bpo-27334: roll back transaction if sqlite3 context manager fails to commit (GH-26202)

Co-authored-by: Luca Citi
Co-authored-by: Berker Peksag <berker.peksag@gmail.com>

1 files changed, 21 insertions, 7 deletions

diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
index 8ad5f5f..1bc0455 100644
--- a/Modules/_sqlite/connection.c
+++ b/Modules/_sqlite/connection.c
@@ -1785,17 +1785,31 @@ pysqlite_connection_exit_impl(pysqlite_Connection *self, PyObject *exc_type,
                               PyObject *exc_value, PyObject *exc_tb)
 /*[clinic end generated code: output=0705200e9321202a input=bd66f1532c9c54a7]*/
 {
-    const char* method_name;
+    int commit = 0;
     PyObject* result;
 
     if (exc_type == Py_None && exc_value == Py_None && exc_tb == Py_None) {
-        method_name = "commit";
-    } else {
-        method_name = "rollback";
+        commit = 1;
+        result = pysqlite_connection_commit_impl(self);
     }
-
-    result = PyObject_CallMethod((PyObject*)self, method_name, NULL);
-    if (!result) {
+    else {
+        result = pysqlite_connection_rollback_impl(self);
+    }
+
+    if (result == NULL) {
+        if (commit) {
+            /* Commit failed; try to rollback in order to unlock the database.
+             * If rollback also fails, chain the exceptions. */
+            PyObject *exc, *val, *tb;
+            PyErr_Fetch(&exc, &val, &tb);
+            result = pysqlite_connection_rollback_impl(self);
+            if (result == NULL) {
+                _PyErr_ChainExceptions(exc, val, tb);
+            }
+            else {
+                PyErr_Restore(exc, val, tb);
+            }
+        }
         return NULL;
     }
     Py_DECREF(result);