Location of TAGS table

[Rafal Kurcz]

Hello

How to specify the location of the TAGS table.
The directory with C++ sources is:
/source/

It contains the subdirectory:
/source/extensions/

The tags file is:
/source/TAGS

The following setting in ~/.emacs does not work for me:
(setq tags-file-name '("./TAGS"))

The following setting  works unless I jump to the source file from
extensions/ subdirectory.
Then it prompts me for the location of a TAGS file again.
(setq tags-table-list '("./"))

I would like to tell emacs to locate the TAGS file in a directory I
start emacs from (/source/ in above example).
I would like it to work even in the case when I start emacs as
follows:

cd /source
emacs extensions/file.cpp

visit-tags-table works correct in all above cases but it is a bit
inconvenient to perform that everytime I start emacs.

I don't use tags-file-name and tags-table-list settings in the same
time.


Thank You for help