bug#38614: 26.3; Info completions in reverse order

[Howard Melman]

I wrote on Sat, 14 Dec 2019:

> When using ivy mode, Info-index shows me the list of
> completions in reverse alphabetical order. Info-menu does too.
> Both Info-index and Info-menu use completing-read with
> Info-complete-menu-item as the collections argument. It
> seems to generate the list in reverse order.
> 
> Sorry this isn't a formatted patch, but a one line fix solves it for me.
> 
> If after this line in Info-complete-menu-item:
>                   (setq completions (delete-dups completions))
> I add this line:
>                   (setq completions (nreverse completions))
> the index and menus are shown in alphabetical order.


My original fix was in the wrong place. It only worked for info files that had 
a single index node (e.g., elisp.info). To work more generally with files with 
several index nodes (e.g., emacs.info) the new line should be just before the 
cache is updated:

              (setq completions (nreverse completions))  ; added fix
              ;; Update the cache.
              (setq Info-complete-cache
                    (list Info-current-file Info-current-node
                          Info-complete-next-re string completions
                          Info-complete-nodes)))
                
I still hope this is considered. The cost of the nreverse here is small, and if 
completion mechanisms sort the list later, they'll find an already sorted list 
will sort faster than the degenerate case of sorting a list already in reverse 
order.

Howard