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

[Eli Zaretskii]

> Date: Mon, 4 Apr 2016 10:54:14 +0200
> From: Anders Lindgren <andlind@gmail.com>
> Cc: 23179@debbugs.gnu.org
> 
> I just tried your `tags-find-regexp' on Windows, and it failed miserably. It 
> appears to be hanging, but after setting `debug-on-quit' to t and pressing 
> C-g, it always breaks when running an external "grep" command.

Works fine here, without hanging.  Takes circa 9 sec to collect
matches on the entire Emacs tree.

My guess is that you don't have a Find command installed (or it is not
called "find.exe").  Or maybe your Grep is somehow incompatible.

> My conclusion is that starting "grep" on windows is very, very slow compared 
> to opening a temporary buffer and doing re-search-forward.

Well, the only meaningful conclusion that can be drawn from a failed
command is that it doesn't work, not that it's slow.