branch.c: use 'ref-filter' APIs

Make 'branch.c' use 'ref-filter' APIs for iterating through refs
sorting. This removes most of the code used in 'branch.c' replacing it
with calls to the 'ref-filter' library.

Make 'branch.c' use the 'filter_refs()' function provided by 'ref-filter'
to filter out tags based on the options set.

We provide a sorting option provided for 'branch.c' by using the
sorting options provided by 'ref-filter'. Also by default, we sort by
'refname'.  Since 'HEAD' is alphabatically before 'refs/...' we end up
with an array consisting of the 'HEAD' ref then the local branches and
finally the remote-tracking branches.

Also remove the 'ignore' variable from ref_array_item as it was
previously used for the '--merged' option and now that is handled by
ref-filter.

Modify some of the tests in t1430 to check the stderr for a warning
regarding the broken ref. This is done as ref-filter throws a warning
for broken refs rather than directly printing them.

Add tests 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>

6 files changed, 78 insertions, 192 deletions

diff --git a/Documentation/git-branch.txt b/Documentation/git-branch.txt
index a67138a02..c45295d98 100644
--- a/Documentation/git-branch.txt
+++ b/Documentation/git-branch.txt
@@ -11,7 +11,7 @@ SYNOPSIS
 'git branch' [--color[=<when>] | --no-color] [-r | -a]
 	[--list] [-v [--abbrev=<length> | --no-abbrev]]
 	[--column[=<options>] | --no-column]
-	[(--merged | --no-merged | --contains) [<commit>]] [<pattern>...]
+	[(--merged | --no-merged | --contains) [<commit>]] [--sort=<key>] [<pattern>...]
 'git branch' [--set-upstream | --track | --no-track] [-l] [-f] <branchname> [<start-point>]
 'git branch' (--set-upstream-to=<upstream> | -u <upstream>) [<branchname>]
 'git branch' --unset-upstream [<branchname>]
@@ -229,6 +229,16 @@ start-point is either a local or remote-tracking branch.
 	The new name for an existing branch. The same restrictions as for
 	<branchname> apply.
 
+--sort=<key>::
+	Sort based on the key given. Prefix `-` to sort in descending
+	order of the value. You may use the --sort=<key> option
+	multiple times, in which case the last key becomes the primary
+	key. The keys supported are the same as those in `git
+	for-each-ref`. Sort order defaults to sorting based on the
+	full refname (including `refs/...` prefix). This lists
+	detached HEAD (if present) first, then local branches and
+	finally remote-tracking branches.
+
 
 Examples
 --------
diff --git a/builtin/branch.c b/builtin/branch.c
index bfbba2f8d..b83116a60 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -270,125 +270,6 @@ static int delete_branches(int argc, const char **argv, int force, int kinds,
 	return(ret);
 }
 
-static char *resolve_symref(const char *src, const char *prefix)
-{
-	unsigned char sha1[20];
-	int flag;
-	const char *dst;
-
-	dst = resolve_ref_unsafe(src, 0, sha1, &flag);
-	if (!(dst && (flag & REF_ISSYMREF)))
-		return NULL;
-	if (prefix)
-		skip_prefix(dst, prefix, &dst);
-	return xstrdup(dst);
-}
-
-static int match_patterns(const char **pattern, const char *refname)
-{
-	if (!*pattern)
-		return 1; /* no pattern always matches */
-	while (*pattern) {
-		if (!wildmatch(*pattern, refname, 0, NULL))
-			return 1;
-		pattern++;
-	}
-	return 0;
-}
-
-/*
- * Allocate memory for a new ref_array_item and insert that into the
- * given ref_array. Doesn't take the objectname unlike
- * new_ref_array_item(). This is a temporary function which will be
- * removed when we port branch.c to use ref-filter APIs.
- */
-static struct ref_array_item *ref_array_append(struct ref_array *array, const char *refname)
-{
-	size_t len = strlen(refname);
-	struct ref_array_item *ref = xcalloc(1, sizeof(struct ref_array_item) + len + 1);
-	memcpy(ref->refname, refname, len);
-	ref->refname[len] = '\0';
-	REALLOC_ARRAY(array->items, array->nr + 1);
-	array->items[array->nr++] = ref;
-	return ref;
-}
-
-static int append_ref(const char *refname, const struct object_id *oid, int flags, void *cb_data)
-{
-	struct ref_filter_cbdata *cb = (struct ref_filter_cbdata *)(cb_data);
-	struct ref_filter *filter = cb->filter;
-	struct ref_array *array = cb->array;
-	struct ref_array_item *item;
-	struct commit *commit;
-	int kind, i;
-	const char *prefix, *orig_refname = refname;
-
-	static struct {
-		int kind;
-		const char *prefix;
-	} ref_kind[] = {
-		{ FILTER_REFS_BRANCHES, "refs/heads/" },
-		{ FILTER_REFS_REMOTES, "refs/remotes/" },
-	};
-
-	/* Detect kind */
-	for (i = 0; i < ARRAY_SIZE(ref_kind); i++) {
-		prefix = ref_kind[i].prefix;
-		if (skip_prefix(refname, prefix, &refname)) {
-			kind = ref_kind[i].kind;
-			break;
-		}
-	}
-	if (ARRAY_SIZE(ref_kind) <= i) {
-		if (!strcmp(refname, "HEAD"))
-			kind = FILTER_REFS_DETACHED_HEAD;
-		else
-			return 0;
-	}
-
-	/* Don't add types the caller doesn't want */
-	if ((kind & filter->kind) == 0)
-		return 0;
-
-	if (!match_patterns(filter->name_patterns, refname))
-		return 0;
-
-	commit = NULL;
-	if (filter->verbose || filter->with_commit || filter->merge != REF_FILTER_MERGED_NONE) {
-		commit = lookup_commit_reference_gently(oid->hash, 1);
-		if (!commit)
-			return 0;
-
-		/* Filter with with_commit if specified */
-		if (!is_descendant_of(commit, filter->with_commit))
-			return 0;
-
-		if (filter->merge != REF_FILTER_MERGED_NONE)
-			add_pending_object(array->revs,
-					   (struct object *)commit, refname);
-	}
-
-	item = ref_array_append(array, refname);
-
-	/* Record the new item */
-	item->kind = kind;
-	item->commit = commit;
-	item->symref = resolve_symref(orig_refname, prefix);
-	item->ignore = 0;
-
-	return 0;
-}
-
-static int ref_cmp(const void *r1, const void *r2)
-{
-	struct ref_array_item *c1 = *((struct ref_array_item **)r1);
-	struct ref_array_item *c2 = *((struct ref_array_item **)r2);
-
-	if (c1->kind != c2->kind)
-		return c1->kind - c2->kind;
-	return strcmp(c1->refname, c2->refname);
-}
-
 static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
 		int show_upstream_ref)
 {
@@ -452,7 +333,7 @@ static void fill_tracking_info(struct strbuf *stat, const char *branch_name,
 }
 
 static void add_verbose_info(struct strbuf *out, struct ref_array_item *item,
-			     struct ref_filter *filter)
+			     struct ref_filter *filter, const char *refname)
 {
 	struct strbuf subject = STRBUF_INIT, stat = STRBUF_INIT;
 	const char *sub = _(" **** invalid ref ****");
@@ -464,7 +345,7 @@ static void add_verbose_info(struct strbuf *out, struct ref_array_item *item,
 	}
 
 	if (item->kind == FILTER_REFS_BRANCHES)
-		fill_tracking_info(&stat, item->refname, filter->verbose > 1);
+		fill_tracking_info(&stat, refname, filter->verbose > 1);
 
 	strbuf_addf(out, " %s %s%s",
 		find_unique_abbrev(item->commit->object.sha1, filter->abbrev),
@@ -504,8 +385,8 @@ static char *get_head_description(void)
 	return strbuf_detach(&desc, NULL);
 }
 
-static void print_ref_item(struct ref_array_item *item, int maxwidth,
-			   struct ref_filter *filter, const char *remote_prefix)
+static void format_and_print_ref_item(struct ref_array_item *item, int maxwidth,
+				      struct ref_filter *filter, const char *remote_prefix)
 {
 	char c;
 	int current = 0;
@@ -515,17 +396,16 @@ static void print_ref_item(struct ref_array_item *item, int maxwidth,
 	const char *desc = item->refname;
 	char *to_free = NULL;
 
-	if (item->ignore)
-		return;
-
 	switch (item->kind) {
 	case FILTER_REFS_BRANCHES:
-		if (!filter->detached && !strcmp(item->refname, head))
+		skip_prefix(desc, "refs/heads/", &desc);
+		if (!filter->detached && !strcmp(desc, head))
 			current = 1;
 		else
 			color = BRANCH_COLOR_LOCAL;
 		break;
 	case FILTER_REFS_REMOTES:
+		skip_prefix(desc, "refs/remotes/", &desc);
 		color = BRANCH_COLOR_REMOTE;
 		prefix = remote_prefix;
 		break;
@@ -554,11 +434,13 @@ static void print_ref_item(struct ref_array_item *item, int maxwidth,
 		strbuf_addf(&out, "%c %s%s%s", c, branch_get_color(color),
 			    name.buf, branch_get_color(BRANCH_COLOR_RESET));
 
-	if (item->symref)
-		strbuf_addf(&out, " -> %s", item->symref);
+	if (item->symref) {
+		skip_prefix(item->symref, "refs/remotes/", &desc);
+		strbuf_addf(&out, " -> %s", desc);
+	}
 	else if (filter->verbose)
 		/* " f7c0c00 [ahead 58, behind 197] vcs-svn: drop obj_pool.h" */
-		add_verbose_info(&out, item, filter);
+		add_verbose_info(&out, item, filter, desc);
 	if (column_active(colopts)) {
 		assert(!filter->verbose && "--column and --verbose are incompatible");
 		string_list_append(&output, out.buf);
@@ -575,11 +457,13 @@ static int calc_maxwidth(struct ref_array *refs, int remote_bonus)
 	int i, max = 0;
 	for (i = 0; i < refs->nr; i++) {
 		struct ref_array_item *it = refs->items[i];
+		const char *desc = it->refname;
 		int w;
 
-		if (it->ignore)
-			continue;
-		w = utf8_strwidth(it->refname);
+		skip_prefix(it->refname, "refs/heads/", &desc);
+		skip_prefix(it->refname, "refs/remotes/", &desc);
+		w = utf8_strwidth(desc);
+
 		if (it->kind == FILTER_REFS_REMOTES)
 			w += remote_bonus;
 		if (w > max)
@@ -588,14 +472,12 @@ static int calc_maxwidth(struct ref_array *refs, int remote_bonus)
 	return max;
 }
 
-static void print_ref_list(struct ref_filter *filter)
+static void print_ref_list(struct ref_filter *filter, struct ref_sorting *sorting)
 {
 	int i;
 	struct ref_array array;
-	struct ref_filter_cbdata data;
 	int maxwidth = 0;
 	const char *remote_prefix = "";
-	struct rev_info revs;
 
 	/*
 	 * If we are listing more than just remote branches,
@@ -606,54 +488,26 @@ static void print_ref_list(struct ref_filter *filter)
 		remote_prefix = "remotes/";
 
 	memset(&array, 0, sizeof(array));
-	if (filter->merge != REF_FILTER_MERGED_NONE)
-		init_revisions(&revs, NULL);
-
-	data.array = &array;
-	data.filter = filter;
-	array.revs = &revs;
-
-	/*
-	 * First we obtain all regular branch refs and if the HEAD is
-	 * detached then we insert that ref to the end of the ref_fist
-	 * so that it can be printed and removed first.
-	 */
-	for_each_rawref(append_ref, &data);
-	if (filter->detached)
-		head_ref(append_ref, &data);
-	/*
-	 * The following implementation is currently duplicated in ref-filter. It
-	 * will eventually be removed when we port branch.c to use ref-filter APIs.
-	 */
-	if (filter->merge != REF_FILTER_MERGED_NONE) {
-		filter->merge_commit->object.flags |= UNINTERESTING;
-		add_pending_object(&revs, &filter->merge_commit->object, "");
-		revs.limited = 1;
-
-		if (prepare_revision_walk(&revs))
-			die(_("revision walk setup failed"));
-
-		for (i = 0; i < array.nr; i++) {
-			struct ref_array_item *item = array.items[i];
-			struct commit *commit = item->commit;
-			int is_merged = !!(commit->object.flags & UNINTERESTING);
-			item->ignore = is_merged != (filter->merge == REF_FILTER_MERGED_INCLUDE);
-		}
 
-		for (i = 0; i < array.nr; i++) {
-			struct ref_array_item *item = array.items[i];
-			clear_commit_marks(item->commit, ALL_REV_FLAGS);
-		}
-		clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
-	}
+	verify_ref_format("%(refname)%(symref)");
+	filter_refs(&array, filter, filter->kind | FILTER_REFS_INCLUDE_BROKEN);
 
 	if (filter->verbose)
 		maxwidth = calc_maxwidth(&array, strlen(remote_prefix));
 
-	qsort(array.items, array.nr, sizeof(struct ref_array_item *), ref_cmp);
+	/*
+	 * If no sorting parameter is given then we default to sorting
+	 * by 'refname'. This would give us an alphabetically sorted
+	 * array with the 'HEAD' ref at the beginning followed by
+	 * local branches 'refs/heads/...' and finally remote-tacking
+	 * branches 'refs/remotes/...'.
+	 */
+	if (!sorting)
+		sorting = ref_default_sorting();
+	ref_array_sort(sorting, &array);
 
 	for (i = 0; i < array.nr; i++)
-		print_ref_item(array.items[i], maxwidth, filter, remote_prefix);
+		format_and_print_ref_item(array.items[i], maxwidth, filter, remote_prefix);
 
 	ref_array_clear(&array);
 }
@@ -755,6 +609,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 	const char *new_upstream = NULL;
 	enum branch_track track;
 	struct ref_filter filter;
+	static struct ref_sorting *sorting = NULL, **sorting_tail = &sorting;
 
 	struct option options[] = {
 		OPT_GROUP(N_("Generic options")),
@@ -789,6 +644,8 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		OPT_MERGED(&filter, N_("print only branches that are merged")),
 		OPT_NO_MERGED(&filter, N_("print only branches that are not merged")),
 		OPT_COLUMN(0, "column", &colopts, N_("list branches in columns")),
+		OPT_CALLBACK(0 , "sort", sorting_tail, N_("key"),
+			     N_("field name to sort on"), &parse_opt_ref_sorting),
 		OPT_END(),
 	};
 
@@ -847,7 +704,7 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		if ((filter.kind & FILTER_REFS_BRANCHES) && filter.detached)
 			filter.kind |= FILTER_REFS_DETACHED_HEAD;
 		filter.name_patterns = argv;
-		print_ref_list(&filter);
+		print_ref_list(&filter, sorting);
 		print_columns(&output, colopts, NULL);
 		string_list_clear(&output, 0);
 		return 0;
diff --git a/ref-filter.c b/ref-filter.c
index fd839ac4b..dbd8fcec2 100644
--- a/ref-filter.c
+++ b/ref-filter.c
@@ -1331,7 +1331,7 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
 	 * obtain the commit using the 'oid' available and discard all
 	 * non-commits early. The actual filtering is done later.
 	 */
-	if (filter->merge_commit || filter->with_commit) {
+	if (filter->merge_commit || filter->with_commit || filter->verbose) {
 		commit = lookup_commit_reference_gently(oid->hash, 1);
 		if (!commit)
 			return 0;
diff --git a/ref-filter.h b/ref-filter.h
index fadebc5da..14d435e2c 100644
--- a/ref-filter.h
+++ b/ref-filter.h
@@ -36,7 +36,6 @@ struct ref_array_item {
 	unsigned char objectname[20];
 	int flag;
 	unsigned int kind;
-	int ignore : 1; /* To be removed in the next patch */
 	const char *symref;
 	struct commit *commit;
 	struct atom_value *value;
diff --git a/t/t1430-bad-ref-name.sh b/t/t1430-bad-ref-name.sh
index 16d0b8bd1..c465abe8e 100755
--- a/t/t1430-bad-ref-name.sh
+++ b/t/t1430-bad-ref-name.sh
@@ -38,18 +38,20 @@ test_expect_success 'fast-import: fail on invalid branch name "bad[branch]name"'
 	test_must_fail git fast-import <input
 '
 
-test_expect_success 'git branch shows badly named ref' '
+test_expect_success 'git branch shows badly named ref as warning' '
 	cp .git/refs/heads/master .git/refs/heads/broken...ref &&
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
-	git branch >output &&
-	grep -e "broken\.\.\.ref" output
+	git branch >output 2>error &&
+	grep -e "broken\.\.\.ref" error &&
+	! grep -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'branch -d can delete badly named ref' '
 	cp .git/refs/heads/master .git/refs/heads/broken...ref &&
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
 	git branch -d broken...ref &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
@@ -57,7 +59,8 @@ test_expect_success 'branch -D can delete badly named ref' '
 	cp .git/refs/heads/master .git/refs/heads/broken...ref &&
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
 	git branch -D broken...ref &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
@@ -85,7 +88,8 @@ test_expect_success 'branch -D cannot delete absolute path' '
 test_expect_success 'git branch cannot create a badly named ref' '
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
 	test_must_fail git branch broken...ref &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
@@ -95,7 +99,8 @@ test_expect_success 'branch -m cannot rename to a bad ref name' '
 	git branch goodref &&
 	test_must_fail git branch -m goodref broken...ref &&
 	test_cmp_rev master goodref &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
@@ -104,14 +109,16 @@ test_expect_failure 'branch -m can rename from a bad ref name' '
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
 	git branch -m broken...ref renamed &&
 	test_cmp_rev master renamed &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
 test_expect_success 'push cannot create a badly named ref' '
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
 	test_must_fail git push "file://$(pwd)" HEAD:refs/heads/broken...ref &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
@@ -131,7 +138,8 @@ test_expect_failure 'push --mirror can delete badly named ref' '
 		cp .git/refs/heads/master .git/refs/heads/broken...ref
 	) &&
 	git -C src push --mirror "file://$top/dest" &&
-	git -C dest branch >output &&
+	git -C dest branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
@@ -159,7 +167,8 @@ test_expect_success 'update-ref -d can delete broken name' '
 	cp .git/refs/heads/master .git/refs/heads/broken...ref &&
 	test_when_finished "rm -f .git/refs/heads/broken...ref" &&
 	git update-ref -d refs/heads/broken...ref &&
-	git branch >output &&
+	git branch >output 2>error &&
+	! grep -e "broken\.\.\.ref" error &&
 	! grep -e "broken\.\.\.ref" output
 '
 
diff --git a/t/t3203-branch-output.sh b/t/t3203-branch-output.sh
index f51d0f3ca..a427163c4 100755
--- a/t/t3203-branch-output.sh
+++ b/t/t3203-branch-output.sh
@@ -143,4 +143,15 @@ EOF
 	test_i18ncmp expect actual
 '
 
+test_expect_success 'git branch `--sort` option' '
+	cat >expect <<-\EOF &&
+	  branch-two
+	* (HEAD detached from fromtag)
+	  branch-one
+	  master
+	EOF
+	git branch --sort=objectsize >actual &&
+	test_i18ncmp expect actual
+'
+
 test_done