[PATCH v5 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. What if report upstream tracking info
always even if there is no difference. 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>
---
 remote.c                 | 10 ++++-----
 t/t6040-tracking-info.sh | 54 ++++++++++++++++++++++++++++++++++++++++++++----
 wt-status.c              | 13 +++++-------
 3 files changed, 60 insertions(+), 17 deletions(-)

diff --git a/remote.c b/remote.c
index c747936..70307f4 100644
--- a/remote.c
+++ b/remote.c
@@ -1811,13 +1811,13 @@ int format_tracking_info(struct branch *branch, struct strbuf *sb)
 	if (!stat_tracking_info(branch, &num_ours, &num_theirs))
 		return 0;
 
-	/* Nothing to report if neither side has changes. */
-	if (!num_ours && !num_theirs)
-		return 0;
-
 	base = branch->merge[0]->dst;
 	base = shorten_unambiguous_ref(base, 0);
-	if (!num_theirs) {
+	if (!num_ours && !num_theirs) {
+		strbuf_addf(sb,
+			_("Your branch is identical to '%s'.\n"),
+			base);
+	} else if (!num_theirs) {
 		strbuf_addf(sb,
 			Q_("Your branch is ahead of '%s' by %d commit.\n",
 			   "Your branch is ahead of '%s' by %d commits.\n",
diff --git a/t/t6040-tracking-info.sh b/t/t6040-tracking-info.sh
index ec2b516..eafce7d 100755
--- a/t/t6040-tracking-info.sh
+++ b/t/t6040-tracking-info.sh
@@ -28,18 +28,20 @@ test_expect_success setup '
 		git reset --hard HEAD^ &&
 		git checkout -b b4 origin &&
 		advance e &&
-		advance f
+		advance f &&
+		git checkout -b b5 origin
 	) &&
 	git checkout -b follower --track master &&
 	advance g
 '
 
-script='s/^..\(b.\)[	 0-9a-f]*\[\([^]]*\)\].*/\1 \2/p'
+script='s/^..\(b.\)[	 0-9a-f]*\(\[\([^]]*\)\]\)\{0,1\}.*/\1 \3/p'
 cat >expect <<\EOF
 b1 ahead 1, behind 1
 b2 ahead 1, behind 1
 b3 behind 1
 b4 ahead 2
+b5 
 EOF
 
 test_expect_success 'branch -v' '
@@ -56,6 +58,7 @@ b1 origin/master: ahead 1, behind 1
 b2 origin/master: ahead 1, behind 1
 b3 origin/master: behind 1
 b4 origin/master: ahead 2
+b5 origin/master
 EOF
 
 test_expect_success 'branch -vv' '
@@ -67,20 +70,27 @@ test_expect_success 'branch -vv' '
 	test_i18ncmp expect actual
 '
 
-test_expect_success 'checkout' '
+test_expect_success 'checkout (diverged from upstream)' '
 	(
 		cd test && git checkout b1
 	) >actual &&
 	test_i18ngrep "have 1 and 1 different" actual
 '
 
+test_expect_success 'checkout (identical to upstream)' '
+	(
+		cd test && git checkout b5
+	) >actual &&
+	test_i18ngrep "Your branch is identical to .origin/master" actual
+'
+
 test_expect_success 'checkout with local tracked branch' '
 	git checkout master &&
 	git checkout follower >actual &&
 	test_i18ngrep "is ahead of" actual
 '
 
-test_expect_success 'status' '
+test_expect_success 'status (diverged from upstream)' '
 	(
 		cd test &&
 		git checkout b1 >/dev/null &&
@@ -90,6 +100,42 @@ test_expect_success 'status' '
 	test_i18ngrep "have 1 and 1 different" actual
 '
 
+test_expect_success 'status (identical to upstream)' '
+	(
+		cd test &&
+		git checkout b5 >/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
+
+test_expect_success 'status -s -b (diverged from upstream)' '
+	(
+		cd test &&
+		git checkout b1 >/dev/null &&
+		git status -s -b | head -1
+	) >actual &&
+	test_i18ncmp expect actual
+'
+
+cat >expect <<\EOF
+## b5...origin/master
+EOF
+
+test_expect_success 'status -s -b (identical to upstream)' '
+	(
+		cd test &&
+		git checkout b5 >/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 0c6a3a5..627b59e 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -1383,24 +1383,21 @@ static void wt_shortstatus_print_tracking(struct wt_status *s)
 
 	color_fprintf(s->fp, branch_color_local, "%s", branch_name);
 
-	/*
-	 * Not report tracking info if no tracking branch found
-	 * or no difference found.
-	 */
 	if (!stat_tracking_info(branch, &num_ours, &num_theirs)) {
 		fputc(s->null_termination ? '\0' : '\n', s->fp);
 		return;
 	}
-	if (!num_ours && !num_theirs) {
-		fputc(s->null_termination ? '\0' : '\n', s->fp);
-		return;
-	}
 
 	base = branch->merge[0]->dst;
 	base = shorten_unambiguous_ref(base, 0);
 	color_fprintf(s->fp, header_color, "...");
 	color_fprintf(s->fp, branch_color_remote, "%s", base);
 
+	if (!num_ours && !num_theirs) {
+		fputc(s->null_termination ? '\0' : '\n', s->fp);
+		return;
+	}
+
 	color_fprintf(s->fp, header_color, " [");
 	if (!num_ours) {
 		color_fprintf(s->fp, header_color, _("behind "));
-- 
1.8.4.rc1.430.g417e2f3