fix: empty_content false-positive on reasoning models — deepseek-v4-flash/pro return content in reasoning_content; only treat as empty when no content AND no reasoning AND not finish_reason=length

gateway/scripts/ocg_router.py

@@ -612,10 +612,21 @@ class RouterHandler(BaseHTTPRequestHandler):
                     try:
                         import json as _json
                         d = _json.loads(resp_body.decode("utf-8", errors="replace"))
-                        content = d.get("choices", [{}])[0].get("message", {}).get("content", "")
-                        if not content or not str(content).strip():
-                            log.warning("empty content detected via key, retrying next key")
-                            return {"ok": False, "status": 0, "error": "empty_content"}
+                        msg = d.get("choices", [{}])[0].get("message", {}) or {}
+                        content = msg.get("content", "")
+                        # 推理模型（deepseek-v4-flash/pro 等）回复在 reasoning_content，
+                        # content 可能为空（尤其 max_tokens 小时 token 全用于推理）——
+                        # 有 reasoning_content 或 finish_reason=length 都视为正常，不算空输出
+                        reasoning = msg.get("reasoning_content", "")
+                        finish_reason = d.get("choices", [{}])[0].get("finish_reason", "")
+                        has_reasoning = bool(reasoning and str(reasoning).strip())
+                        if (not content or not str(content).strip()) and not has_reasoning:
+                            if finish_reason == "length":
+                                # max_tokens 截断，content 可能为空但属于正常响应
+                                log.warning("content empty but finish_reason=length (truncated), passing through")
+                            else:
+                                log.warning("empty content detected via key, retrying next key")
+                                return {"ok": False, "status": 0, "error": "empty_content"}
                     except Exception:
                         pass  # 解析失败不阻断（正常透传）
                 self._send_response(status, dict(resp.headers), resp_body)