Fix pdb expression output leaking to debuggee stdout

Author: shreyadesai20042009

Lib/pdb.py

@@ -888,7 +888,7 @@ def _exec_in_closure(self, source, globals, locals):
         locals.update(pdb_eval["write_back"])
         eval_result = pdb_eval["result"]
         if eval_result is not None:
-            print(repr(eval_result))
+            self.message(repr(eval_result))
 
         return True
 

Lib/test/test_remote_pdb.py

@@ -1007,6 +1007,28 @@ def side_effect(line):
             prompts = [o for o in outputs if 'prompt' in o]
             self.assertEqual(len(prompts), 2)  # Should have sent 2 prompts
 
+    def test_expression_evaluation_output(self):
+        """Test that expression evaluation results are sent through the socket, not to debuggee stdout."""
+        # Test lambda expression
+        self.pdb.default("(lambda: 123)()")
+        
+        outputs = self.sockfile.get_output()
+        # Should have a message with the result
+        messages = [o for o in outputs if 'message' in o]
+        self.assertTrue(any('123' in o.get('message', '') for o in messages),
+                        f"Expected '123' in output messages, got: {messages}")
+
+    def test_expression_evaluation_sum(self):
+        """Test that sum expression evaluation results are sent through the socket."""
+        # Test sum expression
+        self.pdb.default("sum(i for i in (1, 2, 3))")
+        
+        outputs = self.sockfile.get_output()
+        # Should have a message with the result
+        messages = [o for o in outputs if 'message' in o]
+        self.assertTrue(any('6' in o.get('message', '') for o in messages),
+                        f"Expected '6' in output messages, got: {messages}")
+
 
 @requires_subprocess()
 @unittest.skipIf(is_wasi, "WASI does not support TCP sockets")