Completions are rewriting arguments altogether #10904
Description
I think this regression was probably introduced with the commit that tried to make it easier to append to completions (e.g. multiple comma-separated arguments)
> function foo; end
> complete -c foo -s s -l long -xa "hello-world goodbye-friend"
> complete -C"foo -s frien"
goodbye-friend # ok
> complete -C"foo -shell"
-shello-world # good
> complete -C"foo -sfrie"
goodbye-friend # bad
> complete -C"foo --long hel"
hello-world # ok
> complete -C"foo --long fr"
goodbye-friend # ok
> complete -C"foo --long=hell"
--long=hello-world # good
> complete -C"foo --long=frien"
goodbye-friend # bad