bug#31796: 26.1; dired-do-find-regexp-and-replace fails to find multiline regexps

[Dmitry Gutov]

On 12.06.2018 13:17, Noam Postavsky wrote:
> As the docstring of dired-do-find-regexp-and-replace says:
>
>      REGEXP should use constructs supported by your local ‘grep’ command.
>
> grep matches single lines, so multiline matching won't work.

*Apparently* 'grep -P -z' can do multiline matches. But I don't know how 
portable that is, and the grep manual calls this combination "experimental".

But if we can, and if we change grep-regexp-alist somehow to support 
\0-delimited results (-P without -z doesn't do multiline), 
xref-matches-in-files could use these flags and get multiline results.

[[:space:]] still wouldn't work, though: it's an Emacs-only extension.