Issue 199: with cxn: doesn't commit on success

src/connection.cpp

@@ -883,7 +883,12 @@ static PyObject* Connection_enter(PyObject* self)
 static char exit_doc[] = "__exit__(*excinfo) -> None.  Closes the connection.";
 static PyObject* Connection_exit(Connection* cnxn, PyObject* args)
 {
-    Connection_clear(cnxn);
+    // If an error has occurred, `args` will be a tuple of 3 values.  Otherwise it will be a tuple of 3 `None`s.
+    I(PyTuple_Check(args));
+
+    if (cnxn->nAutoCommit == SQL_AUTOCOMMIT_OFF && PyTuple_GetItem(args, 0) == Py_None)
+        SQLEndTran(SQL_HANDLE_DBC, cnxn->hdbc, SQL_COMMIT);
+
     Py_RETURN_NONE;
 }
 

tests/sqlservertests.py

@@ -1232,14 +1232,25 @@ def test_row_gtlt(self):
         rows = list(rows)
         rows.sort() # uses <
 
-    def test_context_manager(self):
-        with pyodbc.connect(self.connection_string) as cnxn:
-            cnxn.getinfo(pyodbc.SQL_DEFAULT_TXN_ISOLATION)
+    def test_context_manager_success(self):
+
+        self.cursor.execute("create table t1(n int)")
+        self.cnxn.commit()
+
+        try:
+            with pyodbc.connect(self.connection_string) as cnxn:
+                cursor = cnxn.cursor()
+                cursor.execute("insert into t1 values (1)")
+        except Exception:
+            pass
+
+        cnxn = None
+        cursor = None
+
+        rows = self.cursor.execute("select n from t1").fetchall()
+        self.assertEquals(len(rows), 1)
+        self.assertEquals(rows[0][0], 1)
 
-        # The connection should be closed now.
-        def test():
-            cnxn.getinfo(pyodbc.SQL_DEFAULT_TXN_ISOLATION)
-        self.assertRaises(pyodbc.ProgrammingError, test)
 
     def test_untyped_none(self):
         # From issue 129