Re: history distortion

[Manfred Lotz <manfred.lotz@xxxxxxxx>]

On Wed, 12 Feb 2014 15:15:07 -0800
Bart Schaefer <schaefer@xxxxxxxxxxxxxxxx> wrote:

> 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.
> 

Good to know that my observation was right. For the time being I leave
out hist_reduce_blanks till the Fedora zsh package has been updated.

Thanks.


-- 
Manfred