[Bugfix][OpenAI] Fix streamed completion logprob offsets with echo (#47815)

Signed-off-by: Ting Sun <suntcrick@gmail.com>

Ting SUN committed Aug 27, 2026 at 18:19 UTC 50708f95aec011d81aeae3258d6532972d2b5ad3
1 file changed +1 -1
vllm/entrypoints/openai/completion/serving.py
+1 -1
@@ -395,7 +395,7 @@ class OpenAIServingCompletion(GenerateBaseServing):
395 else:
396 logprobs = None
397
398 - previous_text_lens[i] += len(output.text)
398 + previous_text_lens[i] += len(delta_text)
399 previous_num_tokens[i] += len(output.token_ids)
400 finish_reason = output.finish_reason
401 stop_reason = output.stop_reason