fix uncaught `BdbQuit` exceptions on ipdb `exit`

- `BdbQuit` is now handled in the top-most scope of `InteractiveShell.run_code`. This ensures that `BdbQuit` is correctly handled but can still do its job of breaking out of all user code/loops/further breakpoint requests. Hopefully will work better than previous attempts, which put the `BdqQuit` handling in `Pdb.set_trace`

- fixes:
  - jupyterlab/jupyterlab#12501

- refs:
  - ipython/ipython#876
  - ipython/ipython#1273
  - ipython/ipython#4474
  - ipython/ipython#5306
  - ipython/ipython#9731
  - ipython/ipython#9942
  - ipython/ipython#9950
  - ipython/ipython#10006
  - ipython/ipython#12378

.gitignore

@@ -1,32 +1,40
 MANIFEST
 build
 dist
 _build
 docs/man/*.gz
 docs/source/api/generated
 docs/source/config/options
 docs/source/config/shortcuts/*.csv
 docs/source/savefig
 docs/source/interactive/magics-generated.txt
 docs/gh-pages
 jupyter_notebook/notebook/static/mathjax
 jupyter_notebook/static/style/*.map
 *.py[co]
 __pycache__
 *.egg-info
 *~
 *.bak
 .ipynb_checkpoints
 .tox
 .DS_Store
 \#*#
 .#*
 .cache
 .coverage
 *.swp
 .vscode
 .pytest_cache
 .python-version
 venv*/
-.idea/
 .mypy_cache/
+
+# jetbrains ide stuff
+*.iml
+.idea/
+
+# vscode ide stuff
+*.code-workspace
+.history
+.vscode

IPython/core/debugger.py

@@ -1,1000 +1,999
 # -*- coding: utf-8 -*-
 """
 Pdb debugger class.
 
 
 This is an extension to PDB which adds a number of new features.
 Note that there is also the `IPython.terminal.debugger` class which provides UI
 improvements.
 
 We also strongly recommend to use this via the `ipdb` package, which provides
 extra configuration options.
 
 Among other things, this subclass of PDB:
  - supports many IPython magics like pdef/psource
  - hide frames in tracebacks based on `__tracebackhide__`
  - allows to skip frames based on `__debuggerskip__`
 
 The skipping and hiding frames are configurable via the `skip_predicates`
 command.
 
 By default, frames from readonly files will be hidden, frames containing
 ``__tracebackhide__=True`` will be hidden.
 
 Frames containing ``__debuggerskip__`` will be stepped over, frames who's parent
 frames value of ``__debuggerskip__`` is ``True`` will be skipped.
 
     >>> def helpers_helper():
     ...     pass
     ...
     ... def helper_1():
     ...     print("don't step in me")
     ...     helpers_helpers() # will be stepped over unless breakpoint set.
     ...
     ...
     ... def helper_2():
     ...     print("in me neither")
     ...
 
 One can define a decorator that wraps a function between the two helpers:
 
     >>> def pdb_skipped_decorator(function):
     ...
     ...
     ...     def wrapped_fn(*args, **kwargs):
     ...         __debuggerskip__ = True
     ...         helper_1()
     ...         __debuggerskip__ = False
     ...         result = function(*args, **kwargs)
     ...         __debuggerskip__ = True
     ...         helper_2()
     ...         # setting __debuggerskip__ to False again is not necessary
     ...         return result
     ...
     ...     return wrapped_fn
 
 When decorating a function, ipdb will directly step into ``bar()`` by
 default:
 
     >>> @foo_decorator
     ... def bar(x, y):
     ...     return x * y
 
 
 You can toggle the behavior with
 
     ipdb> skip_predicates debuggerskip false
 
 or configure it in your ``.pdbrc``
 
 
 
 License
 -------
 
 Modified from the standard pdb.Pdb class to avoid including readline, so that
 the command line completion of other programs which include this isn't
 damaged.
 
 In the future, this class will be expanded with improvements over the standard
 pdb.
 
 The original code in this file is mainly lifted out of cmd.py in Python 2.2,
 with minor changes. Licensing should therefore be under the standard Python
 terms.  For details on the PSF (Python Software Foundation) standard license,
 see:
 
 https://docs.python.org/2/license.html
 
 
 All the changes since then are under the same license as IPython.
 
 """
 
 #*****************************************************************************
 #
 #       This file is licensed under the PSF license.
 #
 #       Copyright (C) 2001 Python Software Foundation, www.python.org
 #       Copyright (C) 2005-2006 Fernando Perez. <[e-mail]>
 #
 #
 #*****************************************************************************
 
-import bdb
 import inspect
 import linecache
 import sys
 import warnings
 import re
 import os
 
 from IPython import get_ipython
 from IPython.utils import PyColorize
 from IPython.utils import coloransi, py3compat
 from IPython.core.excolors import exception_colors
 
 # skip module docstests
 __skip_doctest__ = True
 
 prompt = 'ipdb> '
 
 # We have to check this directly from sys.argv, config struct not yet available
 from pdb import Pdb as OldPdb
 
 # Allow the set_trace code to operate outside of an ipython instance, even if
 # it does so with some limitations.  The rest of this support is implemented in
 # the Tracer constructor.
 
 DEBUGGERSKIP = "__debuggerskip__"
 
 
 def make_arrow(pad):
     """generate the leading arrow in front of traceback or debugger"""
     if pad >= 2:
         return '-'*(pad-2) + '> '
     elif pad == 1:
         return '>'
     return ''
 
 
 def BdbQuit_excepthook(et, ev, tb, excepthook=None):
     """Exception hook which handles `BdbQuit` exceptions.
 
     All other exceptions are processed using the `excepthook`
     parameter.
     """
     raise ValueError(
         "`BdbQuit_excepthook` is deprecated since version 5.1",
     )
 
 
 def BdbQuit_IPython_excepthook(self, et, ev, tb, tb_offset=None):
     raise ValueError(
         "`BdbQuit_IPython_excepthook` is deprecated since version 5.1",
         DeprecationWarning, stacklevel=2)
 
 
 RGX_EXTRA_INDENT = re.compile(r'(?<=\n)\s+')
 
 
 def strip_indentation(multiline_string):
     return RGX_EXTRA_INDENT.sub('', multiline_string)
 
 
 def decorate_fn_with_doc(new_fn, old_fn, additional_text=""):
     """Make new_fn have old_fn's doc string. This is particularly useful
     for the ``do_...`` commands that hook into the help system.
     Adapted from from a comp.lang.python posting
     by Duncan Booth."""
     def wrapper(*args, **kw):
         return new_fn(*args, **kw)
     if old_fn.__doc__:
         wrapper.__doc__ = strip_indentation(old_fn.__doc__) + additional_text
     return wrapper
 
 
 class Pdb(OldPdb):
     """Modified Pdb class, does not load readline.
 
     for a standalone version that uses prompt_toolkit, see
     `IPython.terminal.debugger.TerminalPdb` and
     `IPython.terminal.debugger.set_trace()`
 
 
     This debugger can hide and skip frames that are tagged according to some predicates.
     See the `skip_predicates` commands.
 
     """
 
     default_predicates = {
         "tbhide": True,
         "readonly": False,
         "ipython_internal": True,
         "debuggerskip": True,
     }
 
     def __init__(self, completekey=None, stdin=None, stdout=None, context=5, **kwargs):
         """Create a new IPython debugger.
 
         Parameters
         ----------
         completekey : default None
             Passed to pdb.Pdb.
         stdin : default None
             Passed to pdb.Pdb.
         stdout : default None
             Passed to pdb.Pdb.
         context : int
             Number of lines of source code context to show when
             displaying stacktrace information.
         **kwargs
             Passed to pdb.Pdb.
 
         Notes
         -----
         The possibilities are python version dependent, see the python
         docs for more info.
         """
 
         # Parent constructor:
         try:
             self.context = int(context)
             if self.context <= 0:
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError) as e:
                 raise ValueError("Context must be a positive integer") from e
 
         # `kwargs` ensures full compatibility with stdlib's `pdb.Pdb`.
         OldPdb.__init__(self, completekey, stdin, stdout, **kwargs)
 
         # IPython changes...
         self.shell = get_ipython()
 
         if self.shell is None:
             save_main = sys.modules['__main__']
             # No IPython instance running, we must create one
             from IPython.terminal.interactiveshell import \
                 TerminalInteractiveShell
             self.shell = TerminalInteractiveShell.instance()
             # needed by any code which calls __import__("__main__") after
             # the debugger was entered. See also #9941.
             sys.modules["__main__"] = save_main
 
 
         color_scheme = self.shell.colors
 
         self.aliases = {}
 
         # Create color table: we copy the default one from the traceback
         # module and add a few attributes needed for debugging
         self.color_scheme_table = exception_colors()
 
         # shorthands
         C = coloransi.TermColors
         cst = self.color_scheme_table
 
         cst['NoColor'].colors.prompt = C.NoColor
         cst['NoColor'].colors.breakpoint_enabled = C.NoColor
         cst['NoColor'].colors.breakpoint_disabled = C.NoColor
 
         cst['Linux'].colors.prompt = C.Green
         cst['Linux'].colors.breakpoint_enabled = C.LightRed
         cst['Linux'].colors.breakpoint_disabled = C.Red
 
         cst['LightBG'].colors.prompt = C.Blue
         cst['LightBG'].colors.breakpoint_enabled = C.LightRed
         cst['LightBG'].colors.breakpoint_disabled = C.Red
 
         cst['Neutral'].colors.prompt = C.Blue
         cst['Neutral'].colors.breakpoint_enabled = C.LightRed
         cst['Neutral'].colors.breakpoint_disabled = C.Red
 
         # Add a python parser so we can syntax highlight source while
         # debugging.
         self.parser = PyColorize.Parser(style=color_scheme)
         self.set_colors(color_scheme)
 
         # Set the prompt - the default prompt is '(Pdb)'
         self.prompt = prompt
         self.skip_hidden = True
         self.report_skipped = True
 
         # list of predicates we use to skip frames
         self._predicates = self.default_predicates
 
     #
     def set_colors(self, scheme):
         """Shorthand access to the color table scheme selector method."""
         self.color_scheme_table.set_active_scheme(scheme)
         self.parser.style = scheme
 
     def set_trace(self, frame=None):
         if frame is None:
             frame = sys._getframe().f_back
         self.initial_frame = frame
         return super().set_trace(frame)
 
     def _hidden_predicate(self, frame):
         """
         Given a frame return whether it it should be hidden or not by IPython.
         """
 
         if self._predicates["readonly"]:
             fname = frame.f_code.co_filename
             # we need to check for file existence and interactively define
             # function would otherwise appear as RO.
             if os.path.isfile(fname) and not os.access(fname, os.W_OK):
                 return True
 
         if self._predicates["tbhide"]:
             if frame in (self.curframe, getattr(self, "initial_frame", None)):
                 return False
             frame_locals = self._get_frame_locals(frame)
             if "__tracebackhide__" not in frame_locals:
                 return False
             return frame_locals["__tracebackhide__"]
         return False
 
     def hidden_frames(self, stack):
         """
         Given an index in the stack return whether it should be skipped.
 
         This is used in up/down and where to skip frames.
         """
         # The f_locals dictionary is updated from the actual frame
         # locals whenever the .f_locals accessor is called, so we
         # avoid calling it here to preserve self.curframe_locals.
         # Furthermore, there is no good reason to hide the current frame.
         ip_hide = [self._hidden_predicate(s[0]) for s in stack]
         ip_start = [i for i, s in enumerate(ip_hide) if s == "__ipython_bottom__"]
         if ip_start and self._predicates["ipython_internal"]:
             ip_hide = [h if i > ip_start[0] else True for (i, h) in enumerate(ip_hide)]
         return ip_hide
 
     def interaction(self, frame, traceback):
         try:
             OldPdb.interaction(self, frame, traceback)
         except KeyboardInterrupt:
             self.stdout.write("\n" + self.shell.get_exception_only())
 
     def precmd(self, line):
         """Perform useful escapes on the command before it is executed."""
 
         if line.endswith("??"):
             line = "pinfo2 " + line[:-2]
         elif line.endswith("?"):
             line = "pinfo " + line[:-1]
 
         line = super().precmd(line)
 
         return line
 
     def new_do_frame(self, arg):
         OldPdb.do_frame(self, arg)
 
     def new_do_quit(self, arg):
 
         if hasattr(self, 'old_all_completions'):
             self.shell.Completer.all_completions = self.old_all_completions
 
         return OldPdb.do_quit(self, arg)
 
     do_q = do_quit = decorate_fn_with_doc(new_do_quit, OldPdb.do_quit)
 
     def new_do_restart(self, arg):
         """Restart command. In the context of ipython this is exactly the same
         thing as 'quit'."""
         self.msg("Restart doesn't make sense here. Using 'quit' instead.")
         return self.do_quit(arg)
 
     def print_stack_trace(self, context=None):
         Colors = self.color_scheme_table.active_colors
         ColorsNormal = Colors.Normal
         if context is None:
             context = self.context
         try:
             context = int(context)
             if context <= 0:
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError) as e:
                 raise ValueError("Context must be a positive integer") from e
         try:
             skipped = 0
             for hidden, frame_lineno in zip(self.hidden_frames(self.stack), self.stack):
                 if hidden and self.skip_hidden:
                     skipped += 1
                     continue
                 if skipped:
                     print(
                         f"{Colors.excName}    [... skipping {skipped} hidden frame(s)]{ColorsNormal}\n"
                     )
                     skipped = 0
                 self.print_stack_entry(frame_lineno, context=context)
             if skipped:
                 print(
                     f"{Colors.excName}    [... skipping {skipped} hidden frame(s)]{ColorsNormal}\n"
                 )
         except KeyboardInterrupt:
             pass
 
     def print_stack_entry(self, frame_lineno, prompt_prefix='\n-> ',
                           context=None):
         if context is None:
             context = self.context
         try:
             context = int(context)
             if context <= 0:
                 raise ValueError("Context must be a positive integer")
         except (TypeError, ValueError) as e:
                 raise ValueError("Context must be a positive integer") from e
         print(self.format_stack_entry(frame_lineno, '', context), file=self.stdout)
 
         # vds: >>
         frame, lineno = frame_lineno
         filename = frame.f_code.co_filename
         self.shell.hooks.synchronize_with_editor(filename, lineno, 0)
         # vds: <<
 
     def _get_frame_locals(self, frame):
         """ "
         Accessing f_local of current frame reset the namespace, so we want to avoid
         that or the following can happen
 
         ipdb> foo
         "old"
         ipdb> foo = "new"
         ipdb> foo
         "new"
         ipdb> where
         ipdb> foo
         "old"
 
         So if frame is self.current_frame we instead return self.curframe_locals
 
         """
         if frame is self.curframe:
             return self.curframe_locals
         else:
             return frame.f_locals
 
     def format_stack_entry(self, frame_lineno, lprefix=': ', context=None):
         if context is None:
             context = self.context
         try:
             context = int(context)
             if context <= 0:
                 print("Context must be a positive integer", file=self.stdout)
         except (TypeError, ValueError):
                 print("Context must be a positive integer", file=self.stdout)
 
         import reprlib
 
         ret = []
 
         Colors = self.color_scheme_table.active_colors
         ColorsNormal = Colors.Normal
         tpl_link = "%s%%s%s" % (Colors.filenameEm, ColorsNormal)
         tpl_call = "%s%%s%s%%s%s" % (Colors.vName, Colors.valEm, ColorsNormal)
         tpl_line = "%%s%s%%s %s%%s" % (Colors.lineno, ColorsNormal)
         tpl_line_em = "%%s%s%%s %s%%s%s" % (Colors.linenoEm, Colors.line, ColorsNormal)
 
         frame, lineno = frame_lineno
 
         return_value = ''
         loc_frame = self._get_frame_locals(frame)
         if "__return__" in loc_frame:
             rv = loc_frame["__return__"]
             # return_value += '->'
             return_value += reprlib.repr(rv) + "\n"
         ret.append(return_value)
 
         #s = filename + '(' + `lineno` + ')'
         filename = self.canonic(frame.f_code.co_filename)
         link = tpl_link % py3compat.cast_unicode(filename)
 
         if frame.f_code.co_name:
             func = frame.f_code.co_name
         else:
             func = "<lambda>"
 
         call = ""
         if func != "?":
             if "__args__" in loc_frame:
                 args = reprlib.repr(loc_frame["__args__"])
             else:
                 args = '()'
             call = tpl_call % (func, args)
 
         # The level info should be generated in the same format pdb uses, to
         # avoid breaking the pdbtrack functionality of python-mode in *emacs.
         if frame is self.curframe:
             ret.append('> ')
         else:
             ret.append("  ")
         ret.append("%s(%s)%s\n" % (link, lineno, call))
 
         start = lineno - 1 - context//2
         lines = linecache.getlines(filename)
         start = min(start, len(lines) - context)
         start = max(start, 0)
         lines = lines[start : start + context]
 
         for i, line in enumerate(lines):
             show_arrow = start + 1 + i == lineno
             linetpl = (frame is self.curframe or show_arrow) and tpl_line_em or tpl_line
             ret.append(
                 self.__format_line(
                     linetpl, filename, start + 1 + i, line, arrow=show_arrow
                 )
             )
         return "".join(ret)
 
     def __format_line(self, tpl_line, filename, lineno, line, arrow=False):
         bp_mark = ""
         bp_mark_color = ""
 
         new_line, err = self.parser.format2(line, 'str')
         if not err:
             line = new_line
 
         bp = None
         if lineno in self.get_file_breaks(filename):
             bps = self.get_breaks(filename, lineno)
             bp = bps[-1]
 
         if bp:
             Colors = self.color_scheme_table.active_colors
             bp_mark = str(bp.number)
             bp_mark_color = Colors.breakpoint_enabled
             if not bp.enabled:
                 bp_mark_color = Colors.breakpoint_disabled
 
         numbers_width = 7
         if arrow:
             # This is the line with the error
             pad = numbers_width - len(str(lineno)) - len(bp_mark)
             num = '%s%s' % (make_arrow(pad), str(lineno))
         else:
             num = '%*s' % (numbers_width - len(bp_mark), str(lineno))
 
         return tpl_line % (bp_mark_color + bp_mark, num, line)
 
     def print_list_lines(self, filename, first, last):
         """The printing (as opposed to the parsing part of a 'list'
         command."""
         try:
             Colors = self.color_scheme_table.active_colors
             ColorsNormal = Colors.Normal
             tpl_line = '%%s%s%%s %s%%s' % (Colors.lineno, ColorsNormal)
             tpl_line_em = '%%s%s%%s %s%%s%s' % (Colors.linenoEm, Colors.line, ColorsNormal)
             src = []
             if filename == "<string>" and hasattr(self, "_exec_filename"):
                 filename = self._exec_filename
 
             for lineno in range(first, last+1):
                 line = linecache.getline(filename, lineno)
                 if not line:
                     break
 
                 if lineno == self.curframe.f_lineno:
                     line = self.__format_line(
                         tpl_line_em, filename, lineno, line, arrow=True
                     )
                 else:
                     line = self.__format_line(
                         tpl_line, filename, lineno, line, arrow=False
                     )
 
                 src.append(line)
                 self.lineno = lineno
 
             print(''.join(src), file=self.stdout)
 
         except KeyboardInterrupt:
             pass