bug#53371: 28.0.90; eshell completion error when trying to complete buffer name, args-out-of-range

[Stefan Monnier]

> +      (let ((buffer-p (if (match-beginning 1)
> +                          (equal (match-string 1) "buffer")
>                          t)) ;; buffer-p is non-nil by default.

The comment just describes what the code does but it would be more
useful to explain why.


        Stefan