Empty file execution behavior differs between zsh and sh

[William Shipley <willrandship@xxxxxxxxx>]

In sh and bash

touch true
chmod +x true
./true
echo $?

prints 0, as an empty file returns successfully on execution.

On zsh, the same command returns

zsh: exec format error: ./true

on stderr and

126

for the echo statement.

This holds true when running zsh in sh compatibility mode:

ARGV0=sh zsh

I don't consider this of pressing importance, but it would be one step
closer to sh compatibility.