Backport PR #10030: Fix running %run -d twice

I suspect this is a bug in pdb; I'll try to get it fixed there too, but deleting `deb.curframe` seems to work around the issue.

Closes  10028 .

Signed-off-by: Thomas Kluyver <[e-mail]>

IPython/core/magics/execution.py

@@ -806,6 +806,11 b' python-profiler package from non-free.""")'
             self.shell.InteractiveTB.pdb = self.shell.InteractiveTB.debugger_cls()
             deb = self.shell.InteractiveTB.pdb
 
+        # deb.checkline() fails if deb.curframe exists but is None; it can
+        # handle it not existing. https://github.com/ipython/ipython/issues/10028
+        if hasattr(deb, 'curframe'):
+            del deb.curframe
+
         # reset Breakpoint state, which is moronically kept
         # in a class
         bdb.Breakpoint.next = 1

IPython/core/tests/test_run.py

@@ -209,9 +209,16 b' class TestMagicRunPass(tt.TempFileMixin):'
     def test_run_profile( self ):
         """Test that the option -p, which invokes the profiler, do not
         crash by invoking execfile"""
-        _ip = get_ipython()
         self.run_tmpfile_p()
 
+    def test_run_debug_twice(self):
+        # https://github.com/ipython/ipython/issues/10028
+        _ip = get_ipython()
+        with tt.fake_input(['c']):
+            _ip.magic('run -d %s' % self.fname)
+        with tt.fake_input(['c']):
+            _ip.magic('run -d %s' % self.fname)
+
 
 class TestMagicRunSimple(tt.TempFileMixin):
 

IPython/testing/tools.py

@@ -7,16 +7,8 b' Authors'
 
 from __future__ import absolute_import
 
-#-----------------------------------------------------------------------------
-#  Copyright (C) 2009 The IPython Development Team
-#
-#  Distributed under the terms of the BSD License.  The full license is in
-#  the file COPYING, distributed as part of this software.
-#-----------------------------------------------------------------------------
-
-#-----------------------------------------------------------------------------
-# Imports
-#-----------------------------------------------------------------------------
+# Copyright (c) IPython Development Team.
+# Distributed under the terms of the Modified BSD License.
 
 import os
 import re
@@ -26,6 +18,7 b' import tempfile'
 from contextlib import contextmanager
 from io import StringIO
 from subprocess import Popen, PIPE
+from unittest.mock import patch
 
 try:
     # These tools are used by parts of the runtime, so we make the nose
@@ -46,9 +39,6 b' from IPython.utils.encoding import DEFAULT_ENCODING'
 from . import decorators as dec
 from . import skipdoctest
 
-#-----------------------------------------------------------------------------
-# Functions and classes
-#-----------------------------------------------------------------------------
 
 # The docstring for full_path doctests differently on win32 (different path
 # separator) so just skip the doctest there.  The example remains informative.
@@ -444,6 +434,25 b' def make_tempfile(name):'
     finally:
         os.unlink(name)
 
+def fake_input(inputs):
+    """Temporarily replace the input() function to return the given values
+
+    Use as a context manager:
+
+    with fake_input(['result1', 'result2']):
+        ...
+
+    Values are returned in order. If input() is called again after the last value
+    was used, EOFError is raised.
+    """
+    it = iter(inputs)
+    def mock_input(prompt=''):
+        try:
+            return next(it)
+        except StopIteration:
+            raise EOFError('No more inputs given')
+
+    return patch('builtins.input', mock_input)
 
 def help_output_test(subcommand=''):
     """test that `ipython [subcommand] -h` works"""