On Wed, Nov 11, 2020 at 10:04 AM Felipe Contreras <
felipe.contreras@gmail.com> wrote:

>
> And what is the reason why this is not the default?
>

Remember that doc Daniel quoted?

30 years-ish ago, when implementing zsh as a new shell from scratch, that
documentation was used to decide the behavior.  At that point the other
shells that supported "typeset" were not freeware -- they required
expensive licenses or were bundled with commercial operating systems.  So
the implementation followed the doc (sometimes, it followed a
misunderstanding of the doc, which is why for example zsh syntax to specify
integer bases differs from ksh) without examples to which to compare.

Zsh development has always followed a principle of NOT arbitrarily breaking
past usage without an extremely good reason (something I wish other APIs
would have taken to heart over the years ... IMO there would be much less
abandonware sitting in metaphorical dustbins ... but I digress).  So by the
time anyone noticed, the behavior you see now was standard practice for zsh
in its default modes.

Your original example can use ${var:-other} if empty string has no explicit
meaning in context.

Either way, if "emulate ksh" is supposed to emulate ksh, then it's not
> working properly in this instance.
>

Despite the name, "emulate ksh" is not supposed to perfectly emulate ksh.
All it does is change the values of "setopt" to match ksh as closely as
possible.  A more complete emulation is achieved by actually starting zsh
from a symlink named "ksh" (or one of a few equivalent ways).  Same goes
for "sh" and "bash" (although there is little difference for those two).