Qwen2_5_VLProcessor.apply_chat_template crashes on batched input when padding=False

[Anakintano]

Bug Description

Qwen2_5_VLProcessor.apply_chat_template raises ValueError: setting an array element with a sequence when processing a batch of ≥2 conversations that include images, under the default padding=False setting.

Root cause: mm_token_type_ids was built by calling np.array(text_inputs["input_ids"]) on a ragged list (variable-length sequences when padding=False). NumPy ≥ 1.24 rejects inhomogeneous shapes for this operation.

This is distinct from #44521, which concerns assistant_masks being all zeros for multimodal inputs.

Reproduction

from transformers import AutoProcessor

processor = AutoProcessor.from_pretrained("Qwen/Qwen2.5-VL-7B-Instruct")

batch_messages = [
    [{"role": "user", "content": [{"type": "image", "image": "img1.jpg"}, {"type": "text", "text": "Describe."}]}],
    [{"role": "user", "content": [{"type": "image", "image": "img2.jpg"}, {"type": "text", "text": "What is this? Give a detailed answer."}]}],
]

processor.apply_chat_template(batch_messages, padding=False, tokenize=True, return_dict=True)
# raises ValueError: setting an array element with a sequence

Expected Behavior

The processor should handle batched inputs without crashing when padding=False.

Fix

A fix is implemented in PR #44535.

[zucchini-nlp]

Duplicate of #44514 and it's not a Qwen problem only. I will fix it for all models, it's much easier than opening a separate PR for each processor

[Anakintano]

Thanks for the clarification! I'll follow the fix in #44514. I'm currently exploring the codebase and learning the contribution workflow.😀