Merge pull request #9950 from mbyt/enable_quit_for_debugging_with_minus_m_IPython.terminal.debugger

Enable quitting for -m IPython.terminal.debugger, which would otherwise unconditionally trap all attempts at exiting.

IPython/terminal/debugger.py

@@ -1,90 +1,96 b''
 from IPython.core.debugger import Pdb
 
 from IPython.core.completer import IPCompleter
 from .ptutils import IPythonPTCompleter
 
 from prompt_toolkit.token import Token
 from prompt_toolkit.shortcuts import create_prompt_application
 from prompt_toolkit.interface import CommandLineInterface
 from prompt_toolkit.enums import EditingMode
 import sys
 
 
 class TerminalPdb(Pdb):
     def __init__(self, *args, **kwargs):
         Pdb.__init__(self, *args, **kwargs)
         self._ptcomp = None
         self.pt_init()
 
     def pt_init(self):
         def get_prompt_tokens(cli):
             return [(Token.Prompt, self.prompt)]
 
         if self._ptcomp is None:
             compl = IPCompleter(shell=self.shell,
                                         namespace={},
                                         global_namespace={},
                                         use_readline=False,
                                         parent=self.shell,
                                        )
             self._ptcomp = IPythonPTCompleter(compl)
 
         self._pt_app = create_prompt_application(
                             editing_mode=getattr(EditingMode, self.shell.editing_mode.upper()),
                             history=self.shell.debugger_history,
                             completer= self._ptcomp,
                             enable_history_search=True,
                             mouse_support=self.shell.mouse_support,
                             get_prompt_tokens=get_prompt_tokens
         )
         self.pt_cli = CommandLineInterface(self._pt_app, eventloop=self.shell._eventloop)
 
     def cmdloop(self, intro=None):
         """Repeatedly issue a prompt, accept input, parse an initial prefix
         off the received input, and dispatch to action methods, passing them
         the remainder of the line as argument.
 
         override the same methods from cmd.Cmd to provide prompt toolkit replacement.
         """
         if not self.use_rawinput:
             raise ValueError('Sorry ipdb does not support use_rawinput=False')
 
         self.preloop()
 
         try:
             if intro is not None:
                 self.intro = intro
             if self.intro:
                 self.stdout.write(str(self.intro)+"\n")
             stop = None
             while not stop:
                 if self.cmdqueue:
                     line = self.cmdqueue.pop(0)
                 else:
                     self._ptcomp.ipy_completer.namespace = self.curframe_locals
                     self._ptcomp.ipy_completer.global_namespace = self.curframe.f_globals
                     try:
                         line = self.pt_cli.run(reset_current_buffer=True).text
                     except EOFError:
                         line = 'EOF'
                 line = self.precmd(line)
                 stop = self.onecmd(line)
                 stop = self.postcmd(stop, line)
             self.postloop()
         except Exception:
             raise
 
 
 def set_trace(frame=None):
     """
     Start debugging from `frame`.
 
     If frame is not specified, debugging starts from caller's frame.
     """
     TerminalPdb().set_trace(frame or sys._getframe().f_back)
 
 
 if __name__ == '__main__':
     import pdb
+    # IPython.core.debugger.Pdb.trace_dispatch shall not catch
+    # bdb.BdbQuit. When started through __main__ and an exception
+    # happened after hitting "c", this is needed in order to
+    # be able to quit the debugging session (see #9950).
+    old_trace_dispatch = pdb.Pdb.trace_dispatch
     pdb.Pdb = TerminalPdb
+    pdb.Pdb.trace_dispatch = old_trace_dispatch
     pdb.main()