Merge branch 'js/for-each-ref-remote-name-and-ref'

The "--format=..." option "git for-each-ref" takes learned to show
the name of the 'remote' repository and the ref at the remote side
that is affected for 'upstream' and 'push' via "%(push:remotename)"
and friends.

* js/for-each-ref-remote-name-and-ref:
  for-each-ref: test :remotename and :remoteref
  for-each-ref: let upstream/push report the remote ref name
  for-each-ref: let upstream/push optionally report the remote name

This is the final iteration that made it into upstream Git's master
branch and that started out as 8148ee4 (Merge branch
'mingw/ref-filter-remote-name', 2017-10-29).

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Documentation/git-for-each-ref.txt

@@ -145,18 +145,25 @@ upstream::
 	(behind), "<>" (ahead and behind), or "=" (in sync). `:track`
 	also prints "[gone]" whenever unknown upstream ref is
 	encountered. Append `:track,nobracket` 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.
+	information without brackets (i.e "ahead N, behind M").
++
+For any remote-tracking branch `%(upstream)`, `%(upstream:remotename)`
+and `%(upstream:remoteref)` refer to the name of the remote and the
+name of the tracked remote ref, respectively. In other words, the
+remote-tracking branch can be updated explicitly and individually by
+using the refspec `%(upstream:remoteref):%(upstream)` to fetch from
+`%(upstream:remotename)`.
++
+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 for the displayed ref. Respects `:short`, `:lstrip`,
-	`:rstrip`, `:track`, and `:trackshort` options as `upstream`
-	does. Produces an empty string if no `@{push}` ref is
-	configured.
+	`:rstrip`, `:track`, `:trackshort`, `:remotename`, and `:remoteref`
+	options as `upstream` does. Produces an empty string if no `@{push}`
+	ref is configured.
 
 HEAD::
 	'*' if HEAD matches current ref (the checked out branch), ' '

ref-filter.c

@@ -76,9 +76,11 @@ static struct used_atom {
 		char color[COLOR_MAXLEN];
 		struct align align;
 		struct {
-			enum { RR_REF, RR_TRACK, RR_TRACKSHORT } option;
+			enum {
+				RR_REF, RR_TRACK, RR_TRACKSHORT, RR_REMOTE_NAME, RR_REMOTE_REF
+			} option;
 			struct refname_atom refname;
-			unsigned int nobracket : 1;
+			unsigned int nobracket : 1, push : 1, push_remote : 1;
 		} remote_ref;
 		struct {
 			enum { C_BARE, C_BODY, C_BODY_DEP, C_LINES, C_SIG, C_SUB, C_TRAILERS } option;
@@ -138,6 +140,9 @@ static void remote_ref_atom_parser(const struct ref_format *format, struct used_
 	struct string_list params = STRING_LIST_INIT_DUP;
 	int i;
 
+	if (!strcmp(atom->name, "push") || starts_with(atom->name, "push:"))
+		atom->u.remote_ref.push = 1;
+
 	if (!arg) {
 		atom->u.remote_ref.option = RR_REF;
 		refname_atom_parser_internal(&atom->u.remote_ref.refname,
@@ -157,7 +162,13 @@ static void remote_ref_atom_parser(const struct ref_format *format, struct used_
 			atom->u.remote_ref.option = RR_TRACKSHORT;
 		else if (!strcmp(s, "nobracket"))
 			atom->u.remote_ref.nobracket = 1;
-		else {
+		else if (!strcmp(s, "remotename")) {
+			atom->u.remote_ref.option = RR_REMOTE_NAME;
+			atom->u.remote_ref.push_remote = 1;
+		} else if (!strcmp(s, "remoteref")) {
+			atom->u.remote_ref.option = RR_REMOTE_REF;
+			atom->u.remote_ref.push_remote = 1;
+		} else {
 			atom->u.remote_ref.option = RR_REF;
 			refname_atom_parser_internal(&atom->u.remote_ref.refname,
 						     arg, atom->name);
@@ -1268,6 +1279,25 @@ static void fill_remote_ref_details(struct used_atom *atom, const char *refname,
 			*s = ">";
 		else
 			*s = "<>";
+	} else if (atom->u.remote_ref.option == RR_REMOTE_NAME) {
+		int explicit;
+		const char *remote = atom->u.remote_ref.push ?
+			pushremote_for_branch(branch, &explicit) :
+			remote_for_branch(branch, &explicit);
+		if (explicit)
+			*s = xstrdup(remote);
+		else
+			*s = "";
+	} else if (atom->u.remote_ref.option == RR_REMOTE_REF) {
+		int explicit;
+		const char *merge;
+
+		merge = remote_ref_for_branch(branch, atom->u.remote_ref.push,
+					      &explicit);
+		if (explicit)
+			*s = xstrdup(merge);
+		else
+			*s = "";
 	} else
 		die("BUG: unhandled RR_* enum");
 }
@@ -1377,16 +1407,20 @@ static void populate_value(struct ref_array_item *ref)
 			if (refname)
 				fill_remote_ref_details(atom, refname, branch, &v->s);
 			continue;
-		} else if (starts_with(name, "push")) {
+		} else if (atom->u.remote_ref.push) {
 			const char *branch_name;
 			if (!skip_prefix(ref->refname, "refs/heads/",
 					 &branch_name))
 				continue;
 			branch = branch_get(branch_name);
 
-			refname = branch_get_push(branch, NULL);
-			if (!refname)
-				continue;
+			if (atom->u.remote_ref.push_remote)
+				refname = NULL;
+			else {
+				refname = branch_get_push(branch, NULL);
+				if (!refname)
+					continue;
+			}
 			fill_remote_ref_details(atom, refname, branch, &v->s);
 			continue;
 		} else if (starts_with(name, "color:")) {

remote.c

@@ -675,6 +675,36 @@ const char *pushremote_for_branch(struct branch *branch, int *explicit)
 	return remote_for_branch(branch, explicit);
 }
 
+const char *remote_ref_for_branch(struct branch *branch, int for_push,
+				  int *explicit)
+{
+	if (branch) {
+		if (!for_push) {
+			if (branch->merge_nr) {
+				if (explicit)
+					*explicit = 1;
+				return branch->merge_name[0];
+			}
+		} else {
+			const char *dst, *remote_name =
+				pushremote_for_branch(branch, NULL);
+			struct remote *remote = remote_get(remote_name);
+
+			if (remote && remote->push_refspec_nr &&
+			    (dst = apply_refspecs(remote->push,
+						  remote->push_refspec_nr,
+						  branch->refname))) {
+				if (explicit)
+					*explicit = 1;
+				return dst;
+			}
+		}
+	}
+	if (explicit)
+		*explicit = 0;
+	return "";
+}
+
 static struct remote *remote_get_1(const char *name,
 				   const char *(*get_default)(struct branch *, int *))
 {

remote.h

@@ -223,6 +223,8 @@ struct branch {
 struct branch *branch_get(const char *name);
 const char *remote_for_branch(struct branch *branch, int *explicit);
 const char *pushremote_for_branch(struct branch *branch, int *explicit);
+const char *remote_ref_for_branch(struct branch *branch, int for_push,
+				  int *explicit);
 
 int branch_has_merge_config(struct branch *branch);
 int branch_merge_matches(struct branch *, int n, const char *);

t/t6300-for-each-ref.sh

@@ -766,4 +766,36 @@ test_expect_success 'Verify usage of %(symref:rstrip) atom' '
 	test_cmp expected actual
 '
 
+test_expect_success ':remotename and :remoteref' '
+	git init remote-tests &&
+	(
+		cd remote-tests &&
+		test_commit initial &&
+		git remote add from fifth.coffee:blub &&
+		git config branch.master.remote from &&
+		git config branch.master.merge refs/heads/stable &&
+		git remote add to southridge.audio:repo &&
+		git config remote.to.push "refs/heads/*:refs/heads/pushed/*" &&
+		git config branch.master.pushRemote to &&
+		for pair in "%(upstream)=refs/remotes/from/stable" \
+			"%(upstream:remotename)=from" \
+			"%(upstream:remoteref)=refs/heads/stable" \
+			"%(push)=refs/remotes/to/pushed/master" \
+			"%(push:remotename)=to" \
+			"%(push:remoteref)=refs/heads/pushed/master"
+		do
+			echo "${pair#*=}" >expect &&
+			git for-each-ref --format="${pair%=*}" \
+				refs/heads/master >actual &&
+			test_cmp expect actual
+		done &&
+		git branch push-simple &&
+		git config branch.push-simple.pushRemote from &&
+		actual="$(git for-each-ref \
+			--format="%(push:remotename),%(push:remoteref)" \
+			refs/heads/push-simple)" &&
+		test from, = "$actual"
+	)
+'
+
 test_done