Re: history distortion

[Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx>]

On Wed, Feb 12, 2014 at 12:09 PM, Manfred Lotz <manfred.lotz@xxxxxxxx>wrote:

> On Wed, 12 Feb 2014 10:40:45 -0800
> Micah Elliott <mde@xxxxxxxxxxxxxxxx> wrote:
>
> > I was seeing this too, up to a couple months ago (apologies for being
> > too lazy to report). I'm on an Arch rolling release and it's fixed
> > now, so not sure if the problem was specific to the zsh version or
> > something else on the system that updated (saw an earlier thread about
> > a memcmp bug, I think).
>
> I tried out omitting hist_reduce_blanks and it seems that the problem
> doesn't show up.
>

Yes, in zsh prior to 5.0.3 part of the hist_reduce_blanks implementation
was using memcpy on overlapping regions of the command line.  memcpy is
allowed to optimize the copy by moving several bytes at a time, copying
right-to-left instead of left-to-right, etc., so is not safe for overlaps.
 The release of a new shared C library that changed the memcpy
implementation to such an optimized one could break existing zsh installs
when they started dynamically linking against the new library.

This is very likely what happened to you.  The distro you are using will
need to either update zsh or back out the C library incompatibility.