1 files changed, 383 insertions, 0 deletions
diff --git a/builtin-fmt-merge-msg.c b/builtin-fmt-merge-msg.c
new file mode 100644
index 000000000..df18f4070
--- /dev/null
+++ b/builtin-fmt-merge-msg.c
@@ -0,0 +1,383 @@
+#include "builtin.h"
+#include "cache.h"
+#include "commit.h"
+#include "diff.h"
+#include "revision.h"
+#include "tag.h"
+
+static const char * const fmt_merge_msg_usage[] = {
+	"git fmt-merge-msg [--log|--no-log] [--file <file>]",
+	NULL
+};
+
+static int merge_summary;
+
+static int fmt_merge_msg_config(const char *key, const char *value, void *cb)
+{
+	static int found_merge_log = 0;
+	if (!strcmp("merge.log", key)) {
+		found_merge_log = 1;
+		merge_summary = git_config_bool(key, value);
+	}
+	if (!found_merge_log && !strcmp("merge.summary", key))
+		merge_summary = git_config_bool(key, value);
+	return 0;
+}
+
+struct list {
+	char **list;
+	void **payload;
+	unsigned nr, alloc;
+};
+
+static void append_to_list(struct list *list, char *value, void *payload)
+{
+	if (list->nr == list->alloc) {
+		list->alloc += 32;
+		list->list = xrealloc(list->list, sizeof(char *) * list->alloc);
+		list->payload = xrealloc(list->payload,
+				sizeof(char *) * list->alloc);
+	}
+	list->payload[list->nr] = payload;
+	list->list[list->nr++] = value;
+}
+
+static int find_in_list(struct list *list, char *value)
+{
+	int i;
+
+	for (i = 0; i < list->nr; i++)
+		if (!strcmp(list->list[i], value))
+			return i;
+
+	return -1;
+}
+
+static void free_list(struct list *list)
+{
+	int i;
+
+	if (list->alloc == 0)
+		return;
+
+	for (i = 0; i < list->nr; i++) {
+		free(list->list[i]);
+		free(list->payload[i]);
+	}
+	free(list->list);
+	free(list->payload);
+	list->nr = list->alloc = 0;
+}
+
+struct src_data {
+	struct list branch, tag, r_branch, generic;
+	int head_status;
+};
+
+static struct list srcs = { NULL, NULL, 0, 0};
+static struct list origins = { NULL, NULL, 0, 0};
+
+static int handle_line(char *line)
+{
+	int i, len = strlen(line);
+	unsigned char *sha1;
+	char *src, *origin;
+	struct src_data *src_data;
+	int pulling_head = 0;
+
+	if (len < 43 || line[40] != '\t')
+		return 1;
+
+	if (!prefixcmp(line + 41, "not-for-merge"))
+		return 0;
+
+	if (line[41] != '\t')
+		return 2;
+
+	line[40] = 0;
+	sha1 = xmalloc(20);
+	i = get_sha1(line, sha1);
+	line[40] = '\t';
+	if (i)
+		return 3;
+
+	if (line[len - 1] == '\n')
+		line[len - 1] = 0;
+	line += 42;
+
+	src = strstr(line, " of ");
+	if (src) {
+		*src = 0;
+		src += 4;
+		pulling_head = 0;
+	} else {
+		src = line;
+		pulling_head = 1;
+	}
+
+	i = find_in_list(&srcs, src);
+	if (i < 0) {
+		i = srcs.nr;
+		append_to_list(&srcs, xstrdup(src),
+				xcalloc(1, sizeof(struct src_data)));
+	}
+	src_data = srcs.payload[i];
+
+	if (pulling_head) {
+		origin = xstrdup(src);
+		src_data->head_status |= 1;
+	} else if (!prefixcmp(line, "branch ")) {
+		origin = xstrdup(line + 7);
+		append_to_list(&src_data->branch, origin, NULL);
+		src_data->head_status |= 2;
+	} else if (!prefixcmp(line, "tag ")) {
+		origin = line;
+		append_to_list(&src_data->tag, xstrdup(origin + 4), NULL);
+		src_data->head_status |= 2;
+	} else if (!prefixcmp(line, "remote branch ")) {
+		origin = xstrdup(line + 14);
+		append_to_list(&src_data->r_branch, origin, NULL);
+		src_data->head_status |= 2;
+	} else {
+		origin = xstrdup(src);
+		append_to_list(&src_data->generic, xstrdup(line), NULL);
+		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 = xstrdup(origin);
+		}
+	} else {
+		char *new_origin = xmalloc(strlen(origin) + strlen(src) + 5);
+		sprintf(new_origin, "%s of %s", origin, src);
+		origin = new_origin;
+	}
+	append_to_list(&origins, origin, sha1);
+	return 0;
+}
+
+static void print_joined(const char *singular, const char *plural,
+		struct list *list, struct strbuf *out)
+{
+	if (list->nr == 0)
+		return;
+	if (list->nr == 1) {
+		strbuf_addf(out, "%s%s", singular, list->list[0]);
+	} else {
+		int i;
+		strbuf_addstr(out, plural);
+		for (i = 0; i < list->nr - 1; i++)
+			strbuf_addf(out, "%s%s", i > 0 ? ", " : "", list->list[i]);
+		strbuf_addf(out, " and %s", list->list[list->nr - 1]);
+	}
+}
+
+static void shortlog(const char *name, unsigned char *sha1,
+		struct commit *head, struct rev_info *rev, int limit,
+		struct strbuf *out)
+{
+	int i, count = 0;
+	struct commit *commit;
+	struct object *branch;
+	struct list subjects = { NULL, NULL, 0, 0 };
+	int flags = UNINTERESTING | TREESAME | SEEN | SHOWN | ADDED;
+
+	branch = deref_tag(parse_object(sha1), sha1_to_hex(sha1), 40);
+	if (!branch || branch->type != OBJ_COMMIT)
+		return;
+
+	setup_revisions(0, NULL, rev, NULL);
+	rev->ignore_merges = 1;
+	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) {
+		char *oneline, *bol, *eol;
+
+		/* ignore merges */
+		if (commit->parents && commit->parents->next)
+			continue;
+
+		count++;
+		if (subjects.nr > limit)
+			continue;
+
+		bol = strstr(commit->buffer, "\n\n");
+		if (bol) {
+			unsigned char c;
+			do {
+				c = *++bol;
+			} while (isspace(c));
+			if (!c)
+				bol = NULL;
+		}
+
+		if (!bol) {
+			append_to_list(&subjects, xstrdup(sha1_to_hex(
+							commit->object.sha1)),
+					NULL);
+			continue;
+		}
+
+		eol = strchr(bol, '\n');
+		if (eol) {
+			oneline = xmemdupz(bol, eol - bol);
+		} else {
+			oneline = xstrdup(bol);
+		}
+		append_to_list(&subjects, oneline, NULL);
+	}
+
+	if (count > limit)
+		strbuf_addf(out, "\n* %s: (%d commits)\n", name, count);
+	else
+		strbuf_addf(out, "\n* %s:\n", name);
+
+	for (i = 0; i < subjects.nr; i++)
+		if (i >= limit)
+			strbuf_addf(out, "  ...\n");
+		else
+			strbuf_addf(out, "  %s\n", subjects.list[i]);
+
+	clear_commit_marks((struct commit *)branch, flags);
+	clear_commit_marks(head, flags);
+	free_commit_list(rev->commits);
+	rev->commits = NULL;
+	rev->pending.nr = 0;
+
+	free_list(&subjects);
+}
+
+int fmt_merge_msg(int merge_summary, struct strbuf *in, struct strbuf *out) {
+	int limit = 20, i = 0, pos = 0;
+	char line[1024];
+	char *p = line, *sep = "";
+	unsigned char head_sha1[20];
+	const char *current_branch;
+
+	/* get current branch */
+	current_branch = resolve_ref("HEAD", head_sha1, 1, NULL);
+	if (!current_branch)
+		die("No current branch");
+	if (!prefixcmp(current_branch, "refs/heads/"))
+		current_branch += 11;
+
+	/* 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))
+			die ("Error in line %d: %.*s", i, len, p);
+	}
+
+	strbuf_addstr(out, "Merge ");
+	for (i = 0; i < srcs.nr; i++) {
+		struct src_data *src_data = srcs.payload[i];
+		const char *subsep = "";
+
+		strbuf_addstr(out, sep);
+		sep = "; ";
+
+		if (src_data->head_status == 1) {
+			strbuf_addstr(out, srcs.list[i]);
+			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 branch ", "remote 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.list[i]))
+			strbuf_addf(out, " of %s", srcs.list[i]);
+	}
+
+	if (!strcmp("master", current_branch))
+		strbuf_addch(out, '\n');
+	else
+		strbuf_addf(out, " into %s\n", current_branch);
+
+	if (merge_summary) {
+		struct commit *head;
+		struct rev_info rev;
+
+		head = lookup_commit(head_sha1);
+		init_revisions(&rev, NULL);
+		rev.commit_format = CMIT_FMT_ONELINE;
+		rev.ignore_merges = 1;
+		rev.limited = 1;
+
+		for (i = 0; i < origins.nr; i++)
+			shortlog(origins.list[i], origins.payload[i],
+					head, &rev, limit, out);
+	}
+	return 0;
+}
+
+int cmd_fmt_merge_msg(int argc, const char **argv, const char *prefix)
+{
+	const char *inpath = NULL;
+	struct option options[] = {
+		OPT_BOOLEAN(0, "log",     &merge_summary, "populate log with the shortlog"),
+		OPT_BOOLEAN(0, "summary", &merge_summary, "alias for --log"),
+		OPT_STRING('F', "file",   &inpath, "file", "file to read from"),
+		OPT_END()
+	};
+
+	FILE *in = stdin;
+	struct strbuf input = STRBUF_INIT, output = STRBUF_INIT;
+	int ret;
+
+	git_config(fmt_merge_msg_config, NULL);
+	argc = parse_options(argc, argv, options, fmt_merge_msg_usage, 0);
+	if (argc > 0)
+		usage_with_options(fmt_merge_msg_usage, options);
+
+	if (inpath && strcmp(inpath, "-")) {
+		in = fopen(inpath, "r");
+		if (!in)
+			die("cannot open %s", inpath);
+	}
+
+	if (strbuf_read(&input, fileno(in), 0) < 0)
+		die("could not read input file %s", strerror(errno));
+
+	ret = fmt_merge_msg(merge_summary, &input, &output);
+	if (ret)
+		return ret;
+	write_in_full(STDOUT_FILENO, output.buf, output.len);
+	return 0;
+}