From 55f88a2581b73d5b38578a756ff90da32a7f01fa 2020-04-21 20:27:09
From: Itamar Turner-Trauring <itamar@itamarst.org>
Date: 2020-04-21 20:27:09
Subject: [PATCH] A maybe better-working interruptible Pdb. Also make separate class so we don't
impact existing usage behavior.

---

diff --git a/IPython/core/debugger.py b/IPython/core/debugger.py
index 8502874..48b24f0 100644
--- a/IPython/core/debugger.py
+++ b/IPython/core/debugger.py
@@ -290,7 +290,7 @@ class Pdb(OldPdb):
         try:
             OldPdb.interaction(self, frame, traceback)
         except KeyboardInterrupt:
-            raise
+            self.stdout.write('\n' + self.shell.get_exception_only())
 
     def new_do_up(self, arg):
         OldPdb.do_up(self, arg)
@@ -627,8 +627,22 @@ class Pdb(OldPdb):
 
     do_w = do_where
 
+
+class InterruptiblePdb(Pdb):
+    """Version of debugger where KeyboardInterrupt exits the debugger altogether."""
+
+    def cmdloop(self):
+        """Wrap cmdloop() such that KeyboardInterrupt stops the debugger."""
+        try:
+            return OldPdb.cmdloop(self)
+        except KeyboardInterrupt:
+            self.stop_here = lambda frame: False
+            self.do_quit("")
+            sys.settrace(None)
+            self.quitting = False
+            raise
+
     def _cmdloop(self):
-        # Variant that doesn't catch KeyboardInterrupts.
         while True:
             try:
                 # keyboard interrupts allow for an easy way to cancel
@@ -638,6 +652,7 @@ class Pdb(OldPdb):
                 self.allow_kbdint = False
                 break
             except KeyboardInterrupt:
+                self.message('--KeyboardInterrupt--')
                 raise
 
 
diff --git a/IPython/core/tests/test_debugger.py b/IPython/core/tests/test_debugger.py
index 4cf7743..6950680 100644
--- a/IPython/core/tests/test_debugger.py
+++ b/IPython/core/tests/test_debugger.py
@@ -13,6 +13,7 @@ from subprocess import check_output, CalledProcessError, PIPE
 import subprocess
 from unittest.mock import patch
 import builtins
+import bdb
 
 import nose.tools as nt
 
@@ -236,11 +237,15 @@ def test_interruptible_core_debugger():
     (this is implemented in ipykernel).  We want to ensure the
     KeyboardInterrupt cause debugging to cease.
     """
-    def raising_input(msg=""):
-        raise KeyboardInterrupt()
+    def raising_input(msg="", called=[0]):
+        called[0] += 1
+        if called[0] == 1:
+            raise KeyboardInterrupt()
+        else:
+            raise AssertionError("input() should only be called once!")
 
     with patch.object(builtins, "input", raising_input):
-        debugger.set_trace()
+        debugger.InterruptiblePdb().set_trace()
         # The way this test will fail is by set_trace() never exiting,
         # resulting in a timeout by the test runner. The alternative
         # implementation would involve a subprocess, but that adds issues with