pythongh-130660: Add a test for pdb when user quits after interact command (python#130852)

Author: gaogaotiantian

Lib/test/test_pdb.py

@@ -4342,6 +4342,32 @@ def test_quit(self):
         # The quit prompt should be printed exactly twice
         self.assertEqual(stdout.count("Quit anyway"), 2)
 
+    def test_quit_after_interact(self):
+        """
+        interact command will set sys.ps1 temporarily, we need to make sure
+        that it's restored and pdb does not believe it's in interactive mode
+        after interact is done.
+        """
+        script = """
+            x = 1
+            breakpoint()
+        """
+
+        commands = """
+            interact
+            quit()
+            q
+            y
+        """
+
+        stdout, stderr = self._run_script(script, commands)
+        # Normal exit should not print anything to stderr
+        self.assertEqual(stderr, "")
+        # The quit prompt should be printed exactly once
+        self.assertEqual(stdout.count("Quit anyway"), 1)
+        # BdbQuit should not be printed
+        self.assertNotIn("BdbQuit", stdout)
+
     def test_set_trace_with_skip(self):
         """GH-82897
         Inline set_trace() should break unconditionally. This example is a