Re: [PATCH 2/2] pretty: use fmt_output_email_subject()

[Jeff King]

On Wed, Mar 01, 2017 at 10:08:10AM -0800, Junio C Hamano wrote:

> >     strbuf_grow(sb, title.len + 1024);
> > -   if (pp->subject) {
> > -           strbuf_addstr(sb, pp->subject);
> > +   if (pp->print_email_subject) {
> > +           if (pp->rev)
> > +                   fmt_output_email_subject(sb, pp->rev);
> 
> A hidden assumption this code makes is that anybody who does not
> want .rev (aka "doing it as part of format-patch that may want
> nr/total etc") does not want _any_ "Subject: ".  It obviously holds
> true in today's code (the one in shortlog-add-commit is the only one
> and it sets an empty string to .subject).
> 
> Does the loss of flexibility to the future callers matter, though?
> I cannot tell offhand.
> 
> Thanks.  Let's see what others think.

I would think that future callers would just need to provide a dummy
pp->rev. I guess that logic could be pushed down into
fmt_output_email_subject(), so that it skips looking at
opt->subject_prefix, etc, when "opt" is NULL, and just hits the
"Subject:" case arm.

I don't think it's a big deal, but it would be easy to fix now, like:

diff --git a/log-tree.c b/log-tree.c
index 4618dd04c..c73df6857 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -334,13 +334,13 @@ void fmt_output_commit(struct strbuf *filename,
 
 void fmt_output_email_subject(struct strbuf *sb, struct rev_info *opt)
 {
-       if (opt->total > 0) {
+       if (opt && opt->total > 0) {
                strbuf_addf(sb, "Subject: [%s%s%0*d/%d] ",
                            opt->subject_prefix,
                            *opt->subject_prefix ? " " : "",
                            digits_in_number(opt->total),
                            opt->nr, opt->total);
-       } else if (opt->total == 0 && opt->subject_prefix && 
*opt->subject_prefix) {
+       } else if (opt && opt->total == 0 && opt->subject_prefix && 
*opt->subject_prefix) {
                strbuf_addf(sb, "Subject: [%s] ",
                            opt->subject_prefix);
        } else {
diff --git a/pretty.c b/pretty.c
index d0f86f5d8..6b321c68c 100644
--- a/pretty.c
+++ b/pretty.c
@@ -1608,8 +1608,7 @@ void pp_title_line(struct pretty_print_context *pp,
 
        strbuf_grow(sb, title.len + 1024);
        if (pp->print_email_subject) {
-               if (pp->rev)
-                       fmt_output_email_subject(sb, pp->rev);
+               fmt_output_email_subject(sb, pp->rev);
                if (needs_rfc2047_encoding(title.buf, title.len, 
RFC2047_SUBJECT))
                        add_rfc2047(sb, title.buf, title.len,
                                                encoding, RFC2047_SUBJECT);

-Peff