Re: Empty ""s in ARG in ${x:+ARG} expand to no words instead of the empty word if prepended/appended with space

[Bob Proulx]

Denys Vlasenko wrote:
> $ f() { for i; do echo "|$i|"; done; }
> $ x=x
> $ e=
> $ f ${x:+ ""}
> ^^^^^^^^^^^ prints nothing, bug?
> 
> $  ${x:+"" }
> ^^^^^^^^^^^ prints nothing, bug?

Insufficient quoting.  That argument should be quoted to avoid the
whitespace getting stripped.  (Is that during word splitting phase
using the IFS?  I think so.)

Try this:

  f "${x:+ ""}"
  f "${x:+"" }"

Also in the future please say what version of bash you are using.
There have been a lot of bugs fixed in various versions.

Bob