Merge branch 'jk/maint-reflog-walk-count-vs-time' (early part) into next

"git log -g --format='%gd: %gs' refs/stash" (or worse yet, the same
command line with refs/stash@{0}) was affected by log.date=iso settings
and failed to show stash@{0}, stash@{1},... in the output.  Clarify the
DWIM rules to give the most precedence to how the starting point is
specified (i.e. stash@{0} vs stash@{now}), and then use the presense
of "--date=<format>" command line option as the secondary clue to decide
whether reflog entries are shown with numbers or timestamps.

By Jeff King
* 'jk/maint-reflog-walk-count-vs-time' (early part):
  reflog-walk: always make HEAD@{0} show indexed selectors
  reflog-walk: clean up "flag" field of commit_reflog struct
  log: respect date_mode_explicit with --format:%gd
  t1411: add more selector index/date tests

builtin/rev-list.c

@@ -109,6 +109,7 @@ static void show_commit(struct commit *commit, void *data)
 		struct pretty_print_context ctx = {0};
 		ctx.abbrev = revs->abbrev;
 		ctx.date_mode = revs->date_mode;
+		ctx.date_mode_explicit = revs->date_mode_explicit;
 		ctx.fmt = revs->commit_format;
 		pretty_print_commit(&ctx, commit, &buf);
 		if (revs->graph) {

commit.h

@@ -84,6 +84,7 @@ struct pretty_print_context {
 	const char *after_subject;
 	int preserve_subject;
 	enum date_mode date_mode;
+	unsigned date_mode_explicit:1;
 	int need_8bit_cte;
 	int show_notes;
 	struct reflog_walk_info *reflog_info;

log-tree.c

@@ -652,6 +652,7 @@ void show_log(struct rev_info *opt)
 	if (ctx.need_8bit_cte >= 0)
 		ctx.need_8bit_cte = has_non_ascii(opt->add_signoff);
 	ctx.date_mode = opt->date_mode;
+	ctx.date_mode_explicit = opt->date_mode_explicit;
 	ctx.abbrev = opt->diffopt.abbrev;
 	ctx.after_subject = extra_headers;
 	ctx.preserve_subject = opt->preserve_subject;

pretty.c

@@ -1009,7 +1009,9 @@ static size_t format_commit_one(struct strbuf *sb, const char *placeholder,
 			if (c->pretty_ctx->reflog_info)
 				get_reflog_selector(sb,
 						    c->pretty_ctx->reflog_info,
-						    c->pretty_ctx->date_mode,
+						    c->pretty_ctx->date_mode_explicit ?
+						      c->pretty_ctx->date_mode :
+						      DATE_NORMAL,
 						    (placeholder[1] == 'd'));
 			return 2;
 		case 's':	/* reflog message */

reflog-walk.c

@@ -126,7 +126,12 @@ static void add_commit_info(struct commit *commit, void *util,
 }
 
 struct commit_reflog {
-	int flag, recno;
+	int recno;
+	enum selector_type {
+		SELECTOR_NONE,
+		SELECTOR_INDEX,
+		SELECTOR_DATE
+	} selector;
 	struct complete_reflogs *reflogs;
 };
 
@@ -150,6 +155,7 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 	struct complete_reflogs *reflogs;
 	char *branch, *at = strchr(name, '@');
 	struct commit_reflog *commit_reflog;
+	enum selector_type selector = SELECTOR_NONE;
 
 	if (commit->object.flags & UNINTERESTING)
 		die ("Cannot walk reflogs for %s", name);
@@ -162,7 +168,10 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 		if (*ep != '}') {
 			recno = -1;
 			timestamp = approxidate(at + 2);
+			selector = SELECTOR_DATE;
 		}
+		else
+			selector = SELECTOR_INDEX;
 	} else
 		recno = 0;
 
@@ -200,7 +209,6 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 
 	commit_reflog = xcalloc(sizeof(struct commit_reflog), 1);
 	if (recno < 0) {
-		commit_reflog->flag = 1;
 		commit_reflog->recno = get_reflog_recno_by_time(reflogs, timestamp);
 		if (commit_reflog->recno < 0) {
 			free(branch);
@@ -209,6 +217,7 @@ int add_reflog_for_walk(struct reflog_walk_info *info,
 		}
 	} else
 		commit_reflog->recno = reflogs->nr - recno - 1;
+	commit_reflog->selector = selector;
 	commit_reflog->reflogs = reflogs;
 
 	add_commit_info(commit, commit_reflog, &info->reflogs);
@@ -267,7 +276,8 @@ void get_reflog_selector(struct strbuf *sb,
 	}
 
 	strbuf_addf(sb, "%s@{", printed_ref);
-	if (commit_reflog->flag || 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));
 	} else {

t/t1411-reflog-show.sh

@@ -64,6 +64,14 @@ test_expect_success 'using @{now} syntax shows reflog date (oneline)' '
 	test_cmp expect actual
 '
 
+cat >expect <<'EOF'
+HEAD@{Thu Apr 7 15:13:13 2005 -0700}
+EOF
+test_expect_success 'using @{now} syntax shows reflog date (format=%gd)' '
+	git log -g -1 --format=%gd HEAD@{now} >actual &&
+	test_cmp expect actual
+'
+
 cat >expect <<'EOF'
 Reflog: HEAD@{1112911993 -0700} (C O Mitter <committer@example.com>)
 Reflog message: commit (initial): one
@@ -82,6 +90,51 @@ test_expect_success 'using --date= shows reflog date (oneline)' '
 	test_cmp expect actual
 '
 
+cat >expect <<'EOF'
+HEAD@{1112911993 -0700}
+EOF
+test_expect_success 'using --date= shows reflog date (format=%gd)' '
+	git log -g -1 --format=%gd --date=raw >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+Reflog: HEAD@{0} (C O Mitter <committer@example.com>)
+Reflog message: commit (initial): one
+EOF
+test_expect_success 'log.date does not invoke "--date" magic (multiline)' '
+	test_config log.date raw &&
+	git log -g -1 >tmp &&
+	grep ^Reflog <tmp >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+e46513e HEAD@{0}: commit (initial): one
+EOF
+test_expect_success 'log.date does not invoke "--date" magic (oneline)' '
+	test_config log.date raw &&
+	git log -g -1 --oneline >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+HEAD@{0}
+EOF
+test_expect_success 'log.date does not invoke "--date" magic (format=%gd)' '
+	test_config log.date raw &&
+	git log -g -1 --format=%gd >actual &&
+	test_cmp expect actual
+'
+
+cat >expect <<'EOF'
+HEAD@{0}
+EOF
+test_expect_success '--date magic does not override explicit @{0} syntax' '
+	git log -g -1 --format=%gd --date=raw HEAD@{0} >actual &&
+	test_cmp expect actual
+'
+
 : >expect
 test_expect_success 'empty reflog file' '
 	git branch empty &&