[1/2] Lib-ify fmt-merge-msg
diff mbox series

Message ID d989ab8b088742378cb9a7deb8412b8fe10e38b7.1584786523.git.liu.denton@gmail.com
State New
Headers show
Series
  • Lib-ify functions in builtin.h
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Commit Message

Denton Liu March 21, 2020, 10:29 a.m. UTC
In builtin.h, there exists the distinctly lib-ish function
fmt_merge_msg(). Extract this function into fmt-merge-msg.c so that
related definitions can exist clearly in their own header file.

While we're at it, clean up #includes that are unused.

This patch is best viewed with --color-moved.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
---
 Makefile                |   1 +
 builtin.h               |  11 -
 builtin/fmt-merge-msg.c | 655 +---------------------------------------
 fmt-merge-msg.c         | 653 +++++++++++++++++++++++++++++++++++++++
 fmt-merge-msg.h         |  13 +
 5 files changed, 668 insertions(+), 665 deletions(-)
 create mode 100644 fmt-merge-msg.c

Patch
diff mbox series

diff --git a/Makefile b/Makefile
index 9804a0758b..04e3cc179e 100644
--- a/Makefile
+++ b/Makefile
@@ -886,6 +886,7 @@  LIB_OBJS += ewah/ewah_rlw.o
 LIB_OBJS += exec-cmd.o
 LIB_OBJS += fetch-negotiator.o
 LIB_OBJS += fetch-pack.o
+LIB_OBJS += fmt-merge-msg.o
 LIB_OBJS += fsck.o
 LIB_OBJS += fsmonitor.o
 LIB_OBJS += gettext.o
diff --git a/builtin.h b/builtin.h
index 2b25a80cde..6101d98661 100644
--- a/builtin.h
+++ b/builtin.h
@@ -94,8 +94,6 @@ 
  * command.
  */
 
-#define DEFAULT_MERGE_LOG_LEN 20
-
 extern const char git_usage_string[];
 extern const char git_more_info_string[];
 
@@ -104,15 +102,6 @@  extern const char git_more_info_string[];
 
 void prune_packed_objects(int);
 
-struct fmt_merge_msg_opts {
-	unsigned add_title:1,
-		credit_people:1;
-	int shortlog_len;
-};
-
-int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
-		  struct fmt_merge_msg_opts *);
-
 /**
  * If a built-in has DELAY_PAGER_CONFIG set, the built-in should call this early
  * when it wishes to respect the `pager.foo`-config. The `cmd` is the name of
diff --git a/builtin/fmt-merge-msg.c b/builtin/fmt-merge-msg.c
index 736f666f64..48a8699de7 100644
--- a/builtin/fmt-merge-msg.c
+++ b/builtin/fmt-merge-msg.c
@@ -1,666 +1,13 @@ 
 #include "builtin.h"
-#include "cache.h"
 #include "config.h"
-#include "refs.h"
-#include "object-store.h"
-#include "commit.h"
-#include "diff.h"
-#include "revision.h"
-#include "tag.h"
-#include "string-list.h"
-#include "branch.h"
 #include "fmt-merge-msg.h"
-#include "gpg-interface.h"
-#include "repository.h"
-#include "commit-reach.h"
+#include "parse-options.h"
 
 static const char * const fmt_merge_msg_usage[] = {
 	N_("git fmt-merge-msg [-m <message>] [--log[=<n>] | --no-log] [--file <file>]"),
 	NULL
 };
 
-static int use_branch_desc;
-
-int fmt_merge_msg_config(const char *key, const char *value, void *cb)
-{
-	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
-		int is_bool;
-		merge_log_config = git_config_bool_or_int(key, value, &is_bool);
-		if (!is_bool && merge_log_config < 0)
-			return error("%s: negative length %s", key, value);
-		if (is_bool && merge_log_config)
-			merge_log_config = DEFAULT_MERGE_LOG_LEN;
-	} else if (!strcmp(key, "merge.branchdesc")) {
-		use_branch_desc = git_config_bool(key, value);
-	} else {
-		return git_default_config(key, value, cb);
-	}
-	return 0;
-}
-
-/* merge data per repository where the merged tips came from */
-struct src_data {
-	struct string_list branch, tag, r_branch, generic;
-	int head_status;
-};
-
-struct origin_data {
-	struct object_id oid;
-	unsigned is_local_branch:1;
-};
-
-static void init_src_data(struct src_data *data)
-{
-	data->branch.strdup_strings = 1;
-	data->tag.strdup_strings = 1;
-	data->r_branch.strdup_strings = 1;
-	data->generic.strdup_strings = 1;
-}
-
-static struct string_list srcs = STRING_LIST_INIT_DUP;
-static struct string_list origins = STRING_LIST_INIT_DUP;
-
-struct merge_parents {
-	int alloc, nr;
-	struct merge_parent {
-		struct object_id given;
-		struct object_id commit;
-		unsigned char used;
-	} *item;
-};
-
-/*
- * I know, I know, this is inefficient, but you won't be pulling and merging
- * hundreds of heads at a time anyway.
- */
-static struct merge_parent *find_merge_parent(struct merge_parents *table,
-					      struct object_id *given,
-					      struct object_id *commit)
-{
-	int i;
-	for (i = 0; i < table->nr; i++) {
-		if (given && !oideq(&table->item[i].given, given))
-			continue;
-		if (commit && !oideq(&table->item[i].commit, commit))
-			continue;
-		return &table->item[i];
-	}
-	return NULL;
-}
-
-static void add_merge_parent(struct merge_parents *table,
-			     struct object_id *given,
-			     struct object_id *commit)
-{
-	if (table->nr && find_merge_parent(table, given, commit))
-		return;
-	ALLOC_GROW(table->item, table->nr + 1, table->alloc);
-	oidcpy(&table->item[table->nr].given, given);
-	oidcpy(&table->item[table->nr].commit, commit);
-	table->item[table->nr].used = 0;
-	table->nr++;
-}
-
-static int handle_line(char *line, struct merge_parents *merge_parents)
-{
-	int i, len = strlen(line);
-	struct origin_data *origin_data;
-	char *src;
-	const char *origin, *tag_name;
-	struct src_data *src_data;
-	struct string_list_item *item;
-	int pulling_head = 0;
-	struct object_id oid;
-	const unsigned hexsz = the_hash_algo->hexsz;
-
-	if (len < hexsz + 3 || line[hexsz] != '\t')
-		return 1;
-
-	if (starts_with(line + hexsz + 1, "not-for-merge"))
-		return 0;
-
-	if (line[hexsz + 1] != '\t')
-		return 2;
-
-	i = get_oid_hex(line, &oid);
-	if (i)
-		return 3;
-
-	if (!find_merge_parent(merge_parents, &oid, NULL))
-		return 0; /* subsumed by other parents */
-
-	origin_data = xcalloc(1, sizeof(struct origin_data));
-	oidcpy(&origin_data->oid, &oid);
-
-	if (line[len - 1] == '\n')
-		line[len - 1] = 0;
-	line += hexsz + 2;
-
-	/*
-	 * At this point, line points at the beginning of comment e.g.
-	 * "branch 'frotz' of git://that/repository.git".
-	 * Find the repository name and point it with src.
-	 */
-	src = strstr(line, " of ");
-	if (src) {
-		*src = 0;
-		src += 4;
-		pulling_head = 0;
-	} else {
-		src = line;
-		pulling_head = 1;
-	}
-
-	item = unsorted_string_list_lookup(&srcs, src);
-	if (!item) {
-		item = string_list_append(&srcs, src);
-		item->util = xcalloc(1, sizeof(struct src_data));
-		init_src_data(item->util);
-	}
-	src_data = item->util;
-
-	if (pulling_head) {
-		origin = src;
-		src_data->head_status |= 1;
-	} else if (skip_prefix(line, "branch ", &origin)) {
-		origin_data->is_local_branch = 1;
-		string_list_append(&src_data->branch, origin);
-		src_data->head_status |= 2;
-	} else if (skip_prefix(line, "tag ", &tag_name)) {
-		origin = line;
-		string_list_append(&src_data->tag, tag_name);
-		src_data->head_status |= 2;
-	} else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
-		string_list_append(&src_data->r_branch, origin);
-		src_data->head_status |= 2;
-	} else {
-		origin = src;
-		string_list_append(&src_data->generic, line);
-		src_data->head_status |= 2;
-	}
-
-	if (!strcmp(".", src) || !strcmp(src, origin)) {
-		int len = strlen(origin);
-		if (origin[0] == '\'' && origin[len - 1] == '\'')
-			origin = xmemdupz(origin + 1, len - 2);
-	} else
-		origin = xstrfmt("%s of %s", origin, src);
-	if (strcmp(".", src))
-		origin_data->is_local_branch = 0;
-	string_list_append(&origins, origin)->util = origin_data;
-	return 0;
-}
-
-static void print_joined(const char *singular, const char *plural,
-		struct string_list *list, struct strbuf *out)
-{
-	if (list->nr == 0)
-		return;
-	if (list->nr == 1) {
-		strbuf_addf(out, "%s%s", singular, list->items[0].string);
-	} else {
-		int i;
-		strbuf_addstr(out, plural);
-		for (i = 0; i < list->nr - 1; i++)
-			strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
-				    list->items[i].string);
-		strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
-	}
-}
-
-static void add_branch_desc(struct strbuf *out, const char *name)
-{
-	struct strbuf desc = STRBUF_INIT;
-
-	if (!read_branch_desc(&desc, name)) {
-		const char *bp = desc.buf;
-		while (*bp) {
-			const char *ep = strchrnul(bp, '\n');
-			if (*ep)
-				ep++;
-			strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
-			bp = ep;
-		}
-		strbuf_complete_line(out);
-	}
-	strbuf_release(&desc);
-}
-
-#define util_as_integral(elem) ((intptr_t)((elem)->util))
-
-static void record_person_from_buf(int which, struct string_list *people,
-				   const char *buffer)
-{
-	char *name_buf, *name, *name_end;
-	struct string_list_item *elem;
-	const char *field;
-
-	field = (which == 'a') ? "\nauthor " : "\ncommitter ";
-	name = strstr(buffer, field);
-	if (!name)
-		return;
-	name += strlen(field);
-	name_end = strchrnul(name, '<');
-	if (*name_end)
-		name_end--;
-	while (isspace(*name_end) && name <= name_end)
-		name_end--;
-	if (name_end < name)
-		return;
-	name_buf = xmemdupz(name, name_end - name + 1);
-
-	elem = string_list_lookup(people, name_buf);
-	if (!elem) {
-		elem = string_list_insert(people, name_buf);
-		elem->util = (void *)0;
-	}
-	elem->util = (void*)(util_as_integral(elem) + 1);
-	free(name_buf);
-}
-
-
-static void record_person(int which, struct string_list *people,
-			  struct commit *commit)
-{
-	const char *buffer = get_commit_buffer(commit, NULL);
-	record_person_from_buf(which, people, buffer);
-	unuse_commit_buffer(commit, buffer);
-}
-
-static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
-{
-	const struct string_list_item *a = a_, *b = b_;
-	return util_as_integral(b) - util_as_integral(a);
-}
-
-static void add_people_count(struct strbuf *out, struct string_list *people)
-{
-	if (people->nr == 1)
-		strbuf_addstr(out, people->items[0].string);
-	else if (people->nr == 2)
-		strbuf_addf(out, "%s (%d) and %s (%d)",
-			    people->items[0].string,
-			    (int)util_as_integral(&people->items[0]),
-			    people->items[1].string,
-			    (int)util_as_integral(&people->items[1]));
-	else if (people->nr)
-		strbuf_addf(out, "%s (%d) and others",
-			    people->items[0].string,
-			    (int)util_as_integral(&people->items[0]));
-}
-
-static void credit_people(struct strbuf *out,
-			  struct string_list *them,
-			  int kind)
-{
-	const char *label;
-	const char *me;
-
-	if (kind == 'a') {
-		label = "By";
-		me = git_author_info(IDENT_NO_DATE);
-	} else {
-		label = "Via";
-		me = git_committer_info(IDENT_NO_DATE);
-	}
-
-	if (!them->nr ||
-	    (them->nr == 1 &&
-	     me &&
-	     skip_prefix(me, them->items->string, &me) &&
-	     starts_with(me, " <")))
-		return;
-	strbuf_addf(out, "\n%c %s ", comment_line_char, label);
-	add_people_count(out, them);
-}
-
-static void add_people_info(struct strbuf *out,
-			    struct string_list *authors,
-			    struct string_list *committers)
-{
-	QSORT(authors->items, authors->nr,
-	      cmp_string_list_util_as_integral);
-	QSORT(committers->items, committers->nr,
-	      cmp_string_list_util_as_integral);
-
-	credit_people(out, authors, 'a');
-	credit_people(out, committers, 'c');
-}
-
-static void shortlog(const char *name,
-		     struct origin_data *origin_data,
-		     struct commit *head,
-		     struct rev_info *rev,
-		     struct fmt_merge_msg_opts *opts,
-		     struct strbuf *out)
-{
-	int i, count = 0;
-	struct commit *commit;
-	struct object *branch;
-	struct string_list subjects = STRING_LIST_INIT_DUP;
-	struct string_list authors = STRING_LIST_INIT_DUP;
-	struct string_list committers = STRING_LIST_INIT_DUP;
-	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
-	struct strbuf sb = STRBUF_INIT;
-	const struct object_id *oid = &origin_data->oid;
-	int limit = opts->shortlog_len;
-
-	branch = deref_tag(the_repository, parse_object(the_repository, oid),
-			   oid_to_hex(oid),
-			   the_hash_algo->hexsz);
-	if (!branch || branch->type != OBJ_COMMIT)
-		return;
-
-	setup_revisions(0, NULL, rev, NULL);
-	add_pending_object(rev, branch, name);
-	add_pending_object(rev, &head->object, "^HEAD");
-	head->object.flags |= UNINTERESTING;
-	if (prepare_revision_walk(rev))
-		die("revision walk setup failed");
-	while ((commit = get_revision(rev)) != NULL) {
-		struct pretty_print_context ctx = {0};
-
-		if (commit->parents && commit->parents->next) {
-			/* do not list a merge but count committer */
-			if (opts->credit_people)
-				record_person('c', &committers, commit);
-			continue;
-		}
-		if (!count && opts->credit_people)
-			/* the 'tip' committer */
-			record_person('c', &committers, commit);
-		if (opts->credit_people)
-			record_person('a', &authors, commit);
-		count++;
-		if (subjects.nr > limit)
-			continue;
-
-		format_commit_message(commit, "%s", &sb, &ctx);
-		strbuf_ltrim(&sb);
-
-		if (!sb.len)
-			string_list_append(&subjects,
-					   oid_to_hex(&commit->object.oid));
-		else
-			string_list_append_nodup(&subjects,
-						 strbuf_detach(&sb, NULL));
-	}
-
-	if (opts->credit_people)
-		add_people_info(out, &authors, &committers);
-	if (count > limit)
-		strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
-	else
-		strbuf_addf(out, "\n* %s:\n", name);
-
-	if (origin_data->is_local_branch && use_branch_desc)
-		add_branch_desc(out, name);
-
-	for (i = 0; i < subjects.nr; i++)
-		if (i >= limit)
-			strbuf_addstr(out, "  ...\n");
-		else
-			strbuf_addf(out, "  %s\n", subjects.items[i].string);
-
-	clear_commit_marks((struct commit *)branch, flags);
-	clear_commit_marks(head, flags);
-	free_commit_list(rev->commits);
-	rev->commits = NULL;
-	rev->pending.nr = 0;
-
-	string_list_clear(&authors, 0);
-	string_list_clear(&committers, 0);
-	string_list_clear(&subjects, 0);
-}
-
-static void fmt_merge_msg_title(struct strbuf *out,
-				const char *current_branch)
-{
-	int i = 0;
-	char *sep = "";
-
-	strbuf_addstr(out, "Merge ");
-	for (i = 0; i < srcs.nr; i++) {
-		struct src_data *src_data = srcs.items[i].util;
-		const char *subsep = "";
-
-		strbuf_addstr(out, sep);
-		sep = "; ";
-
-		if (src_data->head_status == 1) {
-			strbuf_addstr(out, srcs.items[i].string);
-			continue;
-		}
-		if (src_data->head_status == 3) {
-			subsep = ", ";
-			strbuf_addstr(out, "HEAD");
-		}
-		if (src_data->branch.nr) {
-			strbuf_addstr(out, subsep);
-			subsep = ", ";
-			print_joined("branch ", "branches ", &src_data->branch,
-					out);
-		}
-		if (src_data->r_branch.nr) {
-			strbuf_addstr(out, subsep);
-			subsep = ", ";
-			print_joined("remote-tracking branch ", "remote-tracking branches ",
-					&src_data->r_branch, out);
-		}
-		if (src_data->tag.nr) {
-			strbuf_addstr(out, subsep);
-			subsep = ", ";
-			print_joined("tag ", "tags ", &src_data->tag, out);
-		}
-		if (src_data->generic.nr) {
-			strbuf_addstr(out, subsep);
-			print_joined("commit ", "commits ", &src_data->generic,
-					out);
-		}
-		if (strcmp(".", srcs.items[i].string))
-			strbuf_addf(out, " of %s", srcs.items[i].string);
-	}
-
-	if (!strcmp("master", current_branch))
-		strbuf_addch(out, '\n');
-	else
-		strbuf_addf(out, " into %s\n", current_branch);
-}
-
-static void fmt_tag_signature(struct strbuf *tagbuf,
-			      struct strbuf *sig,
-			      const char *buf,
-			      unsigned long len)
-{
-	const char *tag_body = strstr(buf, "\n\n");
-	if (tag_body) {
-		tag_body += 2;
-		strbuf_add(tagbuf, tag_body, buf + len - tag_body);
-	}
-	strbuf_complete_line(tagbuf);
-	if (sig->len) {
-		strbuf_addch(tagbuf, '\n');
-		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
-	}
-}
-
-static void fmt_merge_msg_sigs(struct strbuf *out)
-{
-	int i, tag_number = 0, first_tag = 0;
-	struct strbuf tagbuf = STRBUF_INIT;
-
-	for (i = 0; i < origins.nr; i++) {
-		struct object_id *oid = origins.items[i].util;
-		enum object_type type;
-		unsigned long size, len;
-		char *buf = read_object_file(oid, &type, &size);
-		struct strbuf sig = STRBUF_INIT;
-
-		if (!buf || type != OBJ_TAG)
-			goto next;
-		len = parse_signature(buf, size);
-
-		if (size == len)
-			; /* merely annotated */
-		else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
-			if (!sig.len)
-				strbuf_addstr(&sig, "gpg verification failed.\n");
-		}
-
-		if (!tag_number++) {
-			fmt_tag_signature(&tagbuf, &sig, buf, len);
-			first_tag = i;
-		} else {
-			if (tag_number == 2) {
-				struct strbuf tagline = STRBUF_INIT;
-				strbuf_addch(&tagline, '\n');
-				strbuf_add_commented_lines(&tagline,
-						origins.items[first_tag].string,
-						strlen(origins.items[first_tag].string));
-				strbuf_insert(&tagbuf, 0, tagline.buf,
-					      tagline.len);
-				strbuf_release(&tagline);
-			}
-			strbuf_addch(&tagbuf, '\n');
-			strbuf_add_commented_lines(&tagbuf,
-					origins.items[i].string,
-					strlen(origins.items[i].string));
-			fmt_tag_signature(&tagbuf, &sig, buf, len);
-		}
-		strbuf_release(&sig);
-	next:
-		free(buf);
-	}
-	if (tagbuf.len) {
-		strbuf_addch(out, '\n');
-		strbuf_addbuf(out, &tagbuf);
-	}
-	strbuf_release(&tagbuf);
-}
-
-static void find_merge_parents(struct merge_parents *result,
-			       struct strbuf *in, struct object_id *head)
-{
-	struct commit_list *parents;
-	struct commit *head_commit;
-	int pos = 0, i, j;
-
-	parents = NULL;
-	while (pos < in->len) {
-		int len;
-		char *p = in->buf + pos;
-		char *newline = strchr(p, '\n');
-		const char *q;
-		struct object_id oid;
-		struct commit *parent;
-		struct object *obj;
-
-		len = newline ? newline - p : strlen(p);
-		pos += len + !!newline;
-
-		if (parse_oid_hex(p, &oid, &q) ||
-		    q[0] != '\t' ||
-		    q[1] != '\t')
-			continue; /* skip not-for-merge */
-		/*
-		 * Do not use get_merge_parent() here; we do not have
-		 * "name" here and we do not want to contaminate its
-		 * util field yet.
-		 */
-		obj = parse_object(the_repository, &oid);
-		parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
-		if (!parent)
-			continue;
-		commit_list_insert(parent, &parents);
-		add_merge_parent(result, &obj->oid, &parent->object.oid);
-	}
-	head_commit = lookup_commit(the_repository, head);
-	if (head_commit)
-		commit_list_insert(head_commit, &parents);
-	reduce_heads_replace(&parents);
-
-	while (parents) {
-		struct commit *cmit = pop_commit(&parents);
-		for (i = 0; i < result->nr; i++)
-			if (oideq(&result->item[i].commit, &cmit->object.oid))
-				result->item[i].used = 1;
-	}
-
-	for (i = j = 0; i < result->nr; i++) {
-		if (result->item[i].used) {
-			if (i != j)
-				result->item[j] = result->item[i];
-			j++;
-		}
-	}
-	result->nr = j;
-}
-
-int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
-		  struct fmt_merge_msg_opts *opts)
-{
-	int i = 0, pos = 0;
-	struct object_id head_oid;
-	const char *current_branch;
-	void *current_branch_to_free;
-	struct merge_parents merge_parents;
-
-	memset(&merge_parents, 0, sizeof(merge_parents));
-
-	/* get current branch */
-	current_branch = current_branch_to_free =
-		resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
-	if (!current_branch)
-		die("No current branch");
-	if (starts_with(current_branch, "refs/heads/"))
-		current_branch += 11;
-
-	find_merge_parents(&merge_parents, in, &head_oid);
-
-	/* get a line */
-	while (pos < in->len) {
-		int len;
-		char *newline, *p = in->buf + pos;
-
-		newline = strchr(p, '\n');
-		len = newline ? newline - p : strlen(p);
-		pos += len + !!newline;
-		i++;
-		p[len] = 0;
-		if (handle_line(p, &merge_parents))
-			die("error in line %d: %.*s", i, len, p);
-	}
-
-	if (opts->add_title && srcs.nr)
-		fmt_merge_msg_title(out, current_branch);
-
-	if (origins.nr)
-		fmt_merge_msg_sigs(out);
-
-	if (opts->shortlog_len) {
-		struct commit *head;
-		struct rev_info rev;
-
-		head = lookup_commit_or_die(&head_oid, "HEAD");
-		repo_init_revisions(the_repository, &rev, NULL);
-		rev.commit_format = CMIT_FMT_ONELINE;
-		rev.ignore_merges = 1;
-		rev.limited = 1;
-
-		strbuf_complete_line(out);
-
-		for (i = 0; i < origins.nr; i++)
-			shortlog(origins.items[i].string,
-				 origins.items[i].util,
-				 head, &rev, opts, out);
-	}
-
-	strbuf_complete_line(out);
-	free(current_branch_to_free);
-	free(merge_parents.item);
-	return 0;
-}
-
 int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
 {
 	const char *inpath = NULL;
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
new file mode 100644
index 0000000000..5bcd4fd1c6
--- /dev/null
+++ b/fmt-merge-msg.c
@@ -0,0 +1,653 @@ 
+#include "config.h"
+#include "refs.h"
+#include "object-store.h"
+#include "diff.h"
+#include "revision.h"
+#include "tag.h"
+#include "string-list.h"
+#include "branch.h"
+#include "fmt-merge-msg.h"
+#include "commit-reach.h"
+
+static int use_branch_desc;
+
+int fmt_merge_msg_config(const char *key, const char *value, void *cb)
+{
+	if (!strcmp(key, "merge.log") || !strcmp(key, "merge.summary")) {
+		int is_bool;
+		merge_log_config = git_config_bool_or_int(key, value, &is_bool);
+		if (!is_bool && merge_log_config < 0)
+			return error("%s: negative length %s", key, value);
+		if (is_bool && merge_log_config)
+			merge_log_config = DEFAULT_MERGE_LOG_LEN;
+	} else if (!strcmp(key, "merge.branchdesc")) {
+		use_branch_desc = git_config_bool(key, value);
+	} else {
+		return git_default_config(key, value, cb);
+	}
+	return 0;
+}
+
+/* merge data per repository where the merged tips came from */
+struct src_data {
+	struct string_list branch, tag, r_branch, generic;
+	int head_status;
+};
+
+struct origin_data {
+	struct object_id oid;
+	unsigned is_local_branch:1;
+};
+
+static void init_src_data(struct src_data *data)
+{
+	data->branch.strdup_strings = 1;
+	data->tag.strdup_strings = 1;
+	data->r_branch.strdup_strings = 1;
+	data->generic.strdup_strings = 1;
+}
+
+static struct string_list srcs = STRING_LIST_INIT_DUP;
+static struct string_list origins = STRING_LIST_INIT_DUP;
+
+struct merge_parents {
+	int alloc, nr;
+	struct merge_parent {
+		struct object_id given;
+		struct object_id commit;
+		unsigned char used;
+	} *item;
+};
+
+/*
+ * I know, I know, this is inefficient, but you won't be pulling and merging
+ * hundreds of heads at a time anyway.
+ */
+static struct merge_parent *find_merge_parent(struct merge_parents *table,
+					      struct object_id *given,
+					      struct object_id *commit)
+{
+	int i;
+	for (i = 0; i < table->nr; i++) {
+		if (given && !oideq(&table->item[i].given, given))
+			continue;
+		if (commit && !oideq(&table->item[i].commit, commit))
+			continue;
+		return &table->item[i];
+	}
+	return NULL;
+}
+
+static void add_merge_parent(struct merge_parents *table,
+			     struct object_id *given,
+			     struct object_id *commit)
+{
+	if (table->nr && find_merge_parent(table, given, commit))
+		return;
+	ALLOC_GROW(table->item, table->nr + 1, table->alloc);
+	oidcpy(&table->item[table->nr].given, given);
+	oidcpy(&table->item[table->nr].commit, commit);
+	table->item[table->nr].used = 0;
+	table->nr++;
+}
+
+static int handle_line(char *line, struct merge_parents *merge_parents)
+{
+	int i, len = strlen(line);
+	struct origin_data *origin_data;
+	char *src;
+	const char *origin, *tag_name;
+	struct src_data *src_data;
+	struct string_list_item *item;
+	int pulling_head = 0;
+	struct object_id oid;
+	const unsigned hexsz = the_hash_algo->hexsz;
+
+	if (len < hexsz + 3 || line[hexsz] != '\t')
+		return 1;
+
+	if (starts_with(line + hexsz + 1, "not-for-merge"))
+		return 0;
+
+	if (line[hexsz + 1] != '\t')
+		return 2;
+
+	i = get_oid_hex(line, &oid);
+	if (i)
+		return 3;
+
+	if (!find_merge_parent(merge_parents, &oid, NULL))
+		return 0; /* subsumed by other parents */
+
+	origin_data = xcalloc(1, sizeof(struct origin_data));
+	oidcpy(&origin_data->oid, &oid);
+
+	if (line[len - 1] == '\n')
+		line[len - 1] = 0;
+	line += hexsz + 2;
+
+	/*
+	 * At this point, line points at the beginning of comment e.g.
+	 * "branch 'frotz' of git://that/repository.git".
+	 * Find the repository name and point it with src.
+	 */
+	src = strstr(line, " of ");
+	if (src) {
+		*src = 0;
+		src += 4;
+		pulling_head = 0;
+	} else {
+		src = line;
+		pulling_head = 1;
+	}
+
+	item = unsorted_string_list_lookup(&srcs, src);
+	if (!item) {
+		item = string_list_append(&srcs, src);
+		item->util = xcalloc(1, sizeof(struct src_data));
+		init_src_data(item->util);
+	}
+	src_data = item->util;
+
+	if (pulling_head) {
+		origin = src;
+		src_data->head_status |= 1;
+	} else if (skip_prefix(line, "branch ", &origin)) {
+		origin_data->is_local_branch = 1;
+		string_list_append(&src_data->branch, origin);
+		src_data->head_status |= 2;
+	} else if (skip_prefix(line, "tag ", &tag_name)) {
+		origin = line;
+		string_list_append(&src_data->tag, tag_name);
+		src_data->head_status |= 2;
+	} else if (skip_prefix(line, "remote-tracking branch ", &origin)) {
+		string_list_append(&src_data->r_branch, origin);
+		src_data->head_status |= 2;
+	} else {
+		origin = src;
+		string_list_append(&src_data->generic, line);
+		src_data->head_status |= 2;
+	}
+
+	if (!strcmp(".", src) || !strcmp(src, origin)) {
+		int len = strlen(origin);
+		if (origin[0] == '\'' && origin[len - 1] == '\'')
+			origin = xmemdupz(origin + 1, len - 2);
+	} else
+		origin = xstrfmt("%s of %s", origin, src);
+	if (strcmp(".", src))
+		origin_data->is_local_branch = 0;
+	string_list_append(&origins, origin)->util = origin_data;
+	return 0;
+}
+
+static void print_joined(const char *singular, const char *plural,
+		struct string_list *list, struct strbuf *out)
+{
+	if (list->nr == 0)
+		return;
+	if (list->nr == 1) {
+		strbuf_addf(out, "%s%s", singular, list->items[0].string);
+	} else {
+		int i;
+		strbuf_addstr(out, plural);
+		for (i = 0; i < list->nr - 1; i++)
+			strbuf_addf(out, "%s%s", i > 0 ? ", " : "",
+				    list->items[i].string);
+		strbuf_addf(out, " and %s", list->items[list->nr - 1].string);
+	}
+}
+
+static void add_branch_desc(struct strbuf *out, const char *name)
+{
+	struct strbuf desc = STRBUF_INIT;
+
+	if (!read_branch_desc(&desc, name)) {
+		const char *bp = desc.buf;
+		while (*bp) {
+			const char *ep = strchrnul(bp, '\n');
+			if (*ep)
+				ep++;
+			strbuf_addf(out, "  : %.*s", (int)(ep - bp), bp);
+			bp = ep;
+		}
+		strbuf_complete_line(out);
+	}
+	strbuf_release(&desc);
+}
+
+#define util_as_integral(elem) ((intptr_t)((elem)->util))
+
+static void record_person_from_buf(int which, struct string_list *people,
+				   const char *buffer)
+{
+	char *name_buf, *name, *name_end;
+	struct string_list_item *elem;
+	const char *field;
+
+	field = (which == 'a') ? "\nauthor " : "\ncommitter ";
+	name = strstr(buffer, field);
+	if (!name)
+		return;
+	name += strlen(field);
+	name_end = strchrnul(name, '<');
+	if (*name_end)
+		name_end--;
+	while (isspace(*name_end) && name <= name_end)
+		name_end--;
+	if (name_end < name)
+		return;
+	name_buf = xmemdupz(name, name_end - name + 1);
+
+	elem = string_list_lookup(people, name_buf);
+	if (!elem) {
+		elem = string_list_insert(people, name_buf);
+		elem->util = (void *)0;
+	}
+	elem->util = (void*)(util_as_integral(elem) + 1);
+	free(name_buf);
+}
+
+
+static void record_person(int which, struct string_list *people,
+			  struct commit *commit)
+{
+	const char *buffer = get_commit_buffer(commit, NULL);
+	record_person_from_buf(which, people, buffer);
+	unuse_commit_buffer(commit, buffer);
+}
+
+static int cmp_string_list_util_as_integral(const void *a_, const void *b_)
+{
+	const struct string_list_item *a = a_, *b = b_;
+	return util_as_integral(b) - util_as_integral(a);
+}
+
+static void add_people_count(struct strbuf *out, struct string_list *people)
+{
+	if (people->nr == 1)
+		strbuf_addstr(out, people->items[0].string);
+	else if (people->nr == 2)
+		strbuf_addf(out, "%s (%d) and %s (%d)",
+			    people->items[0].string,
+			    (int)util_as_integral(&people->items[0]),
+			    people->items[1].string,
+			    (int)util_as_integral(&people->items[1]));
+	else if (people->nr)
+		strbuf_addf(out, "%s (%d) and others",
+			    people->items[0].string,
+			    (int)util_as_integral(&people->items[0]));
+}
+
+static void credit_people(struct strbuf *out,
+			  struct string_list *them,
+			  int kind)
+{
+	const char *label;
+	const char *me;
+
+	if (kind == 'a') {
+		label = "By";
+		me = git_author_info(IDENT_NO_DATE);
+	} else {
+		label = "Via";
+		me = git_committer_info(IDENT_NO_DATE);
+	}
+
+	if (!them->nr ||
+	    (them->nr == 1 &&
+	     me &&
+	     skip_prefix(me, them->items->string, &me) &&
+	     starts_with(me, " <")))
+		return;
+	strbuf_addf(out, "\n%c %s ", comment_line_char, label);
+	add_people_count(out, them);
+}
+
+static void add_people_info(struct strbuf *out,
+			    struct string_list *authors,
+			    struct string_list *committers)
+{
+	QSORT(authors->items, authors->nr,
+	      cmp_string_list_util_as_integral);
+	QSORT(committers->items, committers->nr,
+	      cmp_string_list_util_as_integral);
+
+	credit_people(out, authors, 'a');
+	credit_people(out, committers, 'c');
+}
+
+static void shortlog(const char *name,
+		     struct origin_data *origin_data,
+		     struct commit *head,
+		     struct rev_info *rev,
+		     struct fmt_merge_msg_opts *opts,
+		     struct strbuf *out)
+{
+	int i, count = 0;
+	struct commit *commit;
+	struct object *branch;
+	struct string_list subjects = STRING_LIST_INIT_DUP;
+	struct string_list authors = STRING_LIST_INIT_DUP;
+	struct string_list committers = STRING_LIST_INIT_DUP;
+	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
+	struct strbuf sb = STRBUF_INIT;
+	const struct object_id *oid = &origin_data->oid;
+	int limit = opts->shortlog_len;
+
+	branch = deref_tag(the_repository, parse_object(the_repository, oid),
+			   oid_to_hex(oid),
+			   the_hash_algo->hexsz);
+	if (!branch || branch->type != OBJ_COMMIT)
+		return;
+
+	setup_revisions(0, NULL, rev, NULL);
+	add_pending_object(rev, branch, name);
+	add_pending_object(rev, &head->object, "^HEAD");
+	head->object.flags |= UNINTERESTING;
+	if (prepare_revision_walk(rev))
+		die("revision walk setup failed");
+	while ((commit = get_revision(rev)) != NULL) {
+		struct pretty_print_context ctx = {0};
+
+		if (commit->parents && commit->parents->next) {
+			/* do not list a merge but count committer */
+			if (opts->credit_people)
+				record_person('c', &committers, commit);
+			continue;
+		}
+		if (!count && opts->credit_people)
+			/* the 'tip' committer */
+			record_person('c', &committers, commit);
+		if (opts->credit_people)
+			record_person('a', &authors, commit);
+		count++;
+		if (subjects.nr > limit)
+			continue;
+
+		format_commit_message(commit, "%s", &sb, &ctx);
+		strbuf_ltrim(&sb);
+
+		if (!sb.len)
+			string_list_append(&subjects,
+					   oid_to_hex(&commit->object.oid));
+		else
+			string_list_append_nodup(&subjects,
+						 strbuf_detach(&sb, NULL));
+	}
+
+	if (opts->credit_people)
+		add_people_info(out, &authors, &committers);
+	if (count > limit)
+		strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
+	else
+		strbuf_addf(out, "\n* %s:\n", name);
+
+	if (origin_data->is_local_branch && use_branch_desc)
+		add_branch_desc(out, name);
+
+	for (i = 0; i < subjects.nr; i++)
+		if (i >= limit)
+			strbuf_addstr(out, "  ...\n");
+		else
+			strbuf_addf(out, "  %s\n", subjects.items[i].string);
+
+	clear_commit_marks((struct commit *)branch, flags);
+	clear_commit_marks(head, flags);
+	free_commit_list(rev->commits);
+	rev->commits = NULL;
+	rev->pending.nr = 0;
+
+	string_list_clear(&authors, 0);
+	string_list_clear(&committers, 0);
+	string_list_clear(&subjects, 0);
+}
+
+static void fmt_merge_msg_title(struct strbuf *out,
+				const char *current_branch)
+{
+	int i = 0;
+	char *sep = "";
+
+	strbuf_addstr(out, "Merge ");
+	for (i = 0; i < srcs.nr; i++) {
+		struct src_data *src_data = srcs.items[i].util;
+		const char *subsep = "";
+
+		strbuf_addstr(out, sep);
+		sep = "; ";
+
+		if (src_data->head_status == 1) {
+			strbuf_addstr(out, srcs.items[i].string);
+			continue;
+		}
+		if (src_data->head_status == 3) {
+			subsep = ", ";
+			strbuf_addstr(out, "HEAD");
+		}
+		if (src_data->branch.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("branch ", "branches ", &src_data->branch,
+					out);
+		}
+		if (src_data->r_branch.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("remote-tracking branch ", "remote-tracking branches ",
+					&src_data->r_branch, out);
+		}
+		if (src_data->tag.nr) {
+			strbuf_addstr(out, subsep);
+			subsep = ", ";
+			print_joined("tag ", "tags ", &src_data->tag, out);
+		}
+		if (src_data->generic.nr) {
+			strbuf_addstr(out, subsep);
+			print_joined("commit ", "commits ", &src_data->generic,
+					out);
+		}
+		if (strcmp(".", srcs.items[i].string))
+			strbuf_addf(out, " of %s", srcs.items[i].string);
+	}
+
+	if (!strcmp("master", current_branch))
+		strbuf_addch(out, '\n');
+	else
+		strbuf_addf(out, " into %s\n", current_branch);
+}
+
+static void fmt_tag_signature(struct strbuf *tagbuf,
+			      struct strbuf *sig,
+			      const char *buf,
+			      unsigned long len)
+{
+	const char *tag_body = strstr(buf, "\n\n");
+	if (tag_body) {
+		tag_body += 2;
+		strbuf_add(tagbuf, tag_body, buf + len - tag_body);
+	}
+	strbuf_complete_line(tagbuf);
+	if (sig->len) {
+		strbuf_addch(tagbuf, '\n');
+		strbuf_add_commented_lines(tagbuf, sig->buf, sig->len);
+	}
+}
+
+static void fmt_merge_msg_sigs(struct strbuf *out)
+{
+	int i, tag_number = 0, first_tag = 0;
+	struct strbuf tagbuf = STRBUF_INIT;
+
+	for (i = 0; i < origins.nr; i++) {
+		struct object_id *oid = origins.items[i].util;
+		enum object_type type;
+		unsigned long size, len;
+		char *buf = read_object_file(oid, &type, &size);
+		struct strbuf sig = STRBUF_INIT;
+
+		if (!buf || type != OBJ_TAG)
+			goto next;
+		len = parse_signature(buf, size);
+
+		if (size == len)
+			; /* merely annotated */
+		else if (verify_signed_buffer(buf, len, buf + len, size - len, &sig, NULL)) {
+			if (!sig.len)
+				strbuf_addstr(&sig, "gpg verification failed.\n");
+		}
+
+		if (!tag_number++) {
+			fmt_tag_signature(&tagbuf, &sig, buf, len);
+			first_tag = i;
+		} else {
+			if (tag_number == 2) {
+				struct strbuf tagline = STRBUF_INIT;
+				strbuf_addch(&tagline, '\n');
+				strbuf_add_commented_lines(&tagline,
+						origins.items[first_tag].string,
+						strlen(origins.items[first_tag].string));
+				strbuf_insert(&tagbuf, 0, tagline.buf,
+					      tagline.len);
+				strbuf_release(&tagline);
+			}
+			strbuf_addch(&tagbuf, '\n');
+			strbuf_add_commented_lines(&tagbuf,
+					origins.items[i].string,
+					strlen(origins.items[i].string));
+			fmt_tag_signature(&tagbuf, &sig, buf, len);
+		}
+		strbuf_release(&sig);
+	next:
+		free(buf);
+	}
+	if (tagbuf.len) {
+		strbuf_addch(out, '\n');
+		strbuf_addbuf(out, &tagbuf);
+	}
+	strbuf_release(&tagbuf);
+}
+
+static void find_merge_parents(struct merge_parents *result,
+			       struct strbuf *in, struct object_id *head)
+{
+	struct commit_list *parents;
+	struct commit *head_commit;
+	int pos = 0, i, j;
+
+	parents = NULL;
+	while (pos < in->len) {
+		int len;
+		char *p = in->buf + pos;
+		char *newline = strchr(p, '\n');
+		const char *q;
+		struct object_id oid;
+		struct commit *parent;
+		struct object *obj;
+
+		len = newline ? newline - p : strlen(p);
+		pos += len + !!newline;
+
+		if (parse_oid_hex(p, &oid, &q) ||
+		    q[0] != '\t' ||
+		    q[1] != '\t')
+			continue; /* skip not-for-merge */
+		/*
+		 * Do not use get_merge_parent() here; we do not have
+		 * "name" here and we do not want to contaminate its
+		 * util field yet.
+		 */
+		obj = parse_object(the_repository, &oid);
+		parent = (struct commit *)peel_to_type(NULL, 0, obj, OBJ_COMMIT);
+		if (!parent)
+			continue;
+		commit_list_insert(parent, &parents);
+		add_merge_parent(result, &obj->oid, &parent->object.oid);
+	}
+	head_commit = lookup_commit(the_repository, head);
+	if (head_commit)
+		commit_list_insert(head_commit, &parents);
+	reduce_heads_replace(&parents);
+
+	while (parents) {
+		struct commit *cmit = pop_commit(&parents);
+		for (i = 0; i < result->nr; i++)
+			if (oideq(&result->item[i].commit, &cmit->object.oid))
+				result->item[i].used = 1;
+	}
+
+	for (i = j = 0; i < result->nr; i++) {
+		if (result->item[i].used) {
+			if (i != j)
+				result->item[j] = result->item[i];
+			j++;
+		}
+	}
+	result->nr = j;
+}
+
+
+int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+		  struct fmt_merge_msg_opts *opts)
+{
+	int i = 0, pos = 0;
+	struct object_id head_oid;
+	const char *current_branch;
+	void *current_branch_to_free;
+	struct merge_parents merge_parents;
+
+	memset(&merge_parents, 0, sizeof(merge_parents));
+
+	/* get current branch */
+	current_branch = current_branch_to_free =
+		resolve_refdup("HEAD", RESOLVE_REF_READING, &head_oid, NULL);
+	if (!current_branch)
+		die("No current branch");
+	if (starts_with(current_branch, "refs/heads/"))
+		current_branch += 11;
+
+	find_merge_parents(&merge_parents, in, &head_oid);
+
+	/* get a line */
+	while (pos < in->len) {
+		int len;
+		char *newline, *p = in->buf + pos;
+
+		newline = strchr(p, '\n');
+		len = newline ? newline - p : strlen(p);
+		pos += len + !!newline;
+		i++;
+		p[len] = 0;
+		if (handle_line(p, &merge_parents))
+			die("error in line %d: %.*s", i, len, p);
+	}
+
+	if (opts->add_title && srcs.nr)
+		fmt_merge_msg_title(out, current_branch);
+
+	if (origins.nr)
+		fmt_merge_msg_sigs(out);
+
+	if (opts->shortlog_len) {
+		struct commit *head;
+		struct rev_info rev;
+
+		head = lookup_commit_or_die(&head_oid, "HEAD");
+		repo_init_revisions(the_repository, &rev, NULL);
+		rev.commit_format = CMIT_FMT_ONELINE;
+		rev.ignore_merges = 1;
+		rev.limited = 1;
+
+		strbuf_complete_line(out);
+
+		for (i = 0; i < origins.nr; i++)
+			shortlog(origins.items[i].string,
+				 origins.items[i].util,
+				 head, &rev, opts, out);
+	}
+
+	strbuf_complete_line(out);
+	free(current_branch_to_free);
+	free(merge_parents.item);
+	return 0;
+}
diff --git a/fmt-merge-msg.h b/fmt-merge-msg.h
index 01e3aa88c5..f2ab0e0085 100644
--- a/fmt-merge-msg.h
+++ b/fmt-merge-msg.h
@@ -1,7 +1,20 @@ 
 #ifndef FMT_MERGE_MSG_H
 #define FMT_MERGE_MSG_H
 
+#include "strbuf.h"
+
+#define DEFAULT_MERGE_LOG_LEN 20
+
+struct fmt_merge_msg_opts {
+	unsigned add_title:1,
+		credit_people:1;
+	int shortlog_len;
+};
+
 extern int merge_log_config;
 int fmt_merge_msg_config(const char *key, const char *value, void *cb);
+int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
+		  struct fmt_merge_msg_opts *);
+
 
 #endif /* FMT_MERGE_MSG_H */