chat : Granite Docling stopping (#16438)

* fix: Fix duplicate fake image before token on first slice

Branch: GraniteDoclingStopping

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

* fix: Use double-newline before overview image

Branch: GraniteDoclingStopping

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

* fix: Remove incorrect newline at the end of granite chat template gen prompt

There should not be one, even for the language models.

Branch: GraniteDoclingStopping

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

* tests: Remove bad newline from granite chat template test (legacy)

Branch: GraniteDoclingStopping

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

---------

Signed-off-by: Gabe Goodhart <ghart@us.ibm.com>

src/llama-chat.cpp

@@ -590,7 +590,7 @@ int32_t llm_chat_apply_template(
             ss << message->content << "<|end_of_text|>\n";
         }
         if (add_ass) {
-            ss << "<|start_of_role|>assistant<|end_of_role|>\n";
+            ss << "<|start_of_role|>assistant<|end_of_role|>";
         }
     } else if (tmpl == LLM_CHAT_TEMPLATE_GIGACHAT) {
         // GigaChat template

tests/test-chat-template.cpp

@@ -214,7 +214,7 @@ int main(void) {
         {
             /* .name= */ "ibm-granite/granite-3.0-8b-instruct",
             /* .template_str= */ "{%- if tools %}\n    {{- '<|start_of_role|>available_tools<|end_of_role|>\n' }}\n    {%- for tool in tools %}\n    {{- tool | tojson(indent=4) }}\n    {%- if not loop.last %}\n        {{- '\n\n' }}\n    {%- endif %}\n    {%- endfor %}\n    {{- '<|end_of_text|>\n' }}\n{%- endif %}\n{%- for message in messages %}\n    {%- if message['role'] == 'system' %}\n    {{- '<|start_of_role|>system<|end_of_role|>' + message['content'] + '<|end_of_text|>\n' }}\n    {%- elif message['role'] == 'user' %}\n    {{- '<|start_of_role|>user<|end_of_role|>' + message['content'] + '<|end_of_text|>\n' }}\n    {%- elif message['role'] == 'assistant' %}\n    {{- '<|start_of_role|>assistant<|end_of_role|>'  + message['content'] + '<|end_of_text|>\n' }}\n    {%- elif message['role'] == 'assistant_tool_call' %}\n    {{- '<|start_of_role|>assistant<|end_of_role|><|tool_call|>' + message['content'] + '<|end_of_text|>\n' }}\n    {%- elif message['role'] == 'tool_response' %}\n    {{- '<|start_of_role|>tool_response<|end_of_role|>' + message['content'] + '<|end_of_text|>\n' }}\n    {%- endif %}\n    {%- if loop.last and add_generation_prompt %}\n    {{- '<|start_of_role|>assistant<|end_of_role|>' }}\n    {%- endif %}\n{%- endfor %}",
-            /* .expected_output= */       "<|start_of_role|>system<|end_of_role|>You are a helpful assistant<|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Hello<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>Hi there<|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Who are you<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>   I am an assistant   <|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Another question<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>\n",
+            /* .expected_output= */       "<|start_of_role|>system<|end_of_role|>You are a helpful assistant<|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Hello<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>Hi there<|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Who are you<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>   I am an assistant   <|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Another question<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>",
             /* .expected_output_jinja= */ "<|start_of_role|>system<|end_of_role|>You are a helpful assistant<|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Hello<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>Hi there<|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Who are you<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>   I am an assistant   <|end_of_text|>\n<|start_of_role|>user<|end_of_role|>Another question<|end_of_text|>\n<|start_of_role|>assistant<|end_of_role|>",
         },
         {

tools/mtmd/mtmd.cpp

@@ -249,10 +249,9 @@ struct mtmd_context {
         } else if (proj == PROJECTOR_TYPE_IDEFICS3) {
             // https://github.com/huggingface/transformers/blob/a42ba80fa520c784c8f11a973ca9034e5f859b79/src/transformers/models/idefics3/processing_idefics3.py#L192-L215
             slice_tmpl         = MTMD_SLICE_TMPL_IDEFICS3;
-            tok_ov_img_start   = {lookup_token("\n"), lookup_token("<fake_token_around_image>"), lookup_token("<global-img>")};
+            tok_ov_img_start   = {lookup_token("\n\n"), lookup_token("<fake_token_around_image>"), lookup_token("<global-img>")};
             tok_ov_img_end     = {lookup_token("<fake_token_around_image>")};
             tok_row_end        = {lookup_token("\n")};
-            img_beg            = "<fake_token_around_image>";
             sli_img_start_tmpl = "<fake_token_around_image><row_%d_col_%d>";
 
         } else if (proj == PROJECTOR_TYPE_PIXTRAL) {