Re: [Emacs-diffs] master 55ec674: * lisp/multifile.el: New file, extracted from etags.el

[Dmitry Gutov]

On 18.01.2019 15:49, Stefan Monnier wrote:
> > I'm not adding this to master because this does not support
> > project-vc-ignores (or grep-find-ignored-files).
>
> Not sure why you think it should obey grep-find-ignored-files, but

You're probably right, .gitignore should already include the necessary 
entries anyway. I'll simplify the definition of project-ignores for the 
vc backend.

> I think the project-vc-ignores variable is an error: project-vc-ignores
> should be a function that returns the set of files ignored by the
> underlying VCS, not something that the user sets in Emacs.

You're thinking of project-ignores. project-vc-ignores is a variable for 
the user to be able to tweak that list. Other editors such as Atom and 
VS Code have a section in the preferences for this, but

The sets of files that are checked into the repository and the files 
that the user might like to visit or search are not necessarily the same.

For instance, it's common practice where I work to check in sample 
config files and add the "real" file names to the ignores. Example: 
database.yml.sample is checked into Git, and database.yml is in 
gitignore (this file the user creates locally using the sample file as 
an example). But they'll want to visit and search that file anyway.

And vice versa, there can be files inside the repository which the 
particular user would prefer to ignore most of the time. For me, that's 
usually web assets, minified JS libs, etc (I don't write JS these days 
anyway) and files with recorded HTTP interactions (there are lots of 
them, and they have very long names, so any fuzzy search against file 
names would often hit several of them, slowing ido-find-file down).

Further, we might even choose not to use .gitignore contents in this 
operation and simply filter out some standard list (plus globs defined 
by user preference). Because if somebody decides to implement a file 
explorer using project-files, or only visit files using 
project-find-file, they might be surprised to see certain files missing. 
Not all ignored files are machine-generated, and even those need to be 
verified sometimes.