Merge branch 'kn/for-each-tag-branch'

Some features from "git tag -l" and "git branch -l" have been made
available to "git for-each-ref" so that eventually the unified
implementation can be shared across all three, in a follow-up
series or two.

* kn/for-each-tag-branch:
  for-each-ref: add '--contains' option
  ref-filter: implement '--contains' option
  parse-options.h: add macros for '--contains' option
  parse-option: rename parse_opt_with_commit()
  for-each-ref: add '--merged' and '--no-merged' options
  ref-filter: implement '--merged' and '--no-merged' options
  ref-filter: add parse_opt_merge_filter()
  for-each-ref: add '--points-at' option
  ref-filter: implement '--points-at' option
  tag: libify parse_opt_points_at()
  t6302: for-each-ref tests for ref-filter APIs

Documentation/git-for-each-ref.txt

@@ -10,6 +10,8 @@ SYNOPSIS
 [verse]
 'git for-each-ref' [--count=<count>] [--shell|--perl|--python|--tcl]
 		   [(--sort=<key>)...] [--format=<format>] [<pattern>...]
+		   [--points-at <object>] [(--merged | --no-merged) [<object>]]
+		   [--contains [<object>]]
 
 DESCRIPTION
 -----------
@@ -62,6 +64,20 @@ OPTIONS
 	the specified host language.  This is meant to produce
 	a scriptlet that can directly be `eval`ed.
 
+--points-at <object>::
+	Only list refs which points at the given object.
+
+--merged [<object>]::
+	Only list refs whose tips are reachable from the
+	specified commit (HEAD if not specified).
+
+--no-merged [<object>]::
+	Only list refs whose tips are not reachable from the
+	specified commit (HEAD if not specified).
+
+--contains [<object>]::
+	Only list tags which contain the specified commit (HEAD if not
+	specified).
 
 FIELD NAMES
 -----------

builtin/branch.c

@@ -636,6 +636,10 @@ static int print_ref_list(int kinds, int detached, int verbose, int abbrev, stru
 	cb.pattern = pattern;
 	cb.ret = 0;
 	for_each_rawref(append_ref, &cb);
+	/*
+	 * 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 (merge_filter != NO_FILTER) {
 		struct commit *filter;
 		filter = lookup_commit_reference_gently(merge_filter_ref, 0);
@@ -746,6 +750,10 @@ static void rename_branch(const char *oldname, const char *newname, int force)
 	strbuf_release(&newsection);
 }
 
+/*
+ * This function is duplicated in ref-filter. It will eventually be removed
+ * when we port branch.c to use ref-filter APIs.
+ */
 static int opt_parse_merge_filter(const struct option *opt, const char *arg, int unset)
 {
 	merge_filter = ((opt->long_name[0] == 'n')
@@ -821,18 +829,8 @@ int cmd_branch(int argc, const char **argv, const char *prefix)
 		OPT__COLOR(&branch_use_color, N_("use colored output")),
 		OPT_SET_INT('r', "remotes",     &kinds, N_("act on remote-tracking branches"),
 			REF_REMOTE_BRANCH),
-		{
-			OPTION_CALLBACK, 0, "contains", &with_commit, N_("commit"),
-			N_("print only branches that contain the commit"),
-			PARSE_OPT_LASTARG_DEFAULT,
-			parse_opt_with_commit, (intptr_t)"HEAD",
-		},
-		{
-			OPTION_CALLBACK, 0, "with", &with_commit, N_("commit"),
-			N_("print only branches that contain the commit"),
-			PARSE_OPT_HIDDEN | PARSE_OPT_LASTARG_DEFAULT,
-			parse_opt_with_commit, (intptr_t) "HEAD",
-		},
+		OPT_CONTAINS(&with_commit, N_("print only branches that contain the commit")),
+		OPT_WITH(&with_commit, N_("print only branches that contain the commit")),
 		OPT__ABBREV(&abbrev),
 
 		OPT_GROUP(N_("Specific git-branch actions:")),

builtin/for-each-ref.c

@@ -7,6 +7,9 @@
 
 static char const * const for_each_ref_usage[] = {
 	N_("git for-each-ref [<options>] [<pattern>]"),
+	N_("git for-each-ref [--points-at <object>]"),
+	N_("git for-each-ref [(--merged | --no-merged) [<object>]]"),
+	N_("git for-each-ref [--contains [<object>]]"),
 	NULL
 };
 
@@ -34,9 +37,18 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 		OPT_STRING(  0 , "format", &format, N_("format"), N_("format to use for the output")),
 		OPT_CALLBACK(0 , "sort", sorting_tail, N_("key"),
 			    N_("field name to sort on"), &parse_opt_ref_sorting),
+		OPT_CALLBACK(0, "points-at", &filter.points_at,
+			     N_("object"), N_("print only refs which points at the given object"),
+			     parse_opt_object_name),
+		OPT_MERGED(&filter, N_("print only refs that are merged")),
+		OPT_NO_MERGED(&filter, N_("print only refs that are not merged")),
+		OPT_CONTAINS(&filter.with_commit, N_("print only refs which contain the commit")),
 		OPT_END(),
 	};
 
+	memset(&array, 0, sizeof(array));
+	memset(&filter, 0, sizeof(filter));
+
 	parse_options(argc, argv, prefix, opts, for_each_ref_usage, 0);
 	if (maxcount < 0) {
 		error("invalid --count argument: `%d'", maxcount);
@@ -55,8 +67,6 @@ int cmd_for_each_ref(int argc, const char **argv, const char *prefix)
 	/* for warn_ambiguous_refs */
 	git_config(git_default_config, NULL);
 
-	memset(&array, 0, sizeof(array));
-	memset(&filter, 0, sizeof(filter));
 	filter.name_patterns = argv;
 	filter_refs(&array, &filter, FILTER_REFS_ALL | FILTER_REFS_INCLUDE_BROKEN);
 	ref_array_sort(sorting, &array);

builtin/tag.c

@@ -56,6 +56,10 @@ static int match_pattern(const char **patterns, const char *ref)
 	return 0;
 }
 
+/*
+ * This is currently duplicated in ref-filter.c, and will eventually be
+ * removed as we port tag.c to use the ref-filter APIs.
+ */
 static const unsigned char *match_points_at(const char *refname,
 					    const unsigned char *sha1)
 {
@@ -82,6 +86,11 @@ static int in_commit_list(const struct commit_list *want, struct commit *c)
 	return 0;
 }
 
+/*
+ * The entire code segment for supporting the --contains option has been
+ * copied over to ref-filter.{c,h}. This will be deleted evetually when
+ * we port tag.c to use ref-filter APIs.
+ */
 enum contains_result {
 	CONTAINS_UNKNOWN = -1,
 	CONTAINS_NO = 0,
@@ -546,23 +555,6 @@ static int strbuf_check_tag_ref(struct strbuf *sb, const char *name)
 	return check_refname_format(sb->buf, 0);
 }
 
-static int parse_opt_points_at(const struct option *opt __attribute__((unused)),
-			const char *arg, int unset)
-{
-	unsigned char sha1[20];
-
-	if (unset) {
-		sha1_array_clear(&points_at);
-		return 0;
-	}
-	if (!arg)
-		return error(_("switch 'points-at' requires an object"));
-	if (get_sha1(arg, sha1))
-		return error(_("malformed object name '%s'"), arg);
-	sha1_array_append(&points_at, sha1);
-	return 0;
-}
-
 static int parse_opt_sort(const struct option *opt, const char *arg, int unset)
 {
 	int *sort = opt->value;
@@ -610,25 +602,15 @@ int cmd_tag(int argc, const char **argv, const char *prefix)
 
 		OPT_GROUP(N_("Tag listing options")),
 		OPT_COLUMN(0, "column", &colopts, N_("show tag list in columns")),
+		OPT_CONTAINS(&with_commit, N_("print only tags that contain the commit")),
+		OPT_WITH(&with_commit, N_("print only tags that contain the commit")),
 		{
 			OPTION_CALLBACK, 0, "sort", &tag_sort, N_("type"), N_("sort tags"),
 			PARSE_OPT_NONEG, parse_opt_sort
 		},
 		{
-			OPTION_CALLBACK, 0, "contains", &with_commit, N_("commit"),
-			N_("print only tags that contain the commit"),
-			PARSE_OPT_LASTARG_DEFAULT,
-			parse_opt_with_commit, (intptr_t)"HEAD",
-		},
-		{
-			OPTION_CALLBACK, 0, "with", &with_commit, N_("commit"),
-			N_("print only tags that contain the commit"),
-			PARSE_OPT_HIDDEN | PARSE_OPT_LASTARG_DEFAULT,
-			parse_opt_with_commit, (intptr_t)"HEAD",
-		},
-		{
-			OPTION_CALLBACK, 0, "points-at", NULL, N_("object"),
-			N_("print only tags of the object"), 0, parse_opt_points_at
+			OPTION_CALLBACK, 0, "points-at", &points_at, N_("object"),
+			N_("print only tags of the object"), 0, parse_opt_object_name
 		},
 		OPT_END()
 	};

parse-options-cb.c

@@ -5,6 +5,7 @@
 #include "color.h"
 #include "string-list.h"
 #include "argv-array.h"
+#include "sha1-array.h"
 
 /*----- some often used options -----*/
 
@@ -77,7 +78,7 @@ int parse_opt_verbosity_cb(const struct option *opt, const char *arg,
 	return 0;
 }
 
-int parse_opt_with_commit(const struct option *opt, const char *arg, int unset)
+int parse_opt_commits(const struct option *opt, const char *arg, int unset)
 {
 	unsigned char sha1[20];
 	struct commit *commit;
@@ -93,6 +94,22 @@ int parse_opt_with_commit(const struct option *opt, const char *arg, int unset)
 	return 0;
 }
 
+int parse_opt_object_name(const struct option *opt, const char *arg, int unset)
+{
+	unsigned char sha1[20];
+
+	if (unset) {
+		sha1_array_clear(opt->value);
+		return 0;
+	}
+	if (!arg)
+		return -1;
+	if (get_sha1(arg, sha1))
+		return error(_("malformed object name '%s'"), arg);
+	sha1_array_append(opt->value, sha1);
+	return 0;
+}
+
 int parse_opt_tertiary(const struct option *opt, const char *arg, int unset)
 {
 	int *target = opt->value;

parse-options.h

@@ -223,7 +223,8 @@ extern int parse_opt_approxidate_cb(const struct option *, const char *, int);
 extern int parse_opt_expiry_date_cb(const struct option *, const char *, int);
 extern int parse_opt_color_flag_cb(const struct option *, const char *, int);
 extern int parse_opt_verbosity_cb(const struct option *, const char *, int);
-extern int parse_opt_with_commit(const struct option *, const char *, int);
+extern int parse_opt_object_name(const struct option *, const char *, int);
+extern int parse_opt_commits(const struct option *, const char *, int);
 extern int parse_opt_tertiary(const struct option *, const char *, int);
 extern int parse_opt_string_list(const struct option *, const char *, int);
 extern int parse_opt_noop_cb(const struct option *, const char *, int);
@@ -251,5 +252,12 @@ extern int parse_opt_passthru_argv(const struct option *, const char *, int);
 	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), (f), parse_opt_passthru }
 #define OPT_PASSTHRU_ARGV(s, l, v, a, h, f) \
 	{ OPTION_CALLBACK, (s), (l), (v), (a), (h), (f), parse_opt_passthru_argv }
+#define _OPT_CONTAINS_OR_WITH(name, variable, help, flag) \
+	{ OPTION_CALLBACK, 0, name, (variable), N_("commit"), (help), \
+	  PARSE_OPT_LASTARG_DEFAULT | flag, \
+	  parse_opt_commits, (intptr_t) "HEAD" \
+	}
+#define OPT_CONTAINS(v, h) _OPT_CONTAINS_OR_WITH("contains", v, h, 0)
+#define OPT_WITH(v, h) _OPT_CONTAINS_OR_WITH("with", v, h, PARSE_OPT_HIDDEN)
 
 #endif

ref-filter.c

@@ -9,6 +9,7 @@
 #include "tag.h"
 #include "quote.h"
 #include "ref-filter.h"
+#include "revision.h"
 
 typedef enum { FIELD_STR, FIELD_ULONG, FIELD_TIME } cmp_type;
 
@@ -817,6 +818,114 @@ static void get_ref_atom_value(struct ref_array_item *ref, int atom, struct atom
 	*v = &ref->value[atom];
 }
 
+enum contains_result {
+	CONTAINS_UNKNOWN = -1,
+	CONTAINS_NO = 0,
+	CONTAINS_YES = 1
+};
+
+/*
+ * Mimicking the real stack, this stack lives on the heap, avoiding stack
+ * overflows.
+ *
+ * At each recursion step, the stack items points to the commits whose
+ * ancestors are to be inspected.
+ */
+struct contains_stack {
+	int nr, alloc;
+	struct contains_stack_entry {
+		struct commit *commit;
+		struct commit_list *parents;
+	} *contains_stack;
+};
+
+static int in_commit_list(const struct commit_list *want, struct commit *c)
+{
+	for (; want; want = want->next)
+		if (!hashcmp(want->item->object.sha1, c->object.sha1))
+			return 1;
+	return 0;
+}
+
+/*
+ * Test whether the candidate or one of its parents is contained in the list.
+ * Do not recurse to find out, though, but return -1 if inconclusive.
+ */
+static enum contains_result contains_test(struct commit *candidate,
+			    const struct commit_list *want)
+{
+	/* was it previously marked as containing a want commit? */
+	if (candidate->object.flags & TMP_MARK)
+		return 1;
+	/* or marked as not possibly containing a want commit? */
+	if (candidate->object.flags & UNINTERESTING)
+		return 0;
+	/* or are we it? */
+	if (in_commit_list(want, candidate)) {
+		candidate->object.flags |= TMP_MARK;
+		return 1;
+	}
+
+	if (parse_commit(candidate) < 0)
+		return 0;
+
+	return -1;
+}
+
+static void push_to_contains_stack(struct commit *candidate, struct contains_stack *contains_stack)
+{
+	ALLOC_GROW(contains_stack->contains_stack, contains_stack->nr + 1, contains_stack->alloc);
+	contains_stack->contains_stack[contains_stack->nr].commit = candidate;
+	contains_stack->contains_stack[contains_stack->nr++].parents = candidate->parents;
+}
+
+static enum contains_result contains_tag_algo(struct commit *candidate,
+		const struct commit_list *want)
+{
+	struct contains_stack contains_stack = { 0, 0, NULL };
+	int result = contains_test(candidate, want);
+
+	if (result != CONTAINS_UNKNOWN)
+		return result;
+
+	push_to_contains_stack(candidate, &contains_stack);
+	while (contains_stack.nr) {
+		struct contains_stack_entry *entry = &contains_stack.contains_stack[contains_stack.nr - 1];
+		struct commit *commit = entry->commit;
+		struct commit_list *parents = entry->parents;
+
+		if (!parents) {
+			commit->object.flags |= UNINTERESTING;
+			contains_stack.nr--;
+		}
+		/*
+		 * If we just popped the stack, parents->item has been marked,
+		 * therefore contains_test will return a meaningful 0 or 1.
+		 */
+		else switch (contains_test(parents->item, want)) {
+		case CONTAINS_YES:
+			commit->object.flags |= TMP_MARK;
+			contains_stack.nr--;
+			break;
+		case CONTAINS_NO:
+			entry->parents = parents->next;
+			break;
+		case CONTAINS_UNKNOWN:
+			push_to_contains_stack(parents->item, &contains_stack);
+			break;
+		}
+	}
+	free(contains_stack.contains_stack);
+	return contains_test(candidate, want);
+}
+
+static int commit_contains(struct ref_filter *filter, struct commit *commit)
+{
+	if (filter->with_commit_tag_algo)
+		return contains_tag_algo(commit, filter->with_commit);
+	return is_descendant_of(commit, filter->with_commit);
+}
+
 /*
  * Return 1 if the refname matches one of the patterns, otherwise 0.
  * A pattern can be path prefix (e.g. a refname "refs/heads/master"
@@ -842,6 +951,38 @@ static int match_name_as_path(const char **pattern, const char *refname)
 	return 0;
 }
 
+/*
+ * Given a ref (sha1, refname), check if the ref belongs to the array
+ * of sha1s. If the given ref is a tag, check if the given tag points
+ * at one of the sha1s in the given sha1 array.
+ * the given sha1_array.
+ * NEEDSWORK:
+ * 1. Only a single level of inderection is obtained, we might want to
+ * change this to account for multiple levels (e.g. annotated tags
+ * pointing to annotated tags pointing to a commit.)
+ * 2. As the refs are cached we might know what refname peels to without
+ * the need to parse the object via parse_object(). peel_ref() might be a
+ * more efficient alternative to obtain the pointee.
+ */
+static const unsigned char *match_points_at(struct sha1_array *points_at,
+					    const unsigned char *sha1,
+					    const char *refname)
+{
+	const unsigned char *tagged_sha1 = NULL;
+	struct object *obj;
+
+	if (sha1_array_lookup(points_at, sha1) >= 0)
+		return sha1;
+	obj = parse_object(sha1);
+	if (!obj)
+		die(_("malformed object at '%s'"), refname);
+	if (obj->type == OBJ_TAG)
+		tagged_sha1 = ((struct tag *)obj)->tagged->sha1;
+	if (tagged_sha1 && sha1_array_lookup(points_at, tagged_sha1) >= 0)
+		return tagged_sha1;
+	return NULL;
+}
+
 /* Allocate space for a new ref_array_item and copy the objectname and flag to it */
 static struct ref_array_item *new_ref_array_item(const char *refname,
 						 const unsigned char *objectname,
@@ -866,6 +1007,7 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
 	struct ref_filter_cbdata *ref_cbdata = cb_data;
 	struct ref_filter *filter = ref_cbdata->filter;
 	struct ref_array_item *ref;
+	struct commit *commit = NULL;
 
 	if (flag & REF_BAD_NAME) {
 		warning("ignoring ref with broken name %s", refname);
@@ -880,12 +1022,31 @@ static int ref_filter_handler(const char *refname, const struct object_id *oid,
 	if (*filter->name_patterns && !match_name_as_path(filter->name_patterns, refname))
 		return 0;
 
+	if (filter->points_at.nr && !match_points_at(&filter->points_at, oid->hash, refname))
+		return 0;
+
+	/*
+	 * A merge filter is applied on refs pointing to commits. Hence
+	 * 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) {
+		commit = lookup_commit_reference_gently(oid->hash, 1);
+		if (!commit)
+			return 0;
+		/* We perform the filtering for the '--contains' option */
+		if (filter->with_commit &&
+		    !commit_contains(filter, commit))
+			return 0;
+	}
+
 	/*
 	 * We do not open the object yet; sort may only need refname
 	 * to do its job and the resulting list may yet to be pruned
 	 * by maxcount logic.
 	 */
 	ref = new_ref_array_item(refname, oid->hash, flag);
+	ref->commit = commit;
 
 	REALLOC_ARRAY(ref_cbdata->array->items, ref_cbdata->array->nr + 1);
 	ref_cbdata->array->items[ref_cbdata->array->nr++] = ref;
@@ -911,6 +1072,50 @@ void ref_array_clear(struct ref_array *array)
 	array->nr = array->alloc = 0;
 }
 
+static void do_merge_filter(struct ref_filter_cbdata *ref_cbdata)
+{
+	struct rev_info revs;
+	int i, old_nr;
+	struct ref_filter *filter = ref_cbdata->filter;
+	struct ref_array *array = ref_cbdata->array;
+	struct commit **to_clear = xcalloc(sizeof(struct commit *), array->nr);
+
+	init_revisions(&revs, NULL);
+
+	for (i = 0; i < array->nr; i++) {
+		struct ref_array_item *item = array->items[i];
+		add_pending_object(&revs, &item->commit->object, item->refname);
+		to_clear[i] = item->commit;
+	}
+
+	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"));
+
+	old_nr = array->nr;
+	array->nr = 0;
+
+	for (i = 0; i < old_nr; i++) {
+		struct ref_array_item *item = array->items[i];
+		struct commit *commit = item->commit;
+
+		int is_merged = !!(commit->object.flags & UNINTERESTING);
+
+		if (is_merged == (filter->merge == REF_FILTER_MERGED_INCLUDE))
+			array->items[array->nr++] = array->items[i];
+		else
+			free_array_item(item);
+	}
+
+	for (i = 0; i < old_nr; i++)
+		clear_commit_marks(to_clear[i], ALL_REV_FLAGS);
+	clear_commit_marks(filter->merge_commit, ALL_REV_FLAGS);
+	free(to_clear);
+}
+
 /*
  * API for filtering a set of refs. Based on the type of refs the user
  * has requested, we iterate through those refs and apply filters
@@ -920,17 +1125,24 @@ void ref_array_clear(struct ref_array *array)
 int filter_refs(struct ref_array *array, struct ref_filter *filter, unsigned int type)
 {
 	struct ref_filter_cbdata ref_cbdata;
+	int ret = 0;
 
 	ref_cbdata.array = array;
 	ref_cbdata.filter = filter;
 
+	/*  Simple per-ref filtering */
 	if (type & (FILTER_REFS_ALL | FILTER_REFS_INCLUDE_BROKEN))
-		return for_each_rawref(ref_filter_handler, &ref_cbdata);
+		ret = for_each_rawref(ref_filter_handler, &ref_cbdata);
 	else if (type & FILTER_REFS_ALL)
-		return for_each_ref(ref_filter_handler, &ref_cbdata);
-	else
+		ret = for_each_ref(ref_filter_handler, &ref_cbdata);
+	else if (type)
 		die("filter_refs: invalid type");
-	return 0;
+
+	/*  Filters that need revision walking */
+	if (filter->merge_commit)
+		do_merge_filter(&ref_cbdata);
+
+	return ret;
 }
 
 static int cmp_ref_sorting(struct ref_sorting *s, struct ref_array_item *a, struct ref_array_item *b)
@@ -1104,3 +1316,22 @@ int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset)
 	s->atom = parse_ref_filter_atom(arg, arg+len);
 	return 0;
 }
+
+int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset)
+{
+	struct ref_filter *rf = opt->value;
+	unsigned char sha1[20];
+
+	rf->merge = starts_with(opt->long_name, "no")
+		? REF_FILTER_MERGED_OMIT
+		: REF_FILTER_MERGED_INCLUDE;
+
+	if (get_sha1(arg, sha1))
+		die(_("malformed object name %s"), arg);
+
+	rf->merge_commit = lookup_commit_reference_gently(sha1, 0);
+	if (!rf->merge_commit)
+		return opterror(opt, "must point to a commit", 0);
+
+	return 0;
+}

ref-filter.h

@@ -31,6 +31,7 @@ struct ref_array_item {
 	unsigned char objectname[20];
 	int flag;
 	const char *symref;
+	struct commit *commit;
 	struct atom_value *value;
 	char refname[FLEX_ARRAY];
 };
@@ -42,6 +43,17 @@ struct ref_array {
 
 struct ref_filter {
 	const char **name_patterns;
+	struct sha1_array points_at;
+	struct commit_list *with_commit;
+
+	enum {
+		REF_FILTER_MERGED_NONE = 0,
+		REF_FILTER_MERGED_INCLUDE,
+		REF_FILTER_MERGED_OMIT
+	} merge;
+	struct commit *merge_commit;
+
+	unsigned int with_commit_tag_algo : 1;
 };
 
 struct ref_filter_cbdata {
@@ -49,6 +61,15 @@ struct ref_filter_cbdata {
 	struct ref_filter *filter;
 };
 
+/*  Macros for checking --merged and --no-merged options */
+#define _OPT_MERGED_NO_MERGED(option, filter, h) \
+	{ OPTION_CALLBACK, 0, option, (filter), N_("commit"), (h), \
+	  PARSE_OPT_LASTARG_DEFAULT | PARSE_OPT_NONEG, \
+	  parse_opt_merge_filter, (intptr_t) "HEAD" \
+	}
+#define OPT_MERGED(f, h) _OPT_MERGED_NO_MERGED("merged", f, h)
+#define OPT_NO_MERGED(f, h) _OPT_MERGED_NO_MERGED("no-merged", f, h)
+
 /*
  * API for filtering a set of refs. Based on the type of refs the user
  * has requested, we iterate through those refs and apply filters
@@ -70,5 +91,7 @@ void show_ref_array_item(struct ref_array_item *info, const char *format, int qu
 int parse_opt_ref_sorting(const struct option *opt, const char *arg, int unset);
 /*  Default sort option based on refname */
 struct ref_sorting *ref_default_sorting(void);
+/*  Function to parse --merged and --no-merged options */
+int parse_opt_merge_filter(const struct option *opt, const char *arg, int unset);
 
 #endif /*  REF_FILTER_H  */

t/t6302-for-each-ref-filter.sh

@@ -0,0 +1,84 @@
+#!/bin/sh
+
+test_description='test for-each-refs usage of ref-filter APIs'
+
+. ./test-lib.sh
+. "$TEST_DIRECTORY"/lib-gpg.sh
+
+if ! test_have_prereq GPG
+then
+	skip_all="skipping for-each-ref tests, GPG not available"
+	test_done
+fi
+
+test_expect_success 'setup some history and refs' '
+	test_commit one &&
+	test_commit two &&
+	test_commit three &&
+	git checkout -b side &&
+	test_commit four &&
+	git tag -s -m "A signed tag message" signed-tag &&
+	git tag -s -m "Annonated doubly" double-tag signed-tag &&
+	git checkout master &&
+	git update-ref refs/odd/spot master
+'
+
+test_expect_success 'filtering with --points-at' '
+	cat >expect <<-\EOF &&
+	refs/heads/master
+	refs/odd/spot
+	refs/tags/three
+	EOF
+	git for-each-ref --format="%(refname)" --points-at=master >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'check signed tags with --points-at' '
+	sed -e "s/Z$//" >expect <<-\EOF &&
+	refs/heads/side Z
+	refs/tags/four Z
+	refs/tags/signed-tag four
+	EOF
+	git for-each-ref --format="%(refname) %(*subject)" --points-at=side >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'filtering with --merged' '
+	cat >expect <<-\EOF &&
+	refs/heads/master
+	refs/odd/spot
+	refs/tags/one
+	refs/tags/three
+	refs/tags/two
+	EOF
+	git for-each-ref --format="%(refname)" --merged=master >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'filtering with --no-merged' '
+	cat >expect <<-\EOF &&
+	refs/heads/side
+	refs/tags/double-tag
+	refs/tags/four
+	refs/tags/signed-tag
+	EOF
+	git for-each-ref --format="%(refname)" --no-merged=master >actual &&
+	test_cmp expect actual
+'
+
+test_expect_success 'filtering with --contains' '
+	cat >expect <<-\EOF &&
+	refs/heads/master
+	refs/heads/side
+	refs/odd/spot
+	refs/tags/double-tag
+	refs/tags/four
+	refs/tags/signed-tag
+	refs/tags/three
+	refs/tags/two
+	EOF
+	git for-each-ref --format="%(refname)" --contains=two >actual &&
+	test_cmp expect actual
+'
+
+test_done