tags 27772 + patch
severity 27772 minor
quit

Daniel Lopez <daniel.lopez999@gmail.com> writes:

> mkdir foo_files
> cd foo_files
> echo "const int foo_const = 1;" > foo.h
> ctags -e foo.h

Hmm...

    $ ctags -e foo.h 
    ctags: invalid option -- 'e'
        Try 'ctags --help' for a complete list of options.
    $ ctags --version
    ctags (GNU Emacs 25.2.50)
    Copyright (C) 2017 Free Software Foundation, Inc.
    This program is distributed under the terms in ETAGS.README

Using 'etags foo.h' I can reproduce your results.

> I made some incomplete investigations into visit-tags-table-buffer
> where this seems to be implemented - I saw that at one point it seems
> to explicitly look up the local value of tags-file name:
>
>   ;; First, try a local variable.
>   (cdr (assq 'tags-file-name (buffer-local-variables)))
>
> Inspired by that I tried changing the part below where it seems to get
> the value of tags-table-list:
>
>   ;; Fifth, use the user variable giving the table list.
>   ;; Find the first element of the list that actually exists.
>   (let ((list tags-table-list)
>
> to go explicitly via the (buffer-local-variables) alist as well:
>
>   (let ((list (or (cdr (assq 'tags-table-list
> (buffer-local-variables))) tags-table-list))
>
> but it didn't seem to change the outcome of the above test case at
> all.

The problem is that the buffer gets changed by the time we reach there.
The following patch seems to fix it (no need to explicitly use
`buffer-local-variables' since normal variable access will check the
buffer-local value first.  I think the use of `buffer-local-variables'
above is meant to ignore the global value of `tags-file-name').