[Bug] Doubled completions with suffix aliases and grouping

[Guido Cella <guidocella91@xxxxxxxxx>]

[Bug] Doubled completions with suffix aliases and grouping
When completion grouping is enabled and a directory contains only regular files whose suffixes have aliases defined, file completions are listed twice. This seems to be caused by the fact that when there are no executables or directories to complete, zsh completes every file in the directory (grouped as "executable file"), and only later adds files that match suffix aliases.

This can be reproduced with:
alias -s txt=$EDITOR
autoload compinit
compinit
zstyle ':completion:*' group-name ''
zstyle ':completion:*:descriptions' format '%F{yellow}%B%d%b%f'
mkdir /tmp/foo
cd /tmp/foo
: >{1..9}.txt
./<Tab>