Fix a bug in `AutoPipeline.from_pipe` when switching pipeline with optional components (#6820)

* fix

* add tests

---------
Co-authored-by: yiyixuxu <yixu310@gmail,com>
Co-authored-by: Sayak Paul <spsayakpaul@gmail.com>

src/diffusers/loaders/ip_adapter.py

@@ -166,8 +166,7 @@ class IPAdapterMixin:
                         pretrained_model_name_or_path_or_dict,
                         subfolder=Path(subfolder, "image_encoder").as_posix(),
                     ).to(self.device, dtype=self.dtype)
-                    self.image_encoder = image_encoder
-                    self.register_to_config(image_encoder=["transformers", "CLIPVisionModelWithProjection"])
+                    self.register_modules(image_encoder=image_encoder)
                 else:
                     raise ValueError("`image_encoder` cannot be None when using IP Adapters.")
 

src/diffusers/pipelines/auto_pipeline.py

@@ -13,7 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import inspect
 from collections import OrderedDict
 
 from huggingface_hub.utils import validate_hf_hub_args
@@ -164,14 +163,6 @@ def _get_task_class(mapping, pipeline_class_name, throw_error_if_not_exist: bool
         raise ValueError(f"AutoPipeline can't find a pipeline linked to {pipeline_class_name} for {model_name}")
 
 
-def _get_signature_keys(obj):
-    parameters = inspect.signature(obj.__init__).parameters
-    required_parameters = {k: v for k, v in parameters.items() if v.default == inspect._empty}
-    optional_parameters = set({k for k, v in parameters.items() if v.default != inspect._empty})
-    expected_modules = set(required_parameters.keys()) - {"self"}
-    return expected_modules, optional_parameters
-
-
 class AutoPipelineForText2Image(ConfigMixin):
     r"""
 
@@ -391,7 +382,7 @@ class AutoPipelineForText2Image(ConfigMixin):
                 )
 
         # define expected module and optional kwargs given the pipeline signature
-        expected_modules, optional_kwargs = _get_signature_keys(text_2_image_cls)
+        expected_modules, optional_kwargs = text_2_image_cls._get_signature_keys(text_2_image_cls)
 
         pretrained_model_name_or_path = original_config.pop("_name_or_path", None)
 
@@ -668,7 +659,7 @@ class AutoPipelineForImage2Image(ConfigMixin):
                 )
 
         # define expected module and optional kwargs given the pipeline signature
-        expected_modules, optional_kwargs = _get_signature_keys(image_2_image_cls)
+        expected_modules, optional_kwargs = image_2_image_cls._get_signature_keys(image_2_image_cls)
 
         pretrained_model_name_or_path = original_config.pop("_name_or_path", None)
 
@@ -943,7 +934,7 @@ class AutoPipelineForInpainting(ConfigMixin):
                 )
 
         # define expected module and optional kwargs given the pipeline signature
-        expected_modules, optional_kwargs = _get_signature_keys(inpainting_cls)
+        expected_modules, optional_kwargs = inpainting_cls._get_signature_keys(inpainting_cls)
 
         pretrained_model_name_or_path = original_config.pop("_name_or_path", None)
 

tests/pipelines/test_pipelines_auto.py

@@ -21,6 +21,7 @@ from collections import OrderedDict
 from pathlib import Path
 
 import torch
+from transformers import CLIPVisionConfig, CLIPVisionModelWithProjection
 
 from diffusers import (
     AutoPipelineForImage2Image,
@@ -48,6 +49,20 @@ PRETRAINED_MODEL_REPO_MAPPING = OrderedDict(
 
 
 class AutoPipelineFastTest(unittest.TestCase):
+    @property
+    def dummy_image_encoder(self):
+        torch.manual_seed(0)
+        config = CLIPVisionConfig(
+            hidden_size=1,
+            projection_dim=1,
+            num_hidden_layers=1,
+            num_attention_heads=1,
+            image_size=1,
+            intermediate_size=1,
+            patch_size=1,
+        )
+        return CLIPVisionModelWithProjection(config)
+
     def test_from_pipe_consistent(self):
         pipe = AutoPipelineForText2Image.from_pretrained(
             "hf-internal-testing/tiny-stable-diffusion-pipe", requires_safety_checker=False
@@ -204,6 +219,20 @@ class AutoPipelineFastTest(unittest.TestCase):
         assert pipe_control_img2img.__class__.__name__ == "StableDiffusionControlNetImg2ImgPipeline"
         assert "controlnet" in pipe_control_img2img.components
 
+    def test_from_pipe_optional_components(self):
+        image_encoder = self.dummy_image_encoder
+
+        pipe = AutoPipelineForText2Image.from_pretrained(
+            "hf-internal-testing/tiny-stable-diffusion-pipe",
+            image_encoder=image_encoder,
+        )
+
+        pipe = AutoPipelineForImage2Image.from_pipe(pipe)
+        assert pipe.image_encoder is not None
+
+        pipe = AutoPipelineForText2Image.from_pipe(pipe, image_encoder=None)
+        assert pipe.image_encoder is None
+
 
 @slow
 class AutoPipelineIntegrationTest(unittest.TestCase):