible

when this argument is passed a list, __call__
modifies its content, since it is pass by reference
the list passed by the caller gets its content
modified unexpectedly

make a copy at method intro so this does not happen

Co-authored-by: Teriks <Teriks@users.noreply.github.com>

src/diffusers/pipelines/controlnet/pipeline_controlnet_union_inpaint_sd_xl.py

@@ -1350,6 +1350,8 @@ class StableDiffusionXLControlNetUnionInpaintPipeline(
 
         if not isinstance(control_image, list):
             control_image = [control_image]
+        else:
+            control_image = control_image.copy()
 
         if not isinstance(control_mode, list):
             control_mode = [control_mode]

src/diffusers/pipelines/controlnet/pipeline_controlnet_union_sd_xl.py

@@ -1140,6 +1140,8 @@ class StableDiffusionXLControlNetUnionPipeline(
 
         if not isinstance(control_image, list):
             control_image = [control_image]
+        else:
+            control_image = control_image.copy()
 
         if not isinstance(control_mode, list):
             control_mode = [control_mode]

src/diffusers/pipelines/controlnet/pipeline_controlnet_union_sd_xl_img2img.py

@@ -1286,6 +1286,8 @@ class StableDiffusionXLControlNetUnionImg2ImgPipeline(
 
         if not isinstance(control_image, list):
             control_image = [control_image]
+        else:
+            control_image = control_image.copy()
 
         if not isinstance(control_mode, list):
             control_mode = [control_mode]