From 28161f13c92aee87dc2401dc5066b10aa95c3cad Mon Sep 17 00:00:00 2001
From: Miaopeng Yu <i23333@icloud.com>
Date: Sun, 12 Jul 2026 13:55:05 +0800
Subject: [PATCH] Fix Gmail multi-label filtering

---
 .../mock-gmail/mock_gmail/api/messages.py     |  4 ++-
 .../environments/mock-gmail/tests/test_api.py | 33 +++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/packages/environments/mock-gmail/mock_gmail/api/messages.py b/packages/environments/mock-gmail/mock_gmail/api/messages.py
index b9204a6df..ebdfcefeb 100644
--- a/packages/environments/mock-gmail/mock_gmail/api/messages.py
+++ b/packages/environments/mock-gmail/mock_gmail/api/messages.py
@@ -253,7 +253,9 @@ def list_messages(
             elif lid == "SENT":
                 query = query.filter(Message.is_sent == True)
             else:
-                query = query.join(MessageLabel).filter(MessageLabel.label_id == lid)
+                query = query.filter(
+                    Message.labels.any(MessageLabel.label_id == lid)
+                )
 
     if q:
         filters = _parse_search_query(q)
diff --git a/packages/environments/mock-gmail/tests/test_api.py b/packages/environments/mock-gmail/tests/test_api.py
index fe869ae98..4b11c881b 100644
--- a/packages/environments/mock-gmail/tests/test_api.py
+++ b/packages/environments/mock-gmail/tests/test_api.py
@@ -37,6 +37,39 @@ def test_list_messages(self, client):
         assert "id" in data["messages"][0]
         assert "threadId" in data["messages"][0]
 
+    def test_list_messages_with_multiple_labels(self, client):
+        first_label_id = client.post(
+            "/gmail/v1/users/me/labels", json={"name": "First filter label"}
+        ).json()["id"]
+        second_label_id = client.post(
+            "/gmail/v1/users/me/labels", json={"name": "Second filter label"}
+        ).json()["id"]
+
+        matching_message = client.post(
+            "/gmail/v1/users/me/messages",
+            json={
+                "raw": _raw(subject="Matches both labels"),
+                "labelIds": [first_label_id, second_label_id],
+            },
+        ).json()
+        client.post(
+            "/gmail/v1/users/me/messages",
+            json={
+                "raw": _raw(subject="Matches only one label"),
+                "labelIds": [first_label_id],
+            },
+        )
+
+        resp = client.get(
+            "/gmail/v1/users/me/messages",
+            params=[("labelIds", first_label_id), ("labelIds", second_label_id)],
+        )
+
+        assert resp.status_code == 200
+        assert [message["id"] for message in resp.json()["messages"]] == [
+            matching_message["id"]
+        ]
+
     def test_get_message(self, client):
         # First list to get an ID
         resp = client.get("/gmail/v1/users/me/messages")