同步：同步主线

tests/agent/test_truncator.py

@@ -104,8 +104,9 @@ class TestContextTruncator:
             messages, keep_most_recent_turns=0, drop_turns=1
         )
 
-        # Should result in empty or minimal list
-        assert len(result) == 0
+        # 截断后至少保留一条 user 消息 (#6196)
+        assert len(result) >= 1
+        assert result[0].role == "user"
 
     def test_truncate_by_turns_below_threshold(self):
         """Test truncate_by_turns when messages are below threshold."""
@@ -201,8 +202,9 @@ class TestContextTruncator:
         messages = self.create_messages(4)
         result = truncator.truncate_by_dropping_oldest_turns(messages, drop_turns=2)
 
-        # Should drop all turns
-        assert len(result) == 0
+        # 即使 drop 掉所有 turn，也会把 user 消息补回来 (#6196)
+        assert len(result) >= 1
+        assert result[0].role == "user"
 
     def test_truncate_by_dropping_oldest_turns_drop_more_than_available(self):
         """Test truncate_by_dropping_oldest_turns with drop_turns > available turns."""
@@ -211,8 +213,9 @@ class TestContextTruncator:
         messages = self.create_messages(4)
         result = truncator.truncate_by_dropping_oldest_turns(messages, drop_turns=5)
 
-        # Should result in empty list
-        assert len(result) == 0
+        # 同理，user 消息会被保留 (#6196)
+        assert len(result) >= 1
+        assert result[0].role == "user"
 
     def test_truncate_by_dropping_oldest_turns_ensures_user_first(self):
         """Test that result starts with user message after dropping."""
@@ -372,3 +375,60 @@ class TestContextTruncator:
         assert len(result) >= 0  # May keep system messages or clear all
         if len(result) > 0:
             assert all(msg.role == "system" for msg in result)
+
+    # ==================== #6196: 长 tool chain 只有一条 user 消息 ====================
+
+    def _build_tool_chain(self, tool_rounds: int = 20) -> list[Message]:
+        """构造 system -> user -> (assistant -> tool) * N 的长链，只有一条 user。"""
+        msgs = [
+            self.create_message("system", "You are a helpful assistant."),
+            self.create_message("user", "帮我查一下天气"),
+        ]
+        for i in range(tool_rounds):
+            msgs.append(self.create_message("assistant", f"调用工具 {i}"))
+            msgs.append(self.create_message("tool", f"工具结果 {i}"))
+        return msgs
+
+    def test_drop_oldest_preserves_sole_user(self):
+        """#6196: drop 1 turn 不应丢掉唯一的 user 消息。"""
+        truncator = ContextTruncator()
+        msgs = self._build_tool_chain(20)  # 1 system + 1 user + 40 asst/tool = 42
+        result = truncator.truncate_by_dropping_oldest_turns(msgs, drop_turns=1)
+        roles = [m.role for m in result]
+        assert "user" in roles, "唯一的 user 消息被丢掉了"
+        assert roles[0] == "system"
+
+    def test_halving_preserves_sole_user(self):
+        """#6196: 对半砍不应丢掉唯一的 user 消息。"""
+        truncator = ContextTruncator()
+        msgs = self._build_tool_chain(20)
+        result = truncator.truncate_by_halving(msgs)
+        roles = [m.role for m in result]
+        assert "user" in roles, "唯一的 user 消息被丢掉了"
+
+    def test_truncate_by_turns_preserves_sole_user(self):
+        """#6196: keep_most_recent_turns 也不应丢掉唯一的 user 消息。"""
+        truncator = ContextTruncator()
+        msgs = self._build_tool_chain(20)
+        result = truncator.truncate_by_turns(
+            msgs, keep_most_recent_turns=3, drop_turns=1
+        )
+        roles = [m.role for m in result]
+        assert "user" in roles, "唯一的 user 消息被丢掉了"
+
+    def test_drop_oldest_heavy_drops_still_has_user(self):
+        """#6196: 大量 drop 也不会丢 user。"""
+        truncator = ContextTruncator()
+        msgs = self._build_tool_chain(30)
+        result = truncator.truncate_by_dropping_oldest_turns(msgs, drop_turns=10)
+        roles = [m.role for m in result]
+        assert "user" in roles
+
+    def test_normal_multi_user_not_affected(self):
+        """正常多 user 对话不受影响。"""
+        truncator = ContextTruncator()
+        msgs = self.create_messages(20, include_system=True)
+        result_before = truncator.truncate_by_dropping_oldest_turns(msgs, drop_turns=2)
+        # 多 user 场景下截断后仍有 user
+        roles = [m.role for m in result_before]
+        assert "user" in roles

tests/test_anthropic_kimi_code_provider.py

@@ -0,0 +1,81 @@
+import httpx
+
+import astrbot.core.provider.sources.anthropic_source as anthropic_source
+import astrbot.core.provider.sources.kimi_code_source as kimi_code_source
+
+
+class _FakeAsyncAnthropic:
+    def __init__(self, **kwargs):
+        self.kwargs = kwargs
+
+    async def close(self):
+        return None
+
+
+def test_anthropic_provider_injects_custom_headers_into_http_client(monkeypatch):
+    monkeypatch.setattr(anthropic_source, "AsyncAnthropic", _FakeAsyncAnthropic)
+
+    provider = anthropic_source.ProviderAnthropic(
+        provider_config={
+            "id": "anthropic-test",
+            "type": "anthropic_chat_completion",
+            "model": "claude-test",
+            "key": ["test-key"],
+            "custom_headers": {
+                "User-Agent": "custom-agent/1.0",
+                "X-Test-Header": 123,
+            },
+        },
+        provider_settings={},
+    )
+
+    assert provider.custom_headers == {
+        "User-Agent": "custom-agent/1.0",
+        "X-Test-Header": "123",
+    }
+    assert isinstance(provider.client.kwargs["http_client"], httpx.AsyncClient)
+    assert provider.client.kwargs["http_client"].headers["User-Agent"] == "custom-agent/1.0"
+    assert provider.client.kwargs["http_client"].headers["X-Test-Header"] == "123"
+
+
+def test_kimi_code_provider_sets_defaults_and_preserves_custom_headers(monkeypatch):
+    monkeypatch.setattr(anthropic_source, "AsyncAnthropic", _FakeAsyncAnthropic)
+
+    provider = kimi_code_source.ProviderKimiCode(
+        provider_config={
+            "id": "kimi-code",
+            "type": "kimi_code_chat_completion",
+            "key": ["test-key"],
+            "custom_headers": {"X-Trace-Id": "trace-1"},
+        },
+        provider_settings={},
+    )
+
+    assert provider.base_url == kimi_code_source.KIMI_CODE_API_BASE
+    assert provider.get_model() == kimi_code_source.KIMI_CODE_DEFAULT_MODEL
+    assert provider.custom_headers == {
+        "User-Agent": kimi_code_source.KIMI_CODE_USER_AGENT,
+        "X-Trace-Id": "trace-1",
+    }
+    assert provider.client.kwargs["http_client"].headers["User-Agent"] == (
+        kimi_code_source.KIMI_CODE_USER_AGENT
+    )
+    assert provider.client.kwargs["http_client"].headers["X-Trace-Id"] == "trace-1"
+
+
+def test_kimi_code_provider_restores_required_user_agent_when_blank(monkeypatch):
+    monkeypatch.setattr(anthropic_source, "AsyncAnthropic", _FakeAsyncAnthropic)
+
+    provider = kimi_code_source.ProviderKimiCode(
+        provider_config={
+            "id": "kimi-code",
+            "type": "kimi_code_chat_completion",
+            "key": ["test-key"],
+            "custom_headers": {"User-Agent": "   "},
+        },
+        provider_settings={},
+    )
+
+    assert provider.custom_headers == {
+        "User-Agent": kimi_code_source.KIMI_CODE_USER_AGENT,
+    }