Re: [PATCH v4] attr: teach "--attr-source=<tree>" global option to "git"

> On Sun, Apr 30, 2023 at 4:39 AM John Cai via GitGitGadget
> <gitgitgadget@gmail.com> wrote:
> 
> > diff --git a/Documentation/git.txt b/Documentation/git.txt
> > index 74973d3cc40..b8f4f604707 100644
> > --- a/Documentation/git.txt
> > +++ b/Documentation/git.txt
> > @@ -212,6 +212,11 @@ If you just want to run git as if it was started in `<path>` then use
> >         nohelpers (exclude helper commands), alias and config
> >         (retrieve command list from config variable completion.commands)
> >
> > +--attr-source=<tree-ish>::
> > +       Read gitattributes from <tree-ish> instead of the worktree. See
> > +       linkgit:gitattributes[5]. This is equivalent to setting the
> > +       `GIT_ATTR_SOURCE` environment variable.
> 
> As you talk about GIT_ATTR_SOURCE, I wonder if this variable should
> also be documented in the "Environment Variables" section of this
> Documentation/git.txt doc.
> 
> > diff --git a/environment.h b/environment.h
> > index a63f0c6a24f..758927a689c 100644
> > --- a/environment.h
> > +++ b/environment.h
> > @@ -55,6 +55,7 @@ const char *getenv_safe(struct strvec *argv, const char *name);
> >  #define GIT_QUARANTINE_ENVIRONMENT "GIT_QUARANTINE_PATH"
> >  #define GIT_OPTIONAL_LOCKS_ENVIRONMENT "GIT_OPTIONAL_LOCKS"
> >  #define GIT_TEXT_DOMAIN_DIR_ENVIRONMENT "GIT_TEXTDOMAINDIR"
> > +#define GIT_ATTR_SOURCE "GIT_ATTR_SOURCE"
> 
> To be similar with the definitions that are just above, I think it
> actually should be:
> 
> #define GIT_ATTR_SOURCE_ENVIRONMENT "GIT_ATTR_SOURCE"
> 
> > @@ -314,6 +315,21 @@ static int handle_options(const char ***argv, int *argc, int *envchanged)
> >                         } else {
> >                                 exit(list_cmds(cmd));
> >                         }
> > +               } else if (!strcmp(cmd, "--attr-source")) {
> > +                       if (*argc < 2) {
> > +                               fprintf(stderr, _("no prefix given for --attr-source\n" ));
> 
> The example I sent was about '--super-prefix' so it made sense to say
> "no prefix given", but here it makes more sense to say something like
> "no attribute source given for --attr-source".
> 

> > +                               usage(git_usage_string);
> > +                       }
> > +                       setenv(GIT_ATTR_SOURCE, (*argv)[1], 1);
> > +                       if (envchanged)
> > +                               *envchanged = 1;
> > +                       (*argv)++;
> > +                       (*argc)--;
> > +               } else if (skip_prefix(cmd, "--attr-source=", &cmd)) {
> > +                       set_git_attr_source(cmd);
> > +                       setenv(GIT_ATTR_SOURCE, (*argv)[1], 1);
> > +                       if (envchanged)
> > +                               *envchanged = 1;
> >                 } else {
> >                         fprintf(stderr, _("unknown option: %s\n"), cmd);
> >                         usage(git_usage_string);