[PATCH v5 1/2] branch: not report invalid tracking branch

@@ -424,19 +424,8 @@ static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
 	struct branch *branch = branch_get(branch_name);
 	struct strbuf fancy = STRBUF_INIT;
 
-	if (!stat_tracking_info(branch, &ours, &theirs)) {
-		if (branch && branch->merge && branch->merge[0]->dst &&
-		    show_upstream_ref) {
-			ref = shorten_unambiguous_ref(branch->merge[0]->dst, 0);
-			if (want_color(branch_use_color))
-				strbuf_addf(stat, "[%s%s%s] ",
-						branch_get_color(BRANCH_COLOR_UPSTREAM),
-						ref, branch_get_color(BRANCH_COLOR_RESET));
-			else
-				strbuf_addf(stat, "[%s] ", ref);
-		}
+	if (!stat_tracking_info(branch, &ours, &theirs))
 		return;
-	}
 
 	if (show_upstream_ref) {
 		ref = shorten_unambiguous_ref(branch->merge[0]->dst, 0);

@@ -448,7 +437,10 @@ static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
 			strbuf_addstr(&fancy, ref);
 	}
 
-	if (!ours) {
+	if (!ours && !theirs) {
+		if (ref)
+			strbuf_addf(stat, _("[%s]"), fancy.buf);
+	} else if (!ours) {
 		if (ref)
 			strbuf_addf(stat, _("[%s: behind %d]"), fancy.buf, theirs);
 		else

@@ -1729,7 +1729,8 @@ int ref_newer(const unsigned char *new_sha1, const unsigned char *old_sha1)
 }
 
 /*
- * Return true if there is anything to report, otherwise false.
+ * Return false if cannot stat a tracking branch (not exist or invalid),
+ * otherwise true.
  */
 int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
 {

@@ -1740,18 +1741,12 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
 	const char *rev_argv[10], *base;
 	int rev_argc;
 
-	/*
-	 * Nothing to report unless we are marked to build on top of
-	 * somebody else.
-	 */
+	/* False unless we are marked to build on top of somebody else. */
 	if (!branch ||
 	    !branch->merge || !branch->merge[0] || !branch->merge[0]->dst)
 		return 0;
 
-	/*
-	 * If what we used to build on no longer exists, there is
-	 * nothing to report.
-	 */
+	/* False if what we used to build on no longer exists */
 	base = branch->merge[0]->dst;
 	if (read_ref(base, sha1))
 		return 0;

@@ -1765,9 +1760,12 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
 	if (!ours)
 		return 0;
 
+	*num_theirs = 0;
+	*num_ours = 0;
+
 	/* are we the same? */
 	if (theirs == ours)
-		return 0;
+		return 1;
 
 	/* Run "rev-list --left-right ours...theirs" internally... */
 	rev_argc = 0;

@@ -1786,8 +1784,6 @@ int stat_tracking_info(struct branch *branch, int *num_ours, int *num_theirs)
 	prepare_revision_walk(&revs);
 
 	/* ... and count the commits on each side. */
-	*num_ours = 0;
-	*num_theirs = 0;
 	while (1) {
 		struct commit *c = get_revision(&revs);
 		if (!c)

@@ -1815,6 +1811,10 @@ 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) {

@@ -1380,15 +1380,24 @@ static void wt_shortstatus_print_tracking(struct wt_status *s)
 	branch = branch_get(s->branch + 11);
 	if (s->is_initial)
 		color_fprintf(s->fp, header_color, _("Initial commit on "));
+
+	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)) {
-		color_fprintf(s->fp, branch_color_local, "%s", branch_name);
+		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, branch_color_local, "%s", branch_name);
 	color_fprintf(s->fp, header_color, "...");
 	color_fprintf(s->fp, branch_color_remote, "%s", base);