Model: Add fallback if negative prompt is empty

Fallback to the BOS token since an empty string won't do anything. Ideally, an empty negative prompt should not be used, but it's not the end of the world. Signed-off-by: kingbri <[email protected]>
theroyallab · Jan 2, 2024 · bbd4ee5 · bbd4ee5
1 parent b378773
commit bbd4ee5
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/model.py b/model.py
@@ -585,7 +585,11 @@ def generate_gen(self, prompt: str, **kwargs):
         if cfg_scale not in [None, 1.0]:
             if self.use_cfg:
                 gen_settings.cfg_scale = cfg_scale
-                negative_prompt = kwargs.get("negative_prompt")
+
+                # If the negative prompt is empty, use the BOS token
+                negative_prompt = unwrap(
+                    kwargs.get("negative_prompt"), self.tokenizer.bos_token
+                )
             else:
                 logger.warn(
                     "CFG is currently disabled. "