Re: [PATCH 4/4] reflog-walk: always make HEAD@{0} show indexed selectors

[Junio C Hamano <gitster-e+AXbWqSrlAAvxtiuMwx3w@public.gmane.org>]

Jeff King <peff-AdEPDUrAXsQ@public.gmane.org> writes:

> This patch flips the rules to:
>
>   1. if the user asked for ref@{0}, always show the index
>
>   2. if the user asked for ref@{now}, always show the date
>
>   3. otherwise, we have just "ref"; show them counted by
>      default, but respect the presence of "--date" as a clue
>      that the user wanted them date-based

The revision.c parser for "git log --date=default -g master" would flip
the "explicit" bit, revs->date_mode is set to DATE_NORMAL, and that value
will eventually come as dmode here.

> diff --git a/reflog-walk.c b/reflog-walk.c
> index 3549318..b974258 100644
> --- a/reflog-walk.c
> +++ b/reflog-walk.c
> @@ -276,7 +276,8 @@ void get_reflog_selector(struct strbuf *sb,
>  	}
>  
>  	strbuf_addf(sb, "%s@{", printed_ref);
> -	if (commit_reflog->selector == SELECTOR_DATE || dmode) {
> +	if (commit_reflog->selector == SELECTOR_DATE ||
> +	    (commit_reflog->selector == SELECTOR_NONE && dmode)) {
>  		info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
>  		strbuf_addstr(sb, show_date(info->timestamp, info->tz, dmode));

But DATE_NORMAL happens to be zero ;-) "git log --date=default -g master"
would still show the counted version.

I personally do not care about that behaviour, but I know that I will
later later have to deal with people who do care, which is annoying.

Probably we would internally need to define two values to ask for the
DATE_NORMAL output.  Move DATE_NORMAL to non-zero value, introduce a new
DATE_DEFAULT that is zero, and make their output identical, perhaps
something like the attached (not even compile tested).

The implicit comparison to zero in the above is a bad code (but that is
a problem from the very old days).

diff --git a/cache.h b/cache.h
index 58ff054..fe42e80 100644
--- a/cache.h
+++ b/cache.h
@@ -876,7 +876,8 @@ extern struct object *peel_to_type(const char *name, int namelen,
 				   struct object *o, enum object_type);
 
 enum date_mode {
-	DATE_NORMAL = 0,
+	DATE_DEFAULT = 0,
+	DATE_NORMAL,
 	DATE_RELATIVE,
 	DATE_SHORT,
 	DATE_LOCAL,
diff --git a/reflog-walk.c b/reflog-walk.c
index b974258..d002516 100644
--- a/reflog-walk.c
+++ b/reflog-walk.c
@@ -277,7 +277,7 @@ void get_reflog_selector(struct strbuf *sb,
 
 	strbuf_addf(sb, "%s@{", printed_ref);
 	if (commit_reflog->selector == SELECTOR_DATE ||
-	    (commit_reflog->selector == SELECTOR_NONE && dmode)) {
+	    (commit_reflog->selector == SELECTOR_NONE && (dmode != DATE_DEFAULT))) {
 		info = &commit_reflog->reflogs->items[commit_reflog->recno+1];
 		strbuf_addstr(sb, show_date(info->timestamp, info->tz, dmode));
 	} else {