Subject: Re: bug#16260: 24.3.50; shell-command-completion and removal of exec-directory from exec-path

From: Lars Ingebrigtsen <[email-masked]>
Date: Wed, 20 Jan 2021 03:35:56 +0100

Eli Zaretskii <[email-masked]> writes:

> shell--command-completion-data has this FIXME comment:
>
>   (defun shell--command-completion-data ()
>     "Return the completion data for the command at point."
>     (let* ((filename (or (comint-match-partial-filename) ""))
> 	   (start (if (zerop (length filename)) (point) (match-beginning 0)))
> 	   (end (if (zerop (length filename)) (point) (match-end 0)))
> 	   (filenondir (file-name-nondirectory filename))
> 	   (path-dirs (cdr (reverse exec-path))) ;FIXME: Why `cdr'?

This code now looks like:

	 (path-dirs
	  ;; Ignore `exec-directory', the last entry in `exec-path'.
          (append (cdr (reverse (exec-path)))
	          (if (and (memq system-type '(windows-nt ms-dos))
                           (not (file-remote-p default-directory)))
                      '("."))))

[...]

> However, just clipping away the last member of exec-path list only
> does TRT in the default case.  It will not work if either of the
> following happens:
>
>   . The user changes epaths.h to specify more than a single directory
>
>   . EMACSPATH is set in the environment
>
> To get this right, we should record at startup time the value of
> exec-path before appending $PATH to it, and then filter out the
> directories recorded at that time in shell--command-completion-data.

I haven't looked further at this (since the FIXME is gone), but it this
something that needs further work?

> As a minor nit, the doc string of shell-dynamic-complete-command
> should not talk about "library path", which is a non-existing term in
> Emacs, but instead mention exec-directory.

This doc string doesn't mention "library path" any more.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no