ipython history causes segfault on embedded powerpc

[zutje]

I notice that ipython segfaults on the following conditions:

• no SQLite
• a command is not found in the history list when arrow-up is pressed.

The following snapshots apply:

ipython

WARNING: IPython History requires SQLite, your history will not be saved
Python 2.7.9 (default, Mar 17 2015, 11:45:11)

It crashes in this case nothing with "rela" is found in the history:

In [17]: relapython[1380]: unhandled signal 11 at 00000000 nip b6b10940 lr b6b10934 code 30001
Segmentation fault

System is MPC8313E, powerpc
Buildroot, uclibc, linux 3.18, busybox shell

Since the history works when commands are present and there is a match found. Also on startup when pressing the "up" key ipython segfaults. It looks to me that somehow a pointer is not set up correctly when SQLite is not present (which on an embedded system can be the case due to space restrictions).

The problem for me is that I can not exclude yet that something in the cross compiler stuff might be the cause, although the rest of the system seems to be working fine and stable.

[zutje]

I noticed this does not occur when no start of a string is entered, only when entering the start of a search string.

[takluyver]

The up/down arrow keys for history search are handled by readline - I suspect IPython's settings are revealing a bug in there. You can override IPython's defaults for readline by setting other actions for those keys in ~/.inputrc, or in IPython config by setting InteractiveShell.readline_parse_and_bind.

[zutje]

Dear Thomas,

On 19-03-15 17:54, Thomas Kluyver wrote:

The up/down arrow keys for history search are handled by readline - I
suspect IPython's settings are revealing a bug in there. You can
override IPython's defaults for readline by setting other actions for
those keys in |~/.inputrc|, or in IPython config by setting
|InteractiveShell.readline_parse_and_bind|.

I have set InteractiveShell.readline_parse_and_bind=[] and the problem
is gone. How do I best report this to the readline people since I have
no idea how IPython uses readline.

Best regards,

Tjeerd

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[takluyver]

The readline guidelines for bug reporting are here: http://cnswww.cns.cwru.edu/php/chet/readline/rltop.html#Bugs

The relevant option that we're setting for the up arrow is :

"\e[A": history-search-backward

If I'm correct that this is a readline bug, then it should be possible to trigger the same bug in bash or any other shell using readline by putting that line in your ~/.inputrc.

Thanks!