bug#23179: 25.0.92; Restore `M-,' to continue etags search

[Dmitry Gutov]

On 04/04/2016 07:58 PM, Anders Lindgren wrote:

> If xref doesn't provide something similar to tags-search and tags-query
> replace, I would say that it's more likely that Emacs 25.1 will be
> released with M-, bound to tags-loop-continue -- as this will make both
> the old tags commands and the new xref system work. All we need to do is
> to find a new binding for xref-pop-marker-stack.

I find that choice unlikely. But if we do end up butchering the new UI 
to use an amalgam of new and old bindings, I'll leave any further work 
on xref to people with more patience.

>     You've never used e.g. xref-find-references?
>
>
> No. I went into this with the eyes of an existing tags user, and
> reported the problems I saw.

etags has no counterpart for this command. Note, though, that the 
default implementation relies on the Project package.

> However, most Windows users doesn't even have unix tools installed -- so
> it's a really bad idea to assume that tools like `find' and `grep' are
> available when running under Windows (at least until Emacs provide all
> the tools needed).

We've already been assuming their presence for a while, in e.g. rgrep 
and find-grep-dired.

Also, maybe you haven't heard yet: the new version of Windows is 
promised to include a Linux subsystem, with GNU tools installed [0]. It 
should make using Grep, etc, much easier in the long run.

> I think that I have done that. But I'll try again: I would like an
> incremental, UI-free, free text search (like tags-search and
> tags-query-replace). It's up to the backend to decide which files should
> be included in the search. In the tags case, all files referred to the
> tags file should be included. For other environments, public interfaces
> to used libraries could be included.

That's better, thanks. But let's clarify this: should the set of files, 
which is decided by the backend, be exactly the same as the files that 
get searched by xref-find-references? I.e. program source code, in most 
cases.

[0] 
http://www.hanselman.com/blog/DevelopersCanRunBashShellAndUsermodeUbuntuLinuxBinariesOnWindows10.aspx