Verifying tags in the wrong file

[Bob Rogers]

   From: Juanma Barranquero <lekktu@gmail.com>
   Date: Wed, 9 Nov 2022 12:46:58 +0100

   M-x load-library <RET> etags <RET>
   M-: (tags-verify-table "any-file-not-tags") <RET>

   It returns nil and leaves behind a buffer visiting the file, in Tags Table
   mode. Not nice, but more or less as expected. Not a bug.

   However, if you verify a (no tags) file already being visited in a buffer,
   it returns nil and *leaves* the buffer in Tags Table mode!

   Well, you'll say, "don't do that". Ok, except that you can do it by
   accident, for example if you're using bs-show and happen to type "t" in the
   wrong line.

   Which, arguably, could be fixed in bs (though I think it's a bug in
   etags.el, not bs.el), except that I don't think there's a
   tags-table-buffer-p or equivalent to check that the buffer contains a Tags
   Table. The way to test it seems to be `tags-verify-table'...

I had a similar issue recently (see bug#54133 [1]) though coming from
buffer-menu-mode.  I would recommend filing a bug report, though the
upshot was that in some situations putting the buffer into
tags-table-mode is TRT, but making it harder to do by accident is also a
good thing.

                                        -- Bob Rogers
                                           http://www.rgrjr.com/

[1]  https://debbugs.gnu.org/cgi/bugreport.cgi?bug=54133