fix(refs): CJK 标签导致 /api/refs/<id>/content 断连 (curl 52)

server.py

@@ -1001,14 +1001,26 @@ def _refs_get_content(self, ref_id: str) -> None:
             self._json({"error": str(e) or "blocked"}, 403)
             return
         etag = forge_refs._compute_etag(data)
+        # Non-ASCII (CJK) header values crash http.server on send; percent-
+        # encode label + source_agent so the response actually reaches the
+        # client. Without this, python's BaseHTTPRequestHandler raises
+        # UnicodeEncodeError writing headers and drops the connection
+        # (curl exit 52 / "Empty reply from server").
+        def _ascii(v: str) -> str:
+            from urllib.parse import quote
+            try:
+                v.encode("latin-1")
+                return v
+            except UnicodeEncodeError:
+                return quote(v, safe="")
         self.send_response(200)
         self.send_header("Content-Type", mime)
         self.send_header("Content-Length", str(len(data)))
         self.send_header("Cache-Control", "no-store")
         self.send_header("ETag", etag)
         self.send_header("X-Ref-Etag", etag)
-        self.send_header("X-Ref-Label", ref.get("label", ""))
-        self.send_header("X-Ref-Source-Agent", ref.get("source_agent", ""))
+        self.send_header("X-Ref-Label", _ascii(ref.get("label", "")))
+        self.send_header("X-Ref-Source-Agent", _ascii(ref.get("source_agent", "")))
         self.send_header("X-Ref-Id", ref.get("id", ""))
         self.end_headers()
         self.wfile.write(data)

tests/test_refs.py

@@ -335,6 +335,25 @@ def test_http_content_round_trip(server, tmp_path):
     assert headers.get("X-Ref-Source-Agent") == "milk"
 
 
+def test_http_content_cjk_label_does_not_crash(server, tmp_path):
+    # Regression: labels with CJK / non-latin-1 chars used to blow up
+    # BaseHTTPRequestHandler when writing X-Ref-Label, killing the
+    # connection (curl exit 52 / "Empty reply from server").
+    from urllib.parse import quote
+    base = server
+    note = tmp_path / "SWAT-\u4f7f\u7528\u6307\u5357.md"
+    note.write_text("# 你好\n", encoding="utf-8")
+    _, body, _ = _call("POST", f"{base}/api/refs", {
+        "label": note.name, "abs_path": str(note), "source_agent": "milk",
+    })
+    rid = body["id"]
+    status, body, headers = _call("GET", f"{base}/api/refs/{rid}/content")
+    assert status == 200
+    assert "你好" in (body if isinstance(body, str) else body.decode("utf-8"))
+    # Header value must be latin-1-safe; ours is percent-encoded.
+    assert headers.get("X-Ref-Label") == quote(note.name, safe="")
+
+
 def test_http_put_content_non_md_400(server, tmp_path):
     # v1: non-md rejected at validation layer -> 400.
     base = server