bug#20629: 25.0.50; Regression: TAGS broken, can't find anything in C++ files.

[Francesco Potortì]

Francesco Potortì wrote:
>> second, if appropriate, match against a tag ::NAME
>> third, regex match against a tag .*::NAME$
>
>Why can we use colons? That implies some sort of knowledge about C++, 
>whereas until now etags.el has remained language-agnostic.

Mh.  I had taken it for given that each major-mode in fact added
something to the list of functions called when looking for a tag.
Doesn't it work that way?  If not, couldn't it be done for languages
where the language-agnostic behaviour of etags.el is not satisfactory?

>> fourth, match against the entry, without looking at the tag
>
>That brings us false positives.

Sure, and in fact I was suggesting it only as a last resort :)