[9front] Re: sed: fix moving '^' match

[Anthony Martin <ality@pbrane.org>]

ori@eigenstate.org once said:
> Currently, if you do something like:
>
> 	echo aabbccd | sed s/^..//g
>
> it will output simply:
>
> 	'd'
>
> [...]
>
> This patch works by adding a dummy character
> at the start of the line, so we aren't at
> the start of a line after the first sub.
>
> [...]
>
> anyone aware of any unexpected side effets
> that this may have?

It looks like a reasonable change but I'd be hesitant to
make it. Ed(1) produces the same output and the behavior
appears to be unchanged since at least the 8th edition.

It's clearly a rare edge case and easily avoided by not using
the g flag when it's not necessary. I doubt it would break
anything, though.

Cheers,
  Anthony