From f46c1df2b1cdf1b0fc18d51d0937acf5a995d28d Mon Sep 17 00:00:00 2001
From: Gaurav Sharma <223556219+Copilot@users.noreply.github.com>
Date: Mon, 29 Jun 2026 13:28:27 +0530
Subject: [PATCH] FIX: forward connection timeout to bulkcopy pycore connection

cursor.bulkcopy() opens a separate connection through mssql-py-core, which defaulted to a hardcoded 15s connect timeout with no way to override it. forward the cursor's query timeout (connect(timeout=X)) into pycore's connect_timeout when set, so the same limit applies to the bulk copy connection. 0 stays a no-override, leaving pycore on its default.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
---
 mssql_python/cursor.py                  |  9 ++++
 tests/test_020_bulkcopy_auth_cleanup.py | 65 +++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/mssql_python/cursor.py b/mssql_python/cursor.py
index aa0eed00a..e43f1b947 100644
--- a/mssql_python/cursor.py
+++ b/mssql_python/cursor.py
@@ -2941,6 +2941,15 @@ def bulkcopy(
         # Translate parsed connection string into the dict py-core expects.
         pycore_context = connstr_to_pycore_params(params)
 
+        # Forward the cursor's query timeout to py-core so the bulkcopy
+        # connection uses the same limit instead of py-core's compiled-in 15s
+        # default. _timeout is the snapshot taken at cursor creation (same value
+        # _set_timeout uses); 0 means "no override", so py-core keeps its default.
+        # type-is-int guard keeps bool/mocked values from leaking through.
+        connect_timeout = self._timeout
+        if type(connect_timeout) is int and connect_timeout > 0:
+            pycore_context["connect_timeout"] = connect_timeout
+
         # Token acquisition — only thing cursor must handle (needs azure-identity SDK)
         if self.connection._auth_type:
             # Fresh token acquisition for mssql-py-core connection
diff --git a/tests/test_020_bulkcopy_auth_cleanup.py b/tests/test_020_bulkcopy_auth_cleanup.py
index 164438344..8ab4cd18a 100644
--- a/tests/test_020_bulkcopy_auth_cleanup.py
+++ b/tests/test_020_bulkcopy_auth_cleanup.py
@@ -26,6 +26,7 @@ def _make_cursor(connection_str, auth_type):
 
     cursor = Cursor.__new__(Cursor)
     cursor._connection = mock_conn
+    cursor._timeout = 0
     cursor.closed = False
     cursor.hstmt = None
     return cursor
@@ -108,3 +109,67 @@ def capture_context(ctx, **kwargs):
         assert "access_token" not in captured_context
         assert captured_context.get("user_name") == "sa"
         assert captured_context.get("password") == "mypwd"
+
+
+def _capture_bulkcopy_context(cursor):
+    """Run bulkcopy with a mocked pycore module and return the captured context."""
+    captured_context = {}
+
+    mock_pycore_cursor = MagicMock()
+    mock_pycore_cursor.bulkcopy.return_value = {
+        "rows_copied": 1,
+        "batch_count": 1,
+        "elapsed_time": 0.1,
+    }
+    mock_pycore_conn = MagicMock()
+    mock_pycore_conn.cursor.return_value = mock_pycore_cursor
+
+    def capture_context(ctx, **kwargs):
+        captured_context.update(ctx)
+        return mock_pycore_conn
+
+    mock_pycore_module = MagicMock()
+    mock_pycore_module.PyCoreConnection = capture_context
+
+    with patch.dict("sys.modules", {"mssql_py_core": mock_pycore_module}):
+        cursor.bulkcopy("dbo.test_table", [(1, "row")], timeout=10)
+
+    return captured_context
+
+
+class TestBulkcopyConnectTimeout:
+    """Verify cursor.bulkcopy forwards the cursor timeout to pycore (issue #626)."""
+
+    @patch("mssql_python.cursor.logger")
+    def test_positive_timeout_forwarded(self, mock_logger):
+        """cursor._timeout > 0 ⇒ connect_timeout reaches pycore, overriding 15s."""
+        mock_logger.is_debug_enabled = False
+        cursor = _make_cursor("Server=localhost;Database=testdb;UID=sa;PWD=pwd", None)
+        cursor._timeout = 30
+
+        captured = _capture_bulkcopy_context(cursor)
+
+        assert captured.get("connect_timeout") == 30
+
+    @patch("mssql_python.cursor.logger")
+    def test_zero_timeout_not_forwarded(self, mock_logger):
+        """cursor._timeout == 0 ⇒ no override, pycore keeps its default."""
+        mock_logger.is_debug_enabled = False
+        cursor = _make_cursor("Server=localhost;Database=testdb;UID=sa;PWD=pwd", None)
+        cursor._timeout = 0
+
+        captured = _capture_bulkcopy_context(cursor)
+
+        assert "connect_timeout" not in captured
+
+    @patch("mssql_python.cursor.logger")
+    def test_uses_cursor_snapshot_not_live_connection(self, mock_logger):
+        """timeout is the cursor snapshot; later connection changes don't apply."""
+        mock_logger.is_debug_enabled = False
+        cursor = _make_cursor("Server=localhost;Database=testdb;UID=sa;PWD=pwd", None)
+        cursor._timeout = 45
+        cursor._connection.timeout = 99  # changed after cursor creation, must be ignored
+
+        captured = _capture_bulkcopy_context(cursor)
+
+        assert captured.get("connect_timeout") == 45