Fix: compute cache_position correctly when inputs_embeds are used dur…
Author: ceyzaguirre4
Pull request: yes

…ing generation with past_key_values

Fix: compute cache_position correctly when inputs_embeds are used during generation with past_key_values

When using inputs_embeds in place of input_ids during incremental generation, the current logic incorrectly initializes cache_position from inputs_embeds alone, which causes incorrect slicing or empty position tensors when past_key_values are present.

This patch initializes cache_position as torch.arange(past_length, past_length + seq_len), ensuring correct rotary embedding alignment.

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