Merge branch 'db/cover-letter'

* db/cover-letter:
  Improve collection of information for format-patch --cover-letter
  Add API access to shortlog
  t4014: Replace sed's non-standard 'Q' by standard 'q'
  Support a --cc=<email> option in format-patch
  Combine To: and Cc: headers
  Fix format.headers not ending with a newline
  Add tests for extra headers in format-patch
  Add a --cover-letter option to format-patch
  Export some email and pretty-printing functions
  Improve message-id generation flow control for format-patch
  Add more tests for format-patch

Conflicts:

	builtin-log.c
	builtin-shortlog.c
	pretty.c

12 files changed, 699 insertions, 234 deletions

diff --git a/Documentation/git-format-patch.txt b/Documentation/git-format-patch.txt
index 651efe6ca..b5207b760 100644
--- a/Documentation/git-format-patch.txt
+++ b/Documentation/git-format-patch.txt
@@ -10,13 +10,15 @@ SYNOPSIS
 --------
 [verse]
 'git-format-patch' [-k] [-o <dir> | --stdout] [--thread]
-                   [--attach[=<boundary>] | --inline[=<boundary>]]
-                   [-s | --signoff] [<common diff options>]
-                   [-n | --numbered | -N | --no-numbered]
-                   [--start-number <n>] [--numbered-files]
-                   [--in-reply-to=Message-Id] [--suffix=.<sfx>]
-                   [--ignore-if-in-upstream]
-                   [--subject-prefix=Subject-Prefix]
+		   [--attach[=<boundary>] | --inline[=<boundary>]]
+		   [-s | --signoff] [<common diff options>]
+		   [-n | --numbered | -N | --no-numbered]
+		   [--start-number <n>] [--numbered-files]
+		   [--in-reply-to=Message-Id] [--suffix=.<sfx>]
+		   [--ignore-if-in-upstream]
+		   [--subject-prefix=Subject-Prefix]
+		   [--cc=<email>]
+		   [--cover-letter]
 		   [ <since> | <revision range> ]
 
 DESCRIPTION
@@ -135,6 +137,15 @@ include::diff-options.txt[]
 	allows for useful naming of a patch series, and can be
 	combined with the --numbered option.
 
+--cc=<email>::
+	Add a "Cc:" header to the email headers. This is in addition
+	to any configured headers, and may be used multiple times.
+
+--cover-letter::
+	Generate a cover letter template.  You still have to fill in
+	a description, but the shortlog and the diffstat will be
+	generated for you.
+
 --suffix=.<sfx>::
 	Instead of using `.patch` as the suffix for generated
 	filenames, use specified suffix.  A common alternative is
diff --git a/builtin-log.c b/builtin-log.c
index c67d63cb1..3209ea5c6 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -15,6 +15,8 @@
 #include "reflog-walk.h"
 #include "patch-ids.h"
 #include "refs.h"
+#include "run-command.h"
+#include "shortlog.h"
 
 static int default_show_root = 1;
 static const char *fmt_patch_subject_prefix = "PATCH";
@@ -428,24 +430,47 @@ static int istitlechar(char c)
 		(c >= '0' && c <= '9') || c == '.' || c == '_';
 }
 
-static char *extra_headers = NULL;
-static int extra_headers_size = 0;
 static const char *fmt_patch_suffix = ".patch";
 static int numbered = 0;
 static int auto_number = 0;
 
+static char **extra_hdr;
+static int extra_hdr_nr;
+static int extra_hdr_alloc;
+
+static char **extra_to;
+static int extra_to_nr;
+static int extra_to_alloc;
+
+static char **extra_cc;
+static int extra_cc_nr;
+static int extra_cc_alloc;
+
+static void add_header(const char *value)
+{
+	int len = strlen(value);
+	while (value[len - 1] == '\n')
+		len--;
+	if (!strncasecmp(value, "to: ", 4)) {
+		ALLOC_GROW(extra_to, extra_to_nr + 1, extra_to_alloc);
+		extra_to[extra_to_nr++] = xstrndup(value + 4, len - 4);
+		return;
+	}
+	if (!strncasecmp(value, "cc: ", 4)) {
+		ALLOC_GROW(extra_cc, extra_cc_nr + 1, extra_cc_alloc);
+		extra_cc[extra_cc_nr++] = xstrndup(value + 4, len - 4);
+		return;
+	}
+	ALLOC_GROW(extra_hdr, extra_hdr_nr + 1, extra_hdr_alloc);
+	extra_hdr[extra_hdr_nr++] = xstrndup(value, len);
+}
+
 static int git_format_config(const char *var, const char *value)
 {
 	if (!strcmp(var, "format.headers")) {
-		int len;
-
 		if (!value)
 			die("format.headers without value");
-		len = strlen(value);
-		extra_headers_size += len + 1;
-		extra_headers = xrealloc(extra_headers, extra_headers_size);
-		extra_headers[extra_headers_size - len - 1] = 0;
-		strcat(extra_headers, value);
+		add_header(value);
 		return 0;
 	}
 	if (!strcmp(var, "format.suffix")) {
@@ -470,74 +495,81 @@ static int git_format_config(const char *var, const char *value)
 }
 
 
+static const char *get_oneline_for_filename(struct commit *commit,
+					    int keep_subject)
+{
+	static char filename[PATH_MAX];
+	char *sol;
+	int len = 0;
+	int suffix_len = strlen(fmt_patch_suffix) + 1;
+
+	sol = strstr(commit->buffer, "\n\n");
+	if (!sol)
+		filename[0] = '\0';
+	else {
+		int j, space = 0;
+
+		sol += 2;
+		/* strip [PATCH] or [PATCH blabla] */
+		if (!keep_subject && !prefixcmp(sol, "[PATCH")) {
+			char *eos = strchr(sol + 6, ']');
+			if (eos) {
+				while (isspace(*eos))
+					eos++;
+				sol = eos;
+			}
+		}
+
+		for (j = 0;
+		     j < FORMAT_PATCH_NAME_MAX - suffix_len - 5 &&
+			     len < sizeof(filename) - suffix_len &&
+			     sol[j] && sol[j] != '\n';
+		     j++) {
+			if (istitlechar(sol[j])) {
+				if (space) {
+					filename[len++] = '-';
+					space = 0;
+				}
+				filename[len++] = sol[j];
+				if (sol[j] == '.')
+					while (sol[j + 1] == '.')
+						j++;
+			} else
+				space = 1;
+		}
+		while (filename[len - 1] == '.'
+		       || filename[len - 1] == '-')
+			len--;
+		filename[len] = '\0';
+	}
+	return filename;
+}
+
 static FILE *realstdout = NULL;
 static const char *output_directory = NULL;
 
-static int reopen_stdout(struct commit *commit, int nr, int keep_subject,
-			 int numbered_files)
+static int reopen_stdout(const char *oneline, int nr, int total)
 {
 	char filename[PATH_MAX];
-	char *sol;
 	int len = 0;
 	int suffix_len = strlen(fmt_patch_suffix) + 1;
 
 	if (output_directory) {
-		if (strlen(output_directory) >=
+		len = snprintf(filename, sizeof(filename), "%s",
+				output_directory);
+		if (len >=
 		    sizeof(filename) - FORMAT_PATCH_NAME_MAX - suffix_len)
 			return error("name of output directory is too long");
-		strlcpy(filename, output_directory, sizeof(filename) - suffix_len);
-		len = strlen(filename);
 		if (filename[len - 1] != '/')
 			filename[len++] = '/';
 	}
 
-	if (numbered_files) {
-		sprintf(filename + len, "%d", nr);
-		len = strlen(filename);
-
-	} else {
-		sprintf(filename + len, "%04d", nr);
-		len = strlen(filename);
-
-		sol = strstr(commit->buffer, "\n\n");
-		if (sol) {
-			int j, space = 1;
-
-			sol += 2;
-			/* strip [PATCH] or [PATCH blabla] */
-			if (!keep_subject && !prefixcmp(sol, "[PATCH")) {
-				char *eos = strchr(sol + 6, ']');
-				if (eos) {
-					while (isspace(*eos))
-						eos++;
-					sol = eos;
-				}
-			}
-
-			for (j = 0;
-			     j < FORMAT_PATCH_NAME_MAX - suffix_len - 5 &&
-				     len < sizeof(filename) - suffix_len &&
-				     sol[j] && sol[j] != '\n';
-			     j++) {
-				if (istitlechar(sol[j])) {
-					if (space) {
-						filename[len++] = '-';
-						space = 0;
-					}
-					filename[len++] = sol[j];
-					if (sol[j] == '.')
-						while (sol[j + 1] == '.')
-							j++;
-				} else
-					space = 1;
-			}
-			while (filename[len - 1] == '.'
-			       || filename[len - 1] == '-')
-				len--;
-			filename[len] = 0;
-		}
-		if (len + suffix_len >= sizeof(filename))
-			return error("Patch pathname too long");
+	if (!oneline)
+		len += sprintf(filename + len, "%d", nr);
+	else {
+		len += sprintf(filename + len, "%04d-", nr);
+		len += snprintf(filename + len, sizeof(filename) - len - 1
+				- suffix_len, "%s", oneline);
 		strcpy(filename + len, fmt_patch_suffix);
 	}
 
@@ -594,16 +626,89 @@ static void get_patch_ids(struct rev_info *rev, struct patch_ids *ids, const cha
 	o2->flags = flags2;
 }
 
-static void gen_message_id(char *dest, unsigned int length, char *base)
+static void gen_message_id(struct rev_info *info, char *base)
 {
 	const char *committer = git_committer_info(IDENT_WARN_ON_NO_NAME);
 	const char *email_start = strrchr(committer, '<');
 	const char *email_end = strrchr(committer, '>');
-	if(!email_start || !email_end || email_start > email_end - 1)
+	struct strbuf buf;
+	if (!email_start || !email_end || email_start > email_end - 1)
 		die("Could not extract email from committer identity.");
-	snprintf(dest, length, "%s.%lu.git.%.*s", base,
-		 (unsigned long) time(NULL),
-		 (int)(email_end - email_start - 1), email_start + 1);
+	strbuf_init(&buf, 0);
+	strbuf_addf(&buf, "%s.%lu.git.%.*s", base,
+		    (unsigned long) time(NULL),
+		    (int)(email_end - email_start - 1), email_start + 1);
+	info->message_id = strbuf_detach(&buf, NULL);
+}
+
+static void make_cover_letter(struct rev_info *rev, int use_stdout,
+			      int numbered, int numbered_files,
+			      struct commit *origin,
+			      int nr, struct commit **list, struct commit *head)
+{
+	const char *committer;
+	const char *origin_sha1, *head_sha1;
+	const char *argv[7];
+	const char *subject_start = NULL;
+	const char *body = "*** SUBJECT HERE ***\n\n*** BLURB HERE ***\n";
+	const char *msg;
+	const char *extra_headers = rev->extra_headers;
+	struct shortlog log;
+	struct strbuf sb;
+	int i;
+	const char *encoding = "utf-8";
+
+	if (rev->commit_format != CMIT_FMT_EMAIL)
+		die("Cover letter needs email format");
+
+	if (!use_stdout && reopen_stdout(numbered_files ?
+				NULL : "cover-letter", 0, rev->total))
+		return;
+
+	head_sha1 = sha1_to_hex(head->object.sha1);
+
+	log_write_email_headers(rev, head_sha1, &subject_start, &extra_headers);
+
+	committer = git_committer_info(0);
+
+	msg = body;
+	strbuf_init(&sb, 0);
+	pp_user_info(NULL, CMIT_FMT_EMAIL, &sb, committer, DATE_RFC2822,
+		     encoding);
+	pp_title_line(CMIT_FMT_EMAIL, &msg, &sb, subject_start, extra_headers,
+		      encoding, 0);
+	pp_remainder(CMIT_FMT_EMAIL, &msg, &sb, 0);
+	printf("%s\n", sb.buf);
+
+	strbuf_release(&sb);
+
+	shortlog_init(&log);
+	for (i = 0; i < nr; i++)
+		shortlog_add_commit(&log, list[i]);
+
+	shortlog_output(&log);
+
+	/*
+	 * We can only do diffstat with a unique reference point
+	 */
+	if (!origin)
+		return;
+
+	origin_sha1 = sha1_to_hex(origin->object.sha1);
+
+	argv[0] = "diff";
+	argv[1] = "--stat";
+	argv[2] = "--summary";
+	argv[3] = head_sha1;
+	argv[4] = "--not";
+	argv[5] = origin_sha1;
+	argv[6] = "--";
+	argv[7] = NULL;
+	fflush(stdout);
+	run_command_v_opt(argv, RUN_GIT_CMD);
+
+	fflush(stdout);
+	printf("\n");
 }
 
 static const char *clean_message_id(const char *msg_id)
@@ -641,11 +746,13 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	int subject_prefix = 0;
 	int ignore_if_in_upstream = 0;
 	int thread = 0;
+	int cover_letter = 0;
+	int boundary_count = 0;
+	struct commit *origin = NULL, *head = NULL;
 	const char *in_reply_to = NULL;
 	struct patch_ids ids;
 	char *add_signoff = NULL;
-	char message_id[1024];
-	char ref_message_id[1024];
+	struct strbuf buf;
 
 	git_config(git_format_config);
 	init_revisions(&rev, prefix);
@@ -658,7 +765,6 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 	DIFF_OPT_SET(&rev.diffopt, RECURSIVE);
 
 	rev.subject_prefix = fmt_patch_subject_prefix;
-	rev.extra_headers = extra_headers;
 
 	/*
 	 * Parse the arguments before setup_revisions(), or something
@@ -686,6 +792,10 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 				die("Need a number for --start-number");
 			start_number = strtol(argv[i], NULL, 10);
 		}
+		else if (!prefixcmp(argv[i], "--cc=")) {
+			ALLOC_GROW(extra_cc, extra_cc_nr + 1, extra_cc_alloc);
+			extra_cc[extra_cc_nr++] = xstrdup(argv[i] + 5);
+		}
 		else if (!strcmp(argv[i], "-k") ||
 				!strcmp(argv[i], "--keep-subject")) {
 			keep_subject = 1;
@@ -742,11 +852,44 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 			rev.subject_prefix = argv[i] + 17;
 		} else if (!prefixcmp(argv[i], "--suffix="))
 			fmt_patch_suffix = argv[i] + 9;
+		else if (!strcmp(argv[i], "--cover-letter"))
+			cover_letter = 1;
 		else
 			argv[j++] = argv[i];
 	}
 	argc = j;
 
+	strbuf_init(&buf, 0);
+
+	for (i = 0; i < extra_hdr_nr; i++) {
+		strbuf_addstr(&buf, extra_hdr[i]);
+		strbuf_addch(&buf, '\n');
+	}
+
+	if (extra_to_nr)
+		strbuf_addstr(&buf, "To: ");
+	for (i = 0; i < extra_to_nr; i++) {
+		if (i)
+			strbuf_addstr(&buf, "    ");
+		strbuf_addstr(&buf, extra_to[i]);
+		if (i + 1 < extra_to_nr)
+			strbuf_addch(&buf, ',');
+		strbuf_addch(&buf, '\n');
+	}
+
+	if (extra_cc_nr)
+		strbuf_addstr(&buf, "Cc: ");
+	for (i = 0; i < extra_cc_nr; i++) {
+		if (i)
+			strbuf_addstr(&buf, "    ");
+		strbuf_addstr(&buf, extra_cc[i]);
+		if (i + 1 < extra_cc_nr)
+			strbuf_addch(&buf, ',');
+		strbuf_addch(&buf, '\n');
+	}
+
+	rev.extra_headers = strbuf_detach(&buf, 0);
+
 	if (start_number < 0)
 		start_number = 1;
 	if (numbered && keep_subject)
@@ -793,6 +936,18 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		 * get_revision() to do the usual traversal.
 		 */
 	}
+	if (cover_letter) {
+		/* remember the range */
+		int i;
+		for (i = 0; i < rev.pending.nr; i++) {
+			struct object *o = rev.pending.objects[i].item;
+			if (!(o->flags & UNINTERESTING))
+				head = (struct commit *)o;
+		}
+		/* We can't generate a cover letter without any patches */
+		if (!head)
+			return 0;
+	}
 
 	if (ignore_if_in_upstream)
 		get_patch_ids(&rev, &ids, prefix);
@@ -802,7 +957,15 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 
 	if (prepare_revision_walk(&rev))
 		die("revision walk setup failed");
+	rev.boundary = 1;
 	while ((commit = get_revision(&rev)) != NULL) {
+		if (commit->object.flags & BOUNDARY) {
+			fprintf(stderr, "Boundary %s\n", sha1_to_hex(commit->object.sha1));
+			boundary_count++;
+			origin = (boundary_count == 1) ? commit : NULL;
+			continue;
+		}
+
 		/* ignore merges */
 		if (commit->parents && commit->parents->next)
 			continue;
@@ -820,29 +983,42 @@ int cmd_format_patch(int argc, const char **argv, const char *prefix)
 		numbered = 1;
 	if (numbered)
 		rev.total = total + start_number - 1;
-	rev.add_signoff = add_signoff;
 	if (in_reply_to)
 		rev.ref_message_id = clean_message_id(in_reply_to);
+	if (cover_letter) {
+		if (thread)
+			gen_message_id(&rev, "cover");
+		make_cover_letter(&rev, use_stdout, numbered, numbered_files,
+				  origin, nr, list, head);
+		total++;
+		start_number--;
+	}
+	rev.add_signoff = add_signoff;
 	while (0 <= --nr) {
 		int shown;
 		commit = list[nr];
 		rev.nr = total - nr + (start_number - 1);
 		/* Make the second and subsequent mails replies to the first */
 		if (thread) {
-			if (nr == (total - 2)) {
-				strncpy(ref_message_id, message_id,
-					sizeof(ref_message_id));
-				ref_message_id[sizeof(ref_message_id)-1]='\0';
-				rev.ref_message_id = ref_message_id;
+			/* Have we already had a message ID? */
+			if (rev.message_id) {
+				/*
+				 * If we've got the ID to be a reply
+				 * to, discard the current ID;
+				 * otherwise, make everything a reply
+				 * to that.
+				 */
+				if (rev.ref_message_id)
+					free(rev.message_id);
+				else
+					rev.ref_message_id = rev.message_id;
 			}
-			gen_message_id(message_id, sizeof(message_id),
-				       sha1_to_hex(commit->object.sha1));
-			rev.message_id = message_id;
+			gen_message_id(&rev, sha1_to_hex(commit->object.sha1));
 		}
-		if (!use_stdout)
-			if (reopen_stdout(commit, rev.nr, keep_subject,
-					  numbered_files))
-				die("Failed to create output files");
+		if (!use_stdout && reopen_stdout(numbered_files ? NULL :
+				get_oneline_for_filename(commit, keep_subject),
+				rev.nr, rev.total))
+			die("Failed to create output files");
 		shown = log_tree_commit(&rev, commit);
 		free(commit->buffer);
 		commit->buffer = NULL;
diff --git a/builtin-shortlog.c b/builtin-shortlog.c
index 0055a57ae..af31abaaf 100644
--- a/builtin-shortlog.c
+++ b/builtin-shortlog.c
@@ -6,13 +6,11 @@
 #include "revision.h"
 #include "utf8.h"
 #include "mailmap.h"
+#include "shortlog.h"
 
 static const char shortlog_usage[] =
 "git-shortlog [-n] [-s] [-e] [<commit-id>... ]";
 
-static char *common_repo_prefix;
-static int email;
-
 static int compare_by_number(const void *a1, const void *a2)
 {
 	const struct path_list_item *i1 = a1, *i2 = a2;
@@ -26,13 +24,11 @@ static int compare_by_number(const void *a1, const void *a2)
 		return -1;
 }
 
-static struct path_list mailmap = {NULL, 0, 0, 0};
-
-static void insert_one_record(struct path_list *list,
+static void insert_one_record(struct shortlog *log,
 			      const char *author,
 			      const char *oneline)
 {
-	const char *dot3 = common_repo_prefix;
+	const char *dot3 = log->common_repo_prefix;
 	char *buffer, *p;
 	struct path_list_item *item;
 	struct path_list *onelines;
@@ -47,7 +43,7 @@ static void insert_one_record(struct path_list *list,
 	eoemail = strchr(boemail, '>');
 	if (!eoemail)
 		return;
-	if (!map_email(&mailmap, boemail+1, namebuf, sizeof(namebuf))) {
+	if (!map_email(&log->mailmap, boemail+1, namebuf, sizeof(namebuf))) {
 		while (author < boemail && isspace(*author))
 			author++;
 		for (len = 0;
@@ -61,14 +57,14 @@ static void insert_one_record(struct path_list *list,
 	else
 		len = strlen(namebuf);
 
-	if (email) {
+	if (log->email) {
 		size_t room = sizeof(namebuf) - len - 1;
 		int maillen = eoemail - boemail + 1;
 		snprintf(namebuf + len, room, " %.*s", maillen, boemail);
 	}
 
 	buffer = xstrdup(namebuf);
-	item = path_list_insert(buffer, list);
+	item = path_list_insert(buffer, &log->list);
 	if (item->util == NULL)
 		item->util = xcalloc(1, sizeof(struct path_list));
 	else
@@ -114,7 +110,7 @@ static void insert_one_record(struct path_list *list,
 	onelines->items[onelines->nr++].path = buffer;
 }
 
-static void read_from_stdin(struct path_list *list)
+static void read_from_stdin(struct shortlog *log)
 {
 	char author[1024], oneline[1024];
 
@@ -128,39 +124,43 @@ static void read_from_stdin(struct path_list *list)
 		while (fgets(oneline, sizeof(oneline), stdin) &&
 		       oneline[0] == '\n')
 			; /* discard blanks */
-		insert_one_record(list, author + 8, oneline);
+		insert_one_record(log, author + 8, oneline);
 	}
 }
 
-static void get_from_rev(struct rev_info *rev, struct path_list *list)
+void shortlog_add_commit(struct shortlog *log, struct commit *commit)
 {
-	struct commit *commit;
-
-	if (prepare_revision_walk(rev))
-		die("revision walk setup failed");
-	while ((commit = get_revision(rev)) != NULL) {
-		const char *author = NULL, *buffer;
+	const char *author = NULL, *buffer;
 
-		buffer = commit->buffer;
-		while (*buffer && *buffer != '\n') {
-			const char *eol = strchr(buffer, '\n');
+	buffer = commit->buffer;
+	while (*buffer && *buffer != '\n') {
+		const char *eol = strchr(buffer, '\n');
 
-			if (eol == NULL)
-				eol = buffer + strlen(buffer);
-			else
-				eol++;
+		if (eol == NULL)
+			eol = buffer + strlen(buffer);
+		else
+			eol++;
 
-			if (!prefixcmp(buffer, "author "))
-				author = buffer + 7;
-			buffer = eol;
-		}
-		if (!author)
-			die("Missing author: %s",
-			    sha1_to_hex(commit->object.sha1));
-		if (*buffer)
-			buffer++;
-		insert_one_record(list, author, !*buffer ? "<none>" : buffer);
+		if (!prefixcmp(buffer, "author "))
+			author = buffer + 7;
+		buffer = eol;
 	}
+	if (!author)
+		die("Missing author: %s",
+		    sha1_to_hex(commit->object.sha1));
+	if (*buffer)
+		buffer++;
+	insert_one_record(log, author, !*buffer ? "<none>" : buffer);
+}
+
+static void get_from_rev(struct rev_info *rev, struct shortlog *log)
+{
+	struct commit *commit;
+
+	if (prepare_revision_walk(rev))
+		die("revision walk setup failed");
+	while ((commit = get_revision(rev)) != NULL)
+		shortlog_add_commit(log, commit);
 }
 
 static int parse_uint(char const **arg, int comma)
@@ -212,29 +212,38 @@ static void parse_wrap_args(const char *arg, int *in1, int *in2, int *wrap)
 		die(wrap_arg_usage);
 }
 
+void shortlog_init(struct shortlog *log)
+{
+	memset(log, 0, sizeof(*log));
+
+	read_mailmap(&log->mailmap, ".mailmap", &log->common_repo_prefix);
+
+	log->list.strdup_paths = 1;
+	log->wrap = DEFAULT_WRAPLEN;
+	log->in1 = DEFAULT_INDENT1;
+	log->in2 = DEFAULT_INDENT2;
+}
+
 int cmd_shortlog(int argc, const char **argv, const char *prefix)
 {
+	struct shortlog log;
 	struct rev_info rev;
-	struct path_list list = { NULL, 0, 0, 1 };
-	int i, j, sort_by_number = 0, summary = 0;
-	int wrap_lines = 0;
-	int wrap = DEFAULT_WRAPLEN;
-	int in1 = DEFAULT_INDENT1;
-	int in2 = DEFAULT_INDENT2;
+
+	shortlog_init(&log);
 
 	/* since -n is a shadowed rev argument, parse our args first */
 	while (argc > 1) {
 		if (!strcmp(argv[1], "-n") || !strcmp(argv[1], "--numbered"))
-			sort_by_number = 1;
+			log.sort_by_number = 1;
 		else if (!strcmp(argv[1], "-s") ||
 				!strcmp(argv[1], "--summary"))
-			summary = 1;
+			log.summary = 1;
 		else if (!strcmp(argv[1], "-e") ||
 			 !strcmp(argv[1], "--email"))
-			email = 1;
+			log.email = 1;
 		else if (!prefixcmp(argv[1], "-w")) {
-			wrap_lines = 1;
-			parse_wrap_args(argv[1], &in1, &in2, &wrap);
+			log.wrap_lines = 1;
+			parse_wrap_args(argv[1], &log.in1, &log.in2, &log.wrap);
 		}
 		else if (!strcmp(argv[1], "-h") || !strcmp(argv[1], "--help"))
 			usage(shortlog_usage);
@@ -248,34 +257,38 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 	if (argc > 1)
 		die ("unrecognized argument: %s", argv[1]);
 
-	read_mailmap(&mailmap, ".mailmap", &common_repo_prefix);
-
 	/* assume HEAD if from a tty */
 	if (!rev.pending.nr && isatty(0))
 		add_head_to_pending(&rev);
 	if (rev.pending.nr == 0) {
-		read_from_stdin(&list);
+		read_from_stdin(&log);
 	}
 	else
-		get_from_rev(&rev, &list);
+		get_from_rev(&rev, &log);
 
-	if (sort_by_number)
-		qsort(list.items, list.nr, sizeof(struct path_list_item),
-			compare_by_number);
+	shortlog_output(&log);
+	return 0;
+}
 
-	for (i = 0; i < list.nr; i++) {
-		struct path_list *onelines = list.items[i].util;
+void shortlog_output(struct shortlog *log)
+{
+	int i, j;
+	if (log->sort_by_number)
+		qsort(log->list.items, log->list.nr, sizeof(struct path_list_item),
+			compare_by_number);
+	for (i = 0; i < log->list.nr; i++) {
+		struct path_list *onelines = log->list.items[i].util;
 
-		if (summary) {
-			printf("%6d\t%s\n", onelines->nr, list.items[i].path);
+		if (log->summary) {
+			printf("%6d\t%s\n", onelines->nr, log->list.items[i].path);
 		} else {
-			printf("%s (%d):\n", list.items[i].path, onelines->nr);
+			printf("%s (%d):\n", log->list.items[i].path, onelines->nr);
 			for (j = onelines->nr - 1; j >= 0; j--) {
 				const char *msg = onelines->items[j].path;
 
-				if (wrap_lines) {
-					int col = print_wrapped_text(msg, in1, in2, wrap);
-					if (col != wrap)
+				if (log->wrap_lines) {
+					int col = print_wrapped_text(msg, log->in1, log->in2, log->wrap);
+					if (col != log->wrap)
 						putchar('\n');
 				}
 				else
@@ -287,13 +300,11 @@ int cmd_shortlog(int argc, const char **argv, const char *prefix)
 		onelines->strdup_paths = 1;
 		path_list_clear(onelines, 1);
 		free(onelines);
-		list.items[i].util = NULL;
+		log->list.items[i].util = NULL;
 	}
 
-	list.strdup_paths = 1;
-	path_list_clear(&list, 1);
-	mailmap.strdup_paths = 1;
-	path_list_clear(&mailmap, 1);
-
-	return 0;
+	log->list.strdup_paths = 1;
+	path_list_clear(&log->list, 1);
+	log->mailmap.strdup_paths = 1;
+	path_list_clear(&log->mailmap, 1);
 }
diff --git a/commit.h b/commit.h
index 10e2b5d4c..80d65b96d 100644
--- a/commit.h
+++ b/commit.h
@@ -71,6 +71,21 @@ extern void pretty_print_commit(enum cmit_fmt fmt, const struct commit*,
                                 int abbrev, const char *subject,
                                 const char *after_subject, enum date_mode,
 				int non_ascii_present);
+void pp_user_info(const char *what, enum cmit_fmt fmt, struct strbuf *sb,
+		   const char *line, enum date_mode dmode,
+		   const char *encoding);
+void pp_title_line(enum cmit_fmt fmt,
+		   const char **msg_p,
+		   struct strbuf *sb,
+		   const char *subject,
+		   const char *after_subject,
+		   const char *encoding,
+		   int plain_non_ascii);
+void pp_remainder(enum cmit_fmt fmt,
+		  const char **msg_p,
+		  struct strbuf *sb,
+		  int indent);
+
 
 /** Removes the first commit from a list sorted by date, and adds all
  * of its parents.
diff --git a/log-tree.c b/log-tree.c
index e9ba6df9d..608f697cf 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -137,6 +137,72 @@ static int has_non_ascii(const char *s)
 	return 0;
 }
 
+void log_write_email_headers(struct rev_info *opt, const char *name,
+			     const char **subject_p, const char **extra_headers_p)
+{
+	const char *subject = NULL;
+	const char *extra_headers = opt->extra_headers;
+	if (opt->total > 0) {
+		static char buffer[64];
+		snprintf(buffer, sizeof(buffer),
+			 "Subject: [%s %0*d/%d] ",
+			 opt->subject_prefix,
+			 digits_in_number(opt->total),
+			 opt->nr, opt->total);
+		subject = buffer;
+	} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
+		static char buffer[256];
+		snprintf(buffer, sizeof(buffer),
+			 "Subject: [%s] ",
+			 opt->subject_prefix);
+		subject = buffer;
+	} else {
+		subject = "Subject: ";
+	}
+
+	printf("From %s Mon Sep 17 00:00:00 2001\n", name);
+	if (opt->message_id)
+		printf("Message-Id: <%s>\n", opt->message_id);
+	if (opt->ref_message_id)
+		printf("In-Reply-To: <%s>\nReferences: <%s>\n",
+		       opt->ref_message_id, opt->ref_message_id);
+	if (opt->mime_boundary) {
+		static char subject_buffer[1024];
+		static char buffer[1024];
+		snprintf(subject_buffer, sizeof(subject_buffer) - 1,
+			 "%s"
+			 "MIME-Version: 1.0\n"
+			 "Content-Type: multipart/mixed;"
+			 " boundary=\"%s%s\"\n"
+			 "\n"
+			 "This is a multi-part message in MIME "
+			 "format.\n"
+			 "--%s%s\n"
+			 "Content-Type: text/plain; "
+			 "charset=UTF-8; format=fixed\n"
+			 "Content-Transfer-Encoding: 8bit\n\n",
+			 extra_headers ? extra_headers : "",
+			 mime_boundary_leader, opt->mime_boundary,
+			 mime_boundary_leader, opt->mime_boundary);
+		extra_headers = subject_buffer;
+
+		snprintf(buffer, sizeof(buffer) - 1,
+			 "--%s%s\n"
+			 "Content-Type: text/x-patch;"
+			 " name=\"%s.diff\"\n"
+			 "Content-Transfer-Encoding: 8bit\n"
+			 "Content-Disposition: %s;"
+			 " filename=\"%s.diff\"\n\n",
+			 mime_boundary_leader, opt->mime_boundary,
+			 name,
+			 opt->no_inline ? "attachment" : "inline",
+			 name);
+		opt->diffopt.stat_sep = buffer;
+	}
+	*subject_p = subject;
+	*extra_headers_p = extra_headers;
+}
+
 void show_log(struct rev_info *opt, const char *sep)
 {
 	struct strbuf msgbuf;
@@ -188,64 +254,8 @@ void show_log(struct rev_info *opt, const char *sep)
 	 */
 
 	if (opt->commit_format == CMIT_FMT_EMAIL) {
-		char *sha1 = sha1_to_hex(commit->object.sha1);
-		if (opt->total > 0) {
-			static char buffer[64];
-			snprintf(buffer, sizeof(buffer),
-					"Subject: [%s %0*d/%d] ",
-					opt->subject_prefix,
-					digits_in_number(opt->total),
-					opt->nr, opt->total);
-			subject = buffer;
-		} else if (opt->total == 0 && opt->subject_prefix && *opt->subject_prefix) {
-			static char buffer[256];
-			snprintf(buffer, sizeof(buffer),
-					"Subject: [%s] ",
-					opt->subject_prefix);
-			subject = buffer;
-		} else {
-			subject = "Subject: ";
-		}
-
-		printf("From %s Mon Sep 17 00:00:00 2001\n", sha1);
-		if (opt->message_id)
-			printf("Message-Id: <%s>\n", opt->message_id);
-		if (opt->ref_message_id)
-			printf("In-Reply-To: <%s>\nReferences: <%s>\n",
-			       opt->ref_message_id, opt->ref_message_id);
-		if (opt->mime_boundary) {
-			static char subject_buffer[1024];
-			static char buffer[1024];
-			snprintf(subject_buffer, sizeof(subject_buffer) - 1,
-				 "%s"
-				 "MIME-Version: 1.0\n"
-				 "Content-Type: multipart/mixed;"
-				 " boundary=\"%s%s\"\n"
-				 "\n"
-				 "This is a multi-part message in MIME "
-				 "format.\n"
-				 "--%s%s\n"
-				 "Content-Type: text/plain; "
-				 "charset=UTF-8; format=fixed\n"
-				 "Content-Transfer-Encoding: 8bit\n\n",
-				 extra_headers ? extra_headers : "",
-				 mime_boundary_leader, opt->mime_boundary,
-				 mime_boundary_leader, opt->mime_boundary);
-			extra_headers = subject_buffer;
-
-			snprintf(buffer, sizeof(buffer) - 1,
-				 "--%s%s\n"
-				 "Content-Type: text/x-patch;"
-				 " name=\"%s.diff\"\n"
-				 "Content-Transfer-Encoding: 8bit\n"
-				 "Content-Disposition: %s;"
-				 " filename=\"%s.diff\"\n\n",
-				 mime_boundary_leader, opt->mime_boundary,
-				 sha1,
-				 opt->no_inline ? "attachment" : "inline",
-				 sha1);
-			opt->diffopt.stat_sep = buffer;
-		}
+		log_write_email_headers(opt, sha1_to_hex(commit->object.sha1),
+					&subject, &extra_headers);
 	} else if (opt->commit_format != CMIT_FMT_USERFORMAT) {
 		fputs(diff_get_color_opt(&opt->diffopt, DIFF_COMMIT), stdout);
 		if (opt->commit_format != CMIT_FMT_ONELINE)
diff --git a/log-tree.h b/log-tree.h
index b33f7cd7a..0cc9344ea 100644
--- a/log-tree.h
+++ b/log-tree.h
@@ -13,5 +13,7 @@ int log_tree_commit(struct rev_info *, struct commit *);
 int log_tree_opt_parse(struct rev_info *, const char **, int);
 void show_log(struct rev_info *opt, const char *sep);
 void show_decorations(struct commit *commit);
+void log_write_email_headers(struct rev_info *opt, const char *name,
+			     const char **subject_p, const char **extra_headers_p);
 
 #endif
diff --git a/pretty.c b/pretty.c
index 997f5837d..a5b2d8c60 100644
--- a/pretty.c
+++ b/pretty.c
@@ -110,9 +110,9 @@ needquote:
 	strbuf_addstr(sb, "?=");
 }
 
-static void add_user_info(const char *what, enum cmit_fmt fmt, struct strbuf *sb,
-			 const char *line, enum date_mode dmode,
-			 const char *encoding)
+void pp_user_info(const char *what, enum cmit_fmt fmt, struct strbuf *sb,
+		  const char *line, enum date_mode dmode,
+		  const char *encoding)
 {
 	char *date;
 	int namelen;
@@ -621,23 +621,23 @@ static void pp_header(enum cmit_fmt fmt,
 		 */
 		if (!memcmp(line, "author ", 7)) {
 			strbuf_grow(sb, linelen + 80);
-			add_user_info("Author", fmt, sb, line + 7, dmode, encoding);
+			pp_user_info("Author", fmt, sb, line + 7, dmode, encoding);
 		}
 		if (!memcmp(line, "committer ", 10) &&
 		    (fmt == CMIT_FMT_FULL || fmt == CMIT_FMT_FULLER)) {
 			strbuf_grow(sb, linelen + 80);
-			add_user_info("Commit", fmt, sb, line + 10, dmode, encoding);
+			pp_user_info("Commit", fmt, sb, line + 10, dmode, encoding);
 		}
 	}
 }
 
-static void pp_title_line(enum cmit_fmt fmt,
-			  const char **msg_p,
-			  struct strbuf *sb,
-			  const char *subject,
-			  const char *after_subject,
-			  const char *encoding,
-			  int plain_non_ascii)
+void pp_title_line(enum cmit_fmt fmt,
+		   const char **msg_p,
+		   struct strbuf *sb,
+		   const char *subject,
+		   const char *after_subject,
+		   const char *encoding,
+		   int plain_non_ascii)
 {
 	struct strbuf title;
 
@@ -686,10 +686,10 @@ static void pp_title_line(enum cmit_fmt fmt,
 	strbuf_release(&title);
 }
 
-static void pp_remainder(enum cmit_fmt fmt,
-			 const char **msg_p,
-			 struct strbuf *sb,
-			 int indent)
+void pp_remainder(enum cmit_fmt fmt,
+		  const char **msg_p,
+		  struct strbuf *sb,
+		  int indent)
 {
 	int first = 1;
 	for (;;) {
diff --git a/revision.h b/revision.h
index b5f01f830..c8b3b948e 100644
--- a/revision.h
+++ b/revision.h
@@ -75,7 +75,7 @@ struct rev_info {
 	struct log_info *loginfo;
 	int		nr, total;
 	const char	*mime_boundary;
-	const char	*message_id;
+	char		*message_id;
 	const char	*ref_message_id;
 	const char	*add_signoff;
 	const char	*extra_headers;
diff --git a/shortlog.h b/shortlog.h
new file mode 100644
index 000000000..31ff491b7
--- /dev/null
+++ b/shortlog.h
@@ -0,0 +1,26 @@
+#ifndef SHORTLOG_H
+#define SHORTLOG_H
+
+#include "path-list.h"
+
+struct shortlog {
+	struct path_list list;
+	int summary;
+	int wrap_lines;
+	int sort_by_number;
+	int wrap;
+	int in1;
+	int in2;
+
+	char *common_repo_prefix;
+	int email;
+	struct path_list mailmap;
+};
+
+void shortlog_init(struct shortlog *log);
+
+void shortlog_add_commit(struct shortlog *log, struct commit *commit);
+
+void shortlog_output(struct shortlog *log);
+
+#endif
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 9eec75422..6b4d1c52b 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -245,6 +245,7 @@ format-patch --inline --stdout initial..master
 format-patch --inline --stdout --subject-prefix=TESTCASE initial..master
 config format.subjectprefix DIFFERENT_PREFIX
 format-patch --inline --stdout initial..master^^
+format-patch --stdout --cover-letter -n initial..master^
 
 diff --abbrev initial..side
 diff -r initial..side
diff --git a/t/t4013/diff.format-patch_--stdout_--cover-letter_-n_initial..master^ b/t/t4013/diff.format-patch_--stdout_--cover-letter_-n_initial..master^
new file mode 100644
index 000000000..0151453b7
--- /dev/null
+++ b/t/t4013/diff.format-patch_--stdout_--cover-letter_-n_initial..master^
@@ -0,0 +1,100 @@
+$ git format-patch --stdout --cover-letter -n initial..master^
+From 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0 Mon Sep 17 00:00:00 2001
+From: C O Mitter <committer@example.com>
+Date: Mon, 26 Jun 2006 00:05:00 +0000
+Subject: [DIFFERENT_PREFIX 0/2] *** SUBJECT HERE ***
+
+*** BLURB HERE ***
+
+A U Thor (2):
+      Second
+      Third
+
+ dir/sub |    4 ++++
+ file0   |    3 +++
+ file1   |    3 +++
+ file2   |    3 ---
+ 4 files changed, 10 insertions(+), 3 deletions(-)
+ create mode 100644 file1
+ delete mode 100644 file2
+
+From 1bde4ae5f36c8d9abe3a0fce0c6aab3c4a12fe44 Mon Sep 17 00:00:00 2001
+From: A U Thor <author@example.com>
+Date: Mon, 26 Jun 2006 00:01:00 +0000
+Subject: [DIFFERENT_PREFIX 1/2] Second
+
+This is the second commit.
+---
+ dir/sub |    2 ++
+ file0   |    3 +++
+ file2   |    3 ---
+ 3 files changed, 5 insertions(+), 3 deletions(-)
+ delete mode 100644 file2
+
+diff --git a/dir/sub b/dir/sub
+index 35d242b..8422d40 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -1,2 +1,4 @@
+ A
+ B
++C
++D
+diff --git a/file0 b/file0
+index 01e79c3..b414108 100644
+--- a/file0
++++ b/file0
+@@ -1,3 +1,6 @@
+ 1
+ 2
+ 3
++4
++5
++6
+diff --git a/file2 b/file2
+deleted file mode 100644
+index 01e79c3..0000000
+--- a/file2
++++ /dev/null
+@@ -1,3 +0,0 @@
+-1
+-2
+-3
+-- 
+g-i-t--v-e-r-s-i-o-n
+
+
+From 9a6d4949b6b76956d9d5e26f2791ec2ceff5fdc0 Mon Sep 17 00:00:00 2001
+From: A U Thor <author@example.com>
+Date: Mon, 26 Jun 2006 00:02:00 +0000
+Subject: [DIFFERENT_PREFIX 2/2] Third
+
+---
+ dir/sub |    2 ++
+ file1   |    3 +++
+ 2 files changed, 5 insertions(+), 0 deletions(-)
+ create mode 100644 file1
+
+diff --git a/dir/sub b/dir/sub
+index 8422d40..cead32e 100644
+--- a/dir/sub
++++ b/dir/sub
+@@ -2,3 +2,5 @@ A
+ B
+ C
+ D
++E
++F
+diff --git a/file1 b/file1
+new file mode 100644
+index 0000000..b1e6722
+--- /dev/null
++++ b/file1
+@@ -0,0 +1,3 @@
++A
++B
++C
+-- 
+g-i-t--v-e-r-s-i-o-n
+
+$
diff --git a/t/t4014-format-patch.sh b/t/t4014-format-patch.sh
index 0a6fe5337..16aa99dc0 100755
--- a/t/t4014-format-patch.sh
+++ b/t/t4014-format-patch.sh
@@ -88,4 +88,117 @@ test_expect_success 'replay did not screw up the log message' '
 
 '
 
+test_expect_success 'extra headers' '
+
+	git config format.headers "To: R. E. Cipient <rcipient@example.com>
+" &&
+	git config --add format.headers "Cc: S. E. Cipient <scipient@example.com>
+" &&
+	git format-patch --stdout master..side > patch2 &&
+	sed -e "/^$/q" patch2 > hdrs2 &&
+	grep "^To: R. E. Cipient <rcipient@example.com>$" hdrs2 &&
+	grep "^Cc: S. E. Cipient <scipient@example.com>$" hdrs2
+	
+'
+
+test_expect_success 'extra headers without newlines' '
+
+	git config --replace-all format.headers "To: R. E. Cipient <rcipient@example.com>" &&
+	git config --add format.headers "Cc: S. E. Cipient <scipient@example.com>" &&
+	git format-patch --stdout master..side >patch3 &&
+	sed -e "/^$/q" patch3 > hdrs3 &&
+	grep "^To: R. E. Cipient <rcipient@example.com>$" hdrs3 &&
+	grep "^Cc: S. E. Cipient <scipient@example.com>$" hdrs3
+	
+'
+
+test_expect_success 'extra headers with multiple To:s' '
+
+	git config --replace-all format.headers "To: R. E. Cipient <rcipient@example.com>" &&
+	git config --add format.headers "To: S. E. Cipient <scipient@example.com>" &&
+	git format-patch --stdout master..side > patch4 &&
+	sed -e "/^$/q" patch4 > hdrs4 &&
+	grep "^To: R. E. Cipient <rcipient@example.com>,$" hdrs4 &&
+	grep "^ *S. E. Cipient <scipient@example.com>$" hdrs4
+'
+
+test_expect_success 'additional command line cc' '
+
+	git config --replace-all format.headers "Cc: R. E. Cipient <rcipient@example.com>" &&
+	git format-patch --cc="S. E. Cipient <scipient@example.com>" --stdout master..side | sed -e "/^$/q" >patch5 &&
+	grep "^Cc: R. E. Cipient <rcipient@example.com>,$" patch5 &&
+	grep "^ *S. E. Cipient <scipient@example.com>$" patch5
+'
+
+test_expect_success 'multiple files' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch -o patches/ master &&
+	ls patches/0001-Side-changes-1.patch patches/0002-Side-changes-2.patch patches/0003-Side-changes-3-with-n-backslash-n-in-it.patch
+'
+
+test_expect_success 'thread' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch --thread -o patches/ master &&
+	FIRST_MID=$(grep "Message-Id:" patches/0001-* | sed "s/^[^<]*\(<[^>]*>\).*$/\1/") &&
+	for i in patches/0002-* patches/0003-*
+	do
+	  grep "References: $FIRST_MID" $i &&
+	  grep "In-Reply-To: $FIRST_MID" $i
+	done
+'
+
+test_expect_success 'thread in-reply-to' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch --in-reply-to="<test.message>" --thread -o patches/ master &&
+	FIRST_MID="<test.message>" &&
+	for i in patches/*
+	do
+	  grep "References: $FIRST_MID" $i &&
+	  grep "In-Reply-To: $FIRST_MID" $i
+	done
+'
+
+test_expect_success 'thread cover-letter' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch --cover-letter --thread -o patches/ master &&
+	FIRST_MID=$(grep "Message-Id:" patches/0000-* | sed "s/^[^<]*\(<[^>]*>\).*$/\1/") &&
+	for i in patches/0001-* patches/0002-* patches/0003-* 
+	do
+	  grep "References: $FIRST_MID" $i &&
+	  grep "In-Reply-To: $FIRST_MID" $i
+	done
+'
+
+test_expect_success 'thread cover-letter in-reply-to' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	git format-patch --cover-letter --in-reply-to="<test.message>" --thread -o patches/ master &&
+	FIRST_MID="<test.message>" &&
+	for i in patches/*
+	do
+	  grep "References: $FIRST_MID" $i &&
+	  grep "In-Reply-To: $FIRST_MID" $i
+	done
+'
+
+test_expect_success 'excessive subject' '
+
+	rm -rf patches/ &&
+	git checkout side &&
+	for i in 5 6 1 2 3 A 4 B C 7 8 9 10 D E F; do echo "$i"; done >>file &&
+	git update-index file &&
+	git commit -m "This is an excessively long subject line for a message due to the habit some projects have of not having a short, one-line subject at the start of the commit message, but rather sticking a whole paragraph right at the start as the only thing in the commit message. It had better not become the filename for the patch." &&
+	git format-patch -o patches/ master..side &&
+	ls patches/0004-This-is-an-excessively-long-subject-line-for-a-messa.patch
+'
+
 test_done