[PixArt-Alpha] fix mask feature condition. (huggingface#5695)

* fix mask feature condition.

* debug

* remove identical test

* set correct

* Empty-Commit

Author: sayakpaul

src/diffusers/pipelines/pixart_alpha/pipeline_pixart_alpha.py

@@ -156,6 +156,8 @@ def encode_prompt(
             mask_feature: (bool, defaults to `True`):
                 If `True`, the function will mask the text embeddings.
         """
+        embeds_initially_provided = prompt_embeds is not None and negative_prompt_embeds is not None
+
         if device is None:
             device = self._execution_device
 
@@ -253,7 +255,7 @@ def encode_prompt(
             negative_prompt_embeds = None
 
         # Perform additional masking.
-        if mask_feature and prompt_embeds is None and negative_prompt_embeds is None:
+        if mask_feature and not embeds_initially_provided:
             prompt_embeds = prompt_embeds.unsqueeze(1)
             masked_prompt_embeds, keep_indices = self.mask_text_embeddings(prompt_embeds, prompt_embeds_attention_mask)
             masked_prompt_embeds = masked_prompt_embeds.squeeze(1)

tests/pipelines/pixart/test_pixart.py

@@ -120,7 +120,6 @@ def test_save_load_optional_components(self):
             "generator": generator,
             "num_inference_steps": num_inference_steps,
             "output_type": output_type,
-            "mask_feature": False,
         }
 
         # set all optional components to None
@@ -155,7 +154,6 @@ def test_save_load_optional_components(self):
             "generator": generator,
             "num_inference_steps": num_inference_steps,
             "output_type": output_type,
-            "mask_feature": False,
         }
 
         output_loaded = pipe_loaded(**inputs)[0]