crash with input longer than line width

I’m using iPython 5.1.0 with the latest prompt_toolkit package (1.0.7). iPython crashes every time I input a line with more characters than my terminal’s current line width. The crash report generated with verbose_crash=True is attached.

Crash_report_ipython.txt

[takluyver]

Pinging @jonathanslenders . Here’s the last couple of frames from the traceback, for convenience:

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/prompt_toolkit/layout/margins.pyc in create_margin(self=<prompt_toolkit.layout.margins.ConditionalMargin object>, cli=<prompt_toolkit.interface.CommandLineInterface object>, window_render_info=<prompt_toolkit.layout.containers.WindowRenderInfo object>, width=8, height=2)
    124     """
    125     def __init__(self, margin, filter):
    126         assert isinstance(margin, Margin)
    127 
    128         self.margin = margin
    129         self.filter = to_cli_filter(filter)
    130 
    131     def get_width(self, cli, ui_content):
    132         if self.filter(cli):
    133             return self.margin.get_width(cli, ui_content)
    134         else:
    135             return 0
    136 
    137     def create_margin(self, cli, window_render_info, width, height):
    138         if width and self.filter(cli):
--> 139             return self.margin.create_margin(cli, window_render_info, width, height)
        self.margin.create_margin = <bound method PromptMargin.create_margin of <prompt_toolkit.layout.margins.PromptMargin object at 0x10d7291d0>>
        cli = <prompt_toolkit.interface.CommandLineInterface object at 0x10d792f50>
        window_render_info = <prompt_toolkit.layout.containers.WindowRenderInfo object at 0x1114b9c90>
        width = 8
        height = 2
    140         else:
    141             return []
    142 
    143 
    144 class ScrollbarMargin(Margin):
    145     """
    146     Margin displaying a scrollbar.
    147 
    148     :param display_arrows: Display scroll up/down arrows.
    149     """
    150     def __init__(self, display_arrows=False):
    151         self.display_arrows = to_cli_filter(display_arrows)
    152 
    153     def get_width(self, cli, ui_content):
    154         return 1

/opt/local/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/prompt_toolkit/layout/margins.pyc in create_margin(self=<prompt_toolkit.layout.margins.PromptMargin object>, cli=<prompt_toolkit.interface.CommandLineInterface object>, window_render_info=<prompt_toolkit.layout.containers.WindowRenderInfo object>, width=8, height=2)
    232         # Next lines. (Show line numbering when numbering is enabled.)
    233         if self.get_continuation_tokens:
    234             tokens2 = self.get_continuation_tokens(cli, width)
    235         else:
    236             tokens2 = []
    237 
    238         show_numbers = self.show_numbers(cli)
    239         last_y = None
    240 
    241         for y in window_render_info.displayed_lines[1:]:
    242             tokens.append((Token, '\n'))
    243             if show_numbers:
    244                 if y != last_y:
    245                     tokens.append((Token.LineNumber, ('%i ' % (y + 1)).rjust(width)))
    246             else:
--> 247                 tokens.extend(tokens2)
        tokens.extend = <built-in method extend of list object at 0x1114bf128>
        tokens2 = None
    248             last_y = y
    249 
    250         return tokens

TypeError: 'NoneType' object is not iterable

[minrk]

IPython in general should try to be resilient against anything user-configurable. One simple option is we could run the prompt once ourselves at startup to validate it.