Update comment for Pad prompt/negative prompt v0 to add a warning about...

Update comment for Pad prompt/negative prompt v0 to add a warning about truncation, make it override the v1 implementation

modules/sd_samplers_cfg_denoiser.py

@@ -220,10 +220,10 @@ class CFGDenoiser(torch.nn.Module):
 
         self.padded_cond_uncond = False
         self.padded_cond_uncond_v0 = False
-        if shared.opts.pad_cond_uncond and tensor.shape[1] != uncond.shape[1]:
-            tensor, uncond = self.pad_cond_uncond(tensor, uncond)
-        elif shared.opts.pad_cond_uncond_v0 and tensor.shape[1] != uncond.shape[1]:
+        if shared.opts.pad_cond_uncond_v0 and tensor.shape[1] != uncond.shape[1]:
             tensor, uncond = self.pad_cond_uncond_v0(tensor, uncond)
+        elif shared.opts.pad_cond_uncond and tensor.shape[1] != uncond.shape[1]:
+            tensor, uncond = self.pad_cond_uncond(tensor, uncond)
 
         if tensor.shape[1] == uncond.shape[1] or skip_uncond:
             if is_edit_model:

modules/shared_options.py

@@ -211,7 +211,7 @@ options_templates.update(options_section(('optimizations', "Optimizations", "sd"
     "token_merging_ratio_img2img": OptionInfo(0.0, "Token merging ratio for img2img", gr.Slider, {"minimum": 0.0, "maximum": 0.9, "step": 0.1}).info("only applies if non-zero and overrides above"),
     "token_merging_ratio_hr": OptionInfo(0.0, "Token merging ratio for high-res pass", gr.Slider, {"minimum": 0.0, "maximum": 0.9, "step": 0.1}, infotext='Token merging ratio hr').info("only applies if non-zero and overrides above"),
     "pad_cond_uncond": OptionInfo(False, "Pad prompt/negative prompt", infotext='Pad conds').info("improves performance when prompt and negative prompt have different lengths; changes seeds"),
-    "pad_cond_uncond_v0": OptionInfo(False, "Pad prompt/negative prompt (v0)", infotext='Pad conds v0').info("alternative implementation for the above; used prior to 1.6.0 for DDIM sampler; ignored if the above is set; changes seeds"),
+    "pad_cond_uncond_v0": OptionInfo(False, "Pad prompt/negative prompt (v0)", infotext='Pad conds v0').info("alternative implementation for the above; used prior to 1.6.0 for DDIM sampler; overrides the above if set; WARNING: truncates negative prompt if it's too long; changes seeds"),
     "persistent_cond_cache": OptionInfo(True, "Persistent cond cache").info("do not recalculate conds from prompts if prompts have not changed since previous calculation"),
     "batch_cond_uncond": OptionInfo(True, "Batch cond/uncond").info("do both conditional and unconditional denoising in one batch; uses a bit more VRAM during sampling, but improves speed; previously this was controlled by --always-batch-cond-uncond comandline argument"),
     "fp8_storage": OptionInfo("Disable", "FP8 weight", gr.Radio, {"choices": ["Disable", "Enable for SDXL", "Enable"]}).info("Use FP8 to store Linear/Conv layers' weight. Require pytorch>=2.1.0."),