bug#158: Etags completion problem for local tags table

[Francesco Potorti` <pot@gnu.org>]

>> In (at least) emacs 22.1, completing reads for find-tag and list-tags
>> will use the global tags table list even if a local tags file has
>> been specified using a prefix argument for visit-tags-table.
>
>I believe this has already been fixed in the Emacs-23 CVS repository.
>Could you check it?
>
>About the other problems you mentioned, I don't understand enough of
>etags.el's handling of tags-table-list to know what is done on purpose,
>what is a limitation, and what is a bug.  Francesco?

I am not sure what are "the other problems ... mentioned".  Anyway,
regarding the relationship between tags-file-name and tags-table-list, I
always found it confusing.  I see three documentation problems:

First, the help for both variables says that if you set one, you should
not set the other, which is not clear: should one set one or the other?

Second, neither help mentions the visit-tags-table function, which I
think should be the only way to set those variables interactively.

Third, there is no single place where the relationships between the two
variables are described.