Fixed noise_pred_text referenced before assignment. (#9537)

* Fixed local variable noise_pred_text referenced before assignment when using PAG with guidance scale and guidance rescale at the same time.

* Fixed style.

* Made returning text pred noise an argument.

src/diffusers/pipelines/pag/pag_utils.py

@@ -98,7 +98,9 @@ class PAGMixin:
         else:
             return self.pag_scale
 
-    def _apply_perturbed_attention_guidance(self, noise_pred, do_classifier_free_guidance, guidance_scale, t):
+    def _apply_perturbed_attention_guidance(
+        self, noise_pred, do_classifier_free_guidance, guidance_scale, t, return_pred_text=False
+    ):
         r"""
         Apply perturbed attention guidance to the noise prediction.
 
@@ -107,9 +109,11 @@ class PAGMixin:
             do_classifier_free_guidance (bool): Whether to apply classifier-free guidance.
             guidance_scale (float): The scale factor for the guidance term.
             t (int): The current time step.
+            return_pred_text (bool): Whether to return the text noise prediction.
 
         Returns:
-            torch.Tensor: The updated noise prediction tensor after applying perturbed attention guidance.
+            Union[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]: The updated noise prediction tensor after applying
+            perturbed attention guidance and the text noise prediction.
         """
         pag_scale = self._get_pag_scale(t)
         if do_classifier_free_guidance:
@@ -122,6 +126,8 @@ class PAGMixin:
         else:
             noise_pred_text, noise_pred_perturb = noise_pred.chunk(2)
             noise_pred = noise_pred_text + pag_scale * (noise_pred_text - noise_pred_perturb)
+        if return_pred_text:
+            return noise_pred, noise_pred_text
         return noise_pred
 
     def _prepare_perturbed_attention_guidance(self, cond, uncond, do_classifier_free_guidance):

src/diffusers/pipelines/pag/pipeline_pag_hunyuandit.py

@@ -893,8 +893,8 @@ class HunyuanDiTPAGPipeline(DiffusionPipeline, PAGMixin):
 
                 # perform guidance
                 if self.do_perturbed_attention_guidance:
-                    noise_pred = self._apply_perturbed_attention_guidance(
-                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t
+                    noise_pred, noise_pred_text = self._apply_perturbed_attention_guidance(
+                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t, True
                     )
                 elif self.do_classifier_free_guidance:
                     noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)

src/diffusers/pipelines/pag/pipeline_pag_sd.py

@@ -993,8 +993,8 @@ class StableDiffusionPAGPipeline(
 
                 # perform guidance
                 if self.do_perturbed_attention_guidance:
-                    noise_pred = self._apply_perturbed_attention_guidance(
-                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t
+                    noise_pred, noise_pred_text = self._apply_perturbed_attention_guidance(
+                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t, True
                     )
 
                 elif self.do_classifier_free_guidance:

src/diffusers/pipelines/pag/pipeline_pag_sd_xl.py

@@ -1237,8 +1237,8 @@ class StableDiffusionXLPAGPipeline(
 
                 # perform guidance
                 if self.do_perturbed_attention_guidance:
-                    noise_pred = self._apply_perturbed_attention_guidance(
-                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t
+                    noise_pred, noise_pred_text = self._apply_perturbed_attention_guidance(
+                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t, True
                     )
 
                 elif self.do_classifier_free_guidance:

src/diffusers/pipelines/pag/pipeline_pag_sd_xl_img2img.py

@@ -1437,8 +1437,8 @@ class StableDiffusionXLPAGImg2ImgPipeline(
 
                 # perform guidance
                 if self.do_perturbed_attention_guidance:
-                    noise_pred = self._apply_perturbed_attention_guidance(
-                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t
+                    noise_pred, noise_pred_text = self._apply_perturbed_attention_guidance(
+                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t, True
                     )
                 elif self.do_classifier_free_guidance:
                     noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)

src/diffusers/pipelines/pag/pipeline_pag_sd_xl_inpaint.py

@@ -1649,8 +1649,8 @@ class StableDiffusionXLPAGInpaintPipeline(
 
                 # perform guidance
                 if self.do_perturbed_attention_guidance:
-                    noise_pred = self._apply_perturbed_attention_guidance(
-                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t
+                    noise_pred, noise_pred_text = self._apply_perturbed_attention_guidance(
+                        noise_pred, self.do_classifier_free_guidance, self.guidance_scale, t, True
                     )
                 elif self.do_classifier_free_guidance:
                     noise_pred_uncond, noise_pred_text = noise_pred.chunk(2)