bug#63048: [Home] Shell alias values are not properly quoted

["Ludovic Courtès" <ludovic.courtes@inria.fr>]

Hi!

As Ekaitz reported on Mastodon, shell alias values are not properly
quoted, which causes problem when an alias value contains double-quotes
for instance:

--8<---------------cut here---------------start------------->8---
(define (bash-serialize-aliases field-name val)
  #~(string-append
     #$@(map
         (match-lambda
           ((key . #f)
            "")
           ((key . #t)
            #~(string-append "alias " #$key "\n"))
           ((key . value)
            #~(string-append "alias " #$key "=\"" #$value "\"\n")))
         val)))
--8<---------------cut here---------------end--------------->8---

The solution is to borrow and factorize the code of
‘environment-variable-shell-definitions’, which does it right.

Ludo’.