gguf-py : add support for chat template jinja files (ggml-org#14508)

* add support for chat template jinja files

* remove gemma3n hack

Author: CISC

convert_hf_to_gguf.py

@@ -4408,9 +4408,6 @@ def __init__(self, *args, **kwargs):
         ]
 
     def set_vocab(self):
-        with open(self.dir_model / "chat_template.jinja") as f:
-            # quick hack to make sure chat template is added
-            self.gguf_writer.add_chat_template(f.read())
         super().set_vocab()
 
     def set_gguf_parameters(self):

gguf-py/gguf/vocab.py

@@ -245,9 +245,18 @@ def _try_load_from_tokenizer_json(self, path: Path) -> bool:
         if not tokenizer_config:
             return True
         chat_template_alt = None
-        chat_template_file = path / 'chat_template.json'
-        if chat_template_file.is_file():
-            with open(chat_template_file, encoding = 'utf-8') as f:
+        chat_template_json = path / 'chat_template.json'
+        chat_template_jinja = path / 'chat_template.jinja'
+        if chat_template_jinja.is_file():
+            with open(chat_template_jinja, encoding = 'utf-8') as f:
+                chat_template_alt = f.read()
+            if additional_templates := list((path / 'additional_chat_templates').glob('*.jinja')):
+                chat_template_alt = [{'name': 'default', 'template': chat_template_alt}]
+                for template_path in additional_templates:
+                    with open(template_path, encoding = 'utf-8') as fp:
+                        chat_template_alt.append({'name': template_path.stem, 'template': fp.read()})
+        elif chat_template_json.is_file():
+            with open(chat_template_json, encoding = 'utf-8') as f:
                 chat_template_alt = json.load(f).get('chat_template')
         chat_template = tokenizer_config.get('chat_template', chat_template_alt)
         if chat_template is None or isinstance(chat_template, (str, list)):