[PATCH v8 2/2] status: always show tracking branch even no change

[Jiang Xin <worldhello.net@gmail.com>]

In order to see what the current branch is tracking, one way is using
"git branch -v -v", but branches other than the current are also
reported. Another way is using "git status", such as:

    $ git status
    # On branch master
    # Your branch is ahead of 'origin/master' by 1 commit.
    ...

But this will not work if there is no change between the current
branch and its upstream. Always report upstream tracking info
even if there is no difference, so that "git status" is consistent
for checking tracking info for current branch. E.g.

    $ git status
    # On branch feature1
    # Your branch is identical to 'github/feature1'.
    ...

    $ git status -bs
    ## feature1...github/feature1
    ...

    $ git checkout feature1
    Already on 'feature1'
    Your branch is identical to 'github/feature1'.
    ...

Also add some test cases in t6040.

Signed-off-by: Jiang Xin <worldhello.net@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
 remote.c                 |  7 ++++---
 t/t6040-tracking-info.sh | 34 +++++++++++++++++++++++++++++++++-
 wt-status.c              | 10 +++++-----
 3 files changed, 42 insertions(+), 9 deletions(-)

diff --git a/remote.c b/remote.c
index 87c8dd3..7a8fe3f 100644
--- a/remote.c
+++ b/remote.c
@@ -1788,9 +1788,6 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
 		upstream_is_gone = 1;
 		break;
 	default:
-		/* Nothing to report if neither side has changes. */
-		if (!ours && !theirs)
-			return 0;
 		/* with base */
 		break;
 	}
@@ -1804,6 +1801,10 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
 		if (advice_status_hints)
 			strbuf_addf(sb,
 				_("  (use \"git branch --unset-upstream\" to fixup)\n"));
+	} else if (!ours && !theirs) {
+		strbuf_addf(sb,
+			_("Your branch is identical to '%s'.\n"),
+			base);
 	} else if (!theirs) {
 		strbuf_addf(sb,
 			Q_("Your branch is ahead of '%s' by %d commit.\n",
diff --git a/t/t6040-tracking-info.sh b/t/t6040-tracking-info.sh
index 6f678a4..b24a18c 100755
--- a/t/t6040-tracking-info.sh
+++ b/t/t6040-tracking-info.sh
@@ -32,7 +32,8 @@ test_expect_success setup '
 		git checkout -b brokenbase origin &&
 		git checkout -b b5 --track brokenbase &&
 		advance g &&
-		git branch -d brokenbase
+		git branch -d brokenbase &&
+		git checkout -b b6 origin
 	) &&
 	git checkout -b follower --track master &&
 	advance h
@@ -61,6 +62,7 @@ b2 origin/master: ahead 1, behind 1
 b3 origin/master: behind 1
 b4 origin/master: ahead 2
 b5 brokenbase: gone
+b6 origin/master
 EOF
 
 test_expect_success 'branch -vv' '
@@ -93,6 +95,13 @@ test_expect_success 'checkout (upstream is gone)' '
 	test_i18ngrep "is based on .*, but the upstream is gone." actual
 '
 
+test_expect_success 'checkout (identical to upstream)' '
+	(
+		cd test && git checkout b6
+	) >actual &&
+	test_i18ngrep "Your branch is identical to .origin/master" actual
+'
+
 test_expect_success 'status (diverged from upstream)' '
 	(
 		cd test &&
@@ -113,6 +122,16 @@ test_expect_success 'status (upstream is gone)' '
 	test_i18ngrep "is based on .*, but the upstream is gone." actual
 '
 
+test_expect_success 'status (identical to upstream)' '
+	(
+		cd test &&
+		git checkout b6 >/dev/null &&
+		# reports nothing to commit
+		test_must_fail git commit --dry-run
+	) >actual &&
+	test_i18ngrep "Your branch is identical to .origin/master" actual
+'
+
 cat >expect <<\EOF
 ## b1...origin/master [ahead 1, behind 1]
 EOF
@@ -139,6 +158,19 @@ test_expect_success 'status -s -b (upstream is gone)' '
 	test_i18ncmp expect actual
 '
 
+cat >expect <<\EOF
+## b6...origin/master
+EOF
+
+test_expect_success 'status -s -b (identical to upstream)' '
+	(
+		cd test &&
+		git checkout b6 >/dev/null &&
+		git status -s -b | head -1
+	) >actual &&
+	test_i18ncmp expect actual
+'
+
 test_expect_success 'fail to track lightweight tags' '
 	git checkout master &&
 	git tag light &&
diff --git a/wt-status.c b/wt-status.c
index 4b1713e..c5e6817 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1396,11 +1396,6 @@ static void wt_shortstatus_print_tracking(struct wt_status *s)
 		upstream_is_gone = 1;
 		break;
 	default:
-		/* Stop reporting if neither side has changes. */
-		if (!num_ours && !num_theirs) {
-			fputc(s->null_termination ? '\0' : '\n', s->fp);
-			return;
-		}
 		/* with base */
 		break;
 	}
@@ -1410,6 +1405,11 @@ static void wt_shortstatus_print_tracking(struct wt_status *s)
 	color_fprintf(s->fp, header_color, "...");
 	color_fprintf(s->fp, branch_color_remote, "%s", base);
 
+	if (!upstream_is_gone && !num_ours && !num_theirs) {
+		fputc(s->null_termination ? '\0' : '\n', s->fp);
+		return;
+	}
+
 	color_fprintf(s->fp, header_color, " [");
 	if (upstream_is_gone) {
 		color_fprintf(s->fp, header_color, _("gone"));
-- 
1.8.4.rc3.2.g434fd97