Fixed #33715 -- Allowed keyboard interrupt to abort queries in MySQL dbshell.

django/db/backends/mysql/client.py

@@ -1,3 +1,5 @@
+import signal
+
 from django.db.backends.base.client import BaseDatabaseClient
 
 
@@ -58,3 +60,13 @@ class DatabaseClient(BaseDatabaseClient):
             args += [database]
         args.extend(parameters)
         return args, env
+
+    def runshell(self, parameters):
+        sigint_handler = signal.getsignal(signal.SIGINT)
+        try:
+            # Allow SIGINT to pass to mysql to abort queries.
+            signal.signal(signal.SIGINT, signal.SIG_IGN)
+            super().runshell(parameters)
+        finally:
+            # Restore the original SIGINT handler.
+            signal.signal(signal.SIGINT, sigint_handler)

tests/dbshell/test_mysql.py

@@ -1,8 +1,11 @@
 import os
+import signal
 import subprocess
 import sys
 from pathlib import Path
+from unittest import mock, skipUnless
 
+from django.db import connection
 from django.db.backends.mysql.client import DatabaseClient
 from django.test import SimpleTestCase
 
@@ -218,3 +221,19 @@ class MySqlDbshellCommandTestCase(SimpleTestCase):
         with self.assertRaises(subprocess.CalledProcessError) as ctx:
             subprocess.run(args, check=True, env=env)
         self.assertNotIn("somepassword", str(ctx.exception))
+
+    @skipUnless(connection.vendor == "mysql", "Requires a MySQL connection")
+    def test_sigint_handler(self):
+        """SIGINT is ignored in Python and passed to mysql to abort queries."""
+
+        def _mock_subprocess_run(*args, **kwargs):
+            handler = signal.getsignal(signal.SIGINT)
+            self.assertEqual(handler, signal.SIG_IGN)
+
+        sigint_handler = signal.getsignal(signal.SIGINT)
+        # The default handler isn't SIG_IGN.
+        self.assertNotEqual(sigint_handler, signal.SIG_IGN)
+        with mock.patch("subprocess.run", new=_mock_subprocess_run):
+            connection.client.runshell([])
+        # dbshell restores the original handler.
+        self.assertEqual(sigint_handler, signal.getsignal(signal.SIGINT))