ref-filter: add support for %(upstream:track,nobracket)

Add support for %(upstream:track,nobracket) which will print the
tracking information without the brackets (i.e. "ahead N, behind M").
This is needed when we port branch.c to use ref-filter's printing APIs.

Add test and documentation for the same.

Mentored-by: Christian Couder <christian.couder@gmail.com>
Mentored-by: Matthieu Moy <matthieu.moy@grenoble-inp.fr>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-for-each-ref.txt

@@ -120,9 +120,13 @@ upstream::
 	`refname` above.  Additionally respects `:track` to show
 	"[ahead N, behind M]" and `:trackshort` to show the terse
 	version: ">" (ahead), "<" (behind), "<>" (ahead and behind),
-	or "=" (in sync).  Has no effect if the ref does not have
+	or "=" (in sync). `:track` also prints "[gone]" whenever
-	tracking information associated with it. `:track` also prints
+	unknown upstream ref is encountered. Append `:track,nobracket`
-	"[gone]" whenever unknown upstream ref is encountered.
+	to show tracking information without brackets (i.e "ahead N,
+	behind M").  Has no effect if the ref does not have tracking
+	information associated with it.  All the options apart from
+	`nobracket` are mutually exclusive, but if used together the
+	last option is selected.
 
 push::
 	The name of a local ref which represents the `@{push}` location

ref-filter.c

@@ -48,8 +48,10 @@ static struct used_atom {
 	union {
 		char color[COLOR_MAXLEN];
 		struct align align;
-		enum { RR_NORMAL, RR_SHORTEN, RR_TRACK, RR_TRACKSHORT }
+		struct {
-			remote_ref;
+			enum { RR_NORMAL, RR_SHORTEN, RR_TRACK, RR_TRACKSHORT } option;
+			unsigned int nobracket : 1;
+		} remote_ref;
 		struct {
 			enum { C_BARE, C_BODY, C_BODY_DEP, C_LINES, C_SIG, C_SUB, C_TRAILERS } option;
 			unsigned int nlines;
@@ -77,16 +79,33 @@ static void color_atom_parser(struct used_atom *atom, const char *color_value)
 
 static void remote_ref_atom_parser(struct used_atom *atom, const char *arg)
 {
-	if (!arg)
+	struct string_list params = STRING_LIST_INIT_DUP;
-		atom->u.remote_ref = RR_NORMAL;
+	int i;
-	else if (!strcmp(arg, "short"))
+
-		atom->u.remote_ref = RR_SHORTEN;
+	if (!arg) {
-	else if (!strcmp(arg, "track"))
+		atom->u.remote_ref.option = RR_NORMAL;
-		atom->u.remote_ref = RR_TRACK;
+		return;
-	else if (!strcmp(arg, "trackshort"))
+	}
-		atom->u.remote_ref = RR_TRACKSHORT;
+
+	atom->u.remote_ref.nobracket = 0;
+	string_list_split(&params, arg, ',', -1);
+
+	for (i = 0; i < params.nr; i++) {
+		const char *s = params.items[i].string;
+
+		if (!strcmp(s, "short"))
+			atom->u.remote_ref.option = RR_SHORTEN;
+		else if (!strcmp(s, "track"))
+			atom->u.remote_ref.option = RR_TRACK;
+		else if (!strcmp(s, "trackshort"))
+			atom->u.remote_ref.option = RR_TRACKSHORT;
+		else if (!strcmp(s, "nobracket"))
+			atom->u.remote_ref.nobracket = 1;
 		else
 			die(_("unrecognized format: %%(%s)"), atom->name);
+	}
+
+	string_list_clear(&params, 0);
 }
 
 static void body_atom_parser(struct used_atom *atom, const char *arg)
@@ -1069,25 +1088,27 @@ static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
 				    struct branch *branch, const char **s)
 {
 	int num_ours, num_theirs;
-	if (atom->u.remote_ref == RR_SHORTEN)
+	if (atom->u.remote_ref.option == RR_SHORTEN)
 		*s = shorten_unambiguous_ref(refname, warn_ambiguous_refs);
-	else if (atom->u.remote_ref == RR_TRACK) {
+	else if (atom->u.remote_ref.option == RR_TRACK) {
 		if (stat_tracking_info(branch, &num_ours,
 				       &num_theirs, NULL)) {
-			*s = "[gone]";
+			*s = xstrdup("gone");
-			return;
+		} else if (!num_ours && !num_theirs)
-		}
-
-		if (!num_ours && !num_theirs)
 			*s = "";
 		else if (!num_ours)
-			*s = xstrfmt("[behind %d]", num_theirs);
+			*s = xstrfmt("behind %d", num_theirs);
 		else if (!num_theirs)
-			*s = xstrfmt("[ahead %d]", num_ours);
+			*s = xstrfmt("ahead %d", num_ours);
 		else
-			*s = xstrfmt("[ahead %d, behind %d]",
+			*s = xstrfmt("ahead %d, behind %d",
 				     num_ours, num_theirs);
-	} else if (atom->u.remote_ref == RR_TRACKSHORT) {
+		if (!atom->u.remote_ref.nobracket && *s[0]) {
+			const char *to_free = *s;
+			*s = xstrfmt("[%s]", *s);
+			free((void *)to_free);
+		}
+	} else if (atom->u.remote_ref.option == RR_TRACKSHORT) {
 		if (stat_tracking_info(branch, &num_ours,
 				       &num_theirs, NULL))
 			return;

t/t6300-for-each-ref.sh

@@ -372,6 +372,8 @@ test_expect_success 'setup for upstream:track[short]' '
 
 test_atom head upstream:track '[ahead 1]'
 test_atom head upstream:trackshort '>'
+test_atom head upstream:track,nobracket 'ahead 1'
+test_atom head upstream:nobracket,track 'ahead 1'
 test_atom head push:track '[ahead 1]'
 test_atom head push:trackshort '>'