Fix cases like
eval my-cmd (commandline -o)
complete -C "my-cmd $(commandline -o)"
In both cases, we spuriously evaluate tokens like "(inside-quoted-string)"
as command substitutions. Fix this by escaping the strings. The momentarily
regresses the intended purpose of "eval" -- to expand variables -- but the
next commit will fix that.
This makes it easier to get *any pager* in the number of places we do.
Unfortunately:
1. It can't just execute the pager because that might block
2. We can't really set the necessary options for less here
so they still need to be set outside.
This
Fixes#10074
by falling back to `cat` in that case. We could also decide to abort
instead of using a non-pager, but for history that's probably fine.
