1 files changed, 498 insertions, 125 deletions

diff --git a/builtin-commit.c b/builtin/commit.c
index 81371b1d26..66fdd22024 100644
--- a/builtin-commit.c
+++ b/builtin/commit.c
@@ -24,6 +24,8 @@
 #include "string-list.h"
 #include "rerere.h"
 #include "unpack-trees.h"
+#include "quote.h"
+#include "submodule.h"
 
 static const char * const builtin_commit_usage[] = {
 	"git commit [options] [--] <filepattern>...",
@@ -35,7 +37,25 @@ static const char * const builtin_status_usage[] = {
 	NULL
 };
 
-static unsigned char head_sha1[20], merge_head_sha1[20];
+static const char implicit_ident_advice[] =
+"Your name and email address were configured automatically based\n"
+"on your username and hostname. Please check that they are accurate.\n"
+"You can suppress this message by setting them explicitly:\n"
+"\n"
+"    git config --global user.name \"Your Name\"\n"
+"    git config --global user.email you@example.com\n"
+"\n"
+"If the identity used for this commit is wrong, you can fix it with:\n"
+"\n"
+"    git commit --amend --author='Your Name <you@example.com>'\n";
+
+static const char empty_amend_advice[] =
+"You asked to amend the most recent commit, but doing so would make\n"
+"it empty. You can repeat your command with --allow-empty, or you can\n"
+"remove the commit entirely with \"git reset HEAD^\".\n";
+
+static unsigned char head_sha1[20];
+
 static char *use_message_buffer;
 static const char commit_editmsg[] = "COMMIT_EDITMSG";
 static struct lock_file index_lock; /* real index */
@@ -43,7 +63,7 @@ static struct lock_file false_lock; /* used only for partial commits */
 static enum {
 	COMMIT_AS_IS = 1,
 	COMMIT_NORMAL,
-	COMMIT_PARTIAL,
+	COMMIT_PARTIAL
 } commit_style;
 
 static const char *logfile, *force_author;
@@ -51,8 +71,9 @@ static const char *template_file;
 static char *edit_message, *use_message;
 static char *author_name, *author_email, *author_date;
 static int all, edit_flag, also, interactive, only, amend, signoff;
-static int quiet, verbose, no_verify, allow_empty;
-static char *untracked_files_arg;
+static int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
+static int no_post_rewrite, allow_empty_message;
+static char *untracked_files_arg, *force_date, *ignore_submodule_arg;
 /*
  * The default commit message cleanup mode will remove the lines
  * beginning with # (shell comments) and leading and trailing
@@ -63,14 +84,23 @@ static char *untracked_files_arg;
 static enum {
 	CLEANUP_SPACE,
 	CLEANUP_NONE,
-	CLEANUP_ALL,
+	CLEANUP_ALL
 } cleanup_mode;
 static char *cleanup_arg;
 
-static int use_editor = 1, initial_commit, in_merge;
+static int use_editor = 1, initial_commit, in_merge, include_status = 1;
+static int show_ignored_in_status;
 static const char *only_include_assumed;
 static struct strbuf message;
 
+static int null_termination;
+static enum {
+	STATUS_FORMAT_LONG,
+	STATUS_FORMAT_SHORT,
+	STATUS_FORMAT_PORCELAIN
+} status_format = STATUS_FORMAT_LONG;
+static int status_show_branch;
+
 static int opt_parse_m(const struct option *opt, const char *arg, int unset)
 {
 	struct strbuf *buf = opt->value;
@@ -86,16 +116,21 @@ static int opt_parse_m(const struct option *opt, const char *arg, int unset)
 static struct option builtin_commit_options[] = {
 	OPT__QUIET(&quiet),
 	OPT__VERBOSE(&verbose),
-	OPT_GROUP("Commit message options"),
 
-	OPT_STRING('F', "file", &logfile, "FILE", "read log from file"),
+	OPT_GROUP("Commit message options"),
+	OPT_FILENAME('F', "file", &logfile, "read log from file"),
 	OPT_STRING(0, "author", &force_author, "AUTHOR", "override author for commit"),
+	OPT_STRING(0, "date", &force_date, "DATE", "override date for commit"),
 	OPT_CALLBACK('m', "message", &message, "MESSAGE", "specify commit message", opt_parse_m),
-	OPT_STRING('c', "reedit-message", &edit_message, "COMMIT", "reuse and edit message from specified commit "),
+	OPT_STRING('c', "reedit-message", &edit_message, "COMMIT", "reuse and edit message from specified commit"),
 	OPT_STRING('C', "reuse-message", &use_message, "COMMIT", "reuse message from specified commit"),
+	OPT_BOOLEAN(0, "reset-author", &renew_authorship, "the commit is authored by me now (used with -C-c/--amend)"),
 	OPT_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"),
-	OPT_STRING('t', "template", &template_file, "FILE", "use specified template file"),
+	OPT_FILENAME('t', "template", &template_file, "use specified template file"),
 	OPT_BOOLEAN('e', "edit", &edit_flag, "force edit of commit"),
+	OPT_STRING(0, "cleanup", &cleanup_arg, "default", "how to strip spaces and #comments from message"),
+	OPT_BOOLEAN(0, "status", &include_status, "include status in commit message template"),
+	/* end commit message options */
 
 	OPT_GROUP("Commit contents options"),
 	OPT_BOOLEAN('a', "all", &all, "commit all changed files"),
@@ -103,10 +138,25 @@ static struct option builtin_commit_options[] = {
 	OPT_BOOLEAN(0, "interactive", &interactive, "interactively add files"),
 	OPT_BOOLEAN('o', "only", &only, "commit only specified files"),
 	OPT_BOOLEAN('n', "no-verify", &no_verify, "bypass pre-commit hook"),
+	OPT_BOOLEAN(0, "dry-run", &dry_run, "show what would be committed"),
+	OPT_SET_INT(0, "short", &status_format, "show status concisely",
+		    STATUS_FORMAT_SHORT),
+	OPT_BOOLEAN(0, "branch", &status_show_branch, "show branch information"),
+	OPT_SET_INT(0, "porcelain", &status_format,
+		    "show porcelain output format", STATUS_FORMAT_PORCELAIN),
+	OPT_BOOLEAN('z', "null", &null_termination,
+		    "terminate entries with NUL"),
 	OPT_BOOLEAN(0, "amend", &amend, "amend previous commit"),
-	{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, "mode", "show untracked files, optional modes: all, normal, no. (Default: all)", PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
-	OPT_BOOLEAN(0, "allow-empty", &allow_empty, "ok to record an empty change"),
-	OPT_STRING(0, "cleanup", &cleanup_arg, "default", "how to strip spaces and #comments from message"),
+	OPT_BOOLEAN(0, "no-post-rewrite", &no_post_rewrite, "bypass post-rewrite hook"),
+	{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg, "mode", "show untracked files, optional modes: all, normal, no (Default: all)", PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+	/* end commit contents options */
+
+	{ OPTION_BOOLEAN, 0, "allow-empty", &allow_empty, NULL,
+	  "ok to record an empty change",
+	  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
+	{ OPTION_BOOLEAN, 0, "allow-empty-message", &allow_empty_message, NULL,
+	  "ok to record a change with an empty message",
+	  PARSE_OPT_NOARG | PARSE_OPT_HIDDEN },
 
 	OPT_END()
 };
@@ -164,11 +214,15 @@ static int list_paths(struct string_list *list, const char *with_tree,
 
 	for (i = 0; i < active_nr; i++) {
 		struct cache_entry *ce = active_cache[i];
+		struct string_list_item *item;
+
 		if (ce->ce_flags & CE_UPDATE)
 			continue;
 		if (!match_pathspec(pattern, ce->name, ce_namelen(ce), 0, m))
 			continue;
-		string_list_insert(ce->name, list);
+		item = string_list_insert(list, ce->name);
+		if (ce_skip_worktree(ce))
+			item->util = item; /* better a valid pointer than a fake one */
 	}
 
 	return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
@@ -181,6 +235,10 @@ static void add_remove_files(struct string_list *list)
 		struct stat st;
 		struct string_list_item *p = &(list->items[i]);
 
+		/* p->util is skip-worktree */
+		if (p->util)
+			continue;
+
 		if (!lstat(p->string, &st)) {
 			if (add_to_cache(p->string, &st, 0))
 				die("updating files failed");
@@ -217,12 +275,25 @@ static void create_base_index(void)
 		exit(128); /* We've already reported the error, finish dying */
 }
 
-static char *prepare_index(int argc, const char **argv, const char *prefix)
+static void refresh_cache_or_die(int refresh_flags)
+{
+	/*
+	 * refresh_flags contains REFRESH_QUIET, so the only errors
+	 * are for unmerged entries.
+	 */
+	if (refresh_cache(refresh_flags | REFRESH_IN_PORCELAIN))
+		die_resolve_conflict("commit");
+}
+
+static char *prepare_index(int argc, const char **argv, const char *prefix, int is_status)
 {
 	int fd;
 	struct string_list partial;
 	const char **pathspec = NULL;
+	int refresh_flags = REFRESH_QUIET;
 
+	if (is_status)
+		refresh_flags |= REFRESH_UNMERGED;
 	if (interactive) {
 		if (interactive_add(argc, argv, prefix) != 0)
 			die("interactive add failed");
@@ -251,9 +322,9 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 	 * (B) on failure, rollback the real index.
 	 */
 	if (all || (also && pathspec && *pathspec)) {
-		int fd = hold_locked_index(&index_lock, 1);
+		fd = hold_locked_index(&index_lock, 1);
 		add_files_to_cache(also ? prefix : NULL, pathspec, 0);
-		refresh_cache(REFRESH_QUIET);
+		refresh_cache_or_die(refresh_flags);
 		if (write_cache(fd, active_cache, active_nr) ||
 		    close_lock_file(&index_lock))
 			die("unable to write new_index file");
@@ -266,16 +337,20 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 	 *
 	 * (1) return the name of the real index file.
 	 *
-	 * The caller should run hooks on the real index, and run
-	 * hooks on the real index, and create commit from the_index.
+	 * The caller should run hooks on the real index,
+	 * and create commit from the_index.
 	 * We still need to refresh the index here.
 	 */
 	if (!pathspec || !*pathspec) {
 		fd = hold_locked_index(&index_lock, 1);
-		refresh_cache(REFRESH_QUIET);
-		if (write_cache(fd, active_cache, active_nr) ||
-		    commit_locked_index(&index_lock))
-			die("unable to write new_index file");
+		refresh_cache_or_die(refresh_flags);
+		if (active_cache_changed) {
+			if (write_cache(fd, active_cache, active_nr) ||
+			    commit_locked_index(&index_lock))
+				die("unable to write new_index file");
+		} else {
+			rollback_lock_file(&index_lock);
+		}
 		commit_style = COMMIT_AS_IS;
 		return get_index_file();
 	}
@@ -301,7 +376,7 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 	 */
 	commit_style = COMMIT_PARTIAL;
 
-	if (file_exists(git_path("MERGE_HEAD")))
+	if (in_merge)
 		die("cannot do a partial commit during a merge.");
 
 	memset(&partial, 0, sizeof(partial));
@@ -339,27 +414,39 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 	return false_lock.filename;
 }
 
-static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn)
+static int run_status(FILE *fp, const char *index_file, const char *prefix, int nowarn,
+		      struct wt_status *s)
 {
-	struct wt_status s;
+	unsigned char sha1[20];
 
-	wt_status_prepare(&s);
-	if (wt_status_relative_paths)
-		s.prefix = prefix;
+	if (s->relative_paths)
+		s->prefix = prefix;
 
 	if (amend) {
-		s.amend = 1;
-		s.reference = "HEAD^1";
+		s->amend = 1;
+		s->reference = "HEAD^1";
 	}
-	s.verbose = verbose;
-	s.untracked = (show_untracked_files == SHOW_ALL_UNTRACKED_FILES);
-	s.index_file = index_file;
-	s.fp = fp;
-	s.nowarn = nowarn;
+	s->verbose = verbose;
+	s->index_file = index_file;
+	s->fp = fp;
+	s->nowarn = nowarn;
+	s->is_initial = get_sha1(s->reference, sha1) ? 1 : 0;
 
-	wt_status_print(&s);
+	wt_status_collect(s);
 
-	return s.commitable;
+	switch (status_format) {
+	case STATUS_FORMAT_SHORT:
+		wt_shortstatus_print(s, null_termination, status_show_branch);
+		break;
+	case STATUS_FORMAT_PORCELAIN:
+		wt_porcelain_print(s, null_termination);
+		break;
+	case STATUS_FORMAT_LONG:
+		wt_status_print(s);
+		break;
+	}
+
+	return s->commitable;
 }
 
 static int is_a_merge(const unsigned char *sha1)
@@ -380,22 +467,28 @@ static void determine_author_info(void)
 	email = getenv("GIT_AUTHOR_EMAIL");
 	date = getenv("GIT_AUTHOR_DATE");
 
-	if (use_message) {
+	if (use_message && !renew_authorship) {
 		const char *a, *lb, *rb, *eol;
 
 		a = strstr(use_message_buffer, "\nauthor ");
 		if (!a)
 			die("invalid commit: %s", use_message);
 
-		lb = strstr(a + 8, " <");
-		rb = strstr(a + 8, "> ");
-		eol = strchr(a + 8, '\n');
-		if (!lb || !rb || !eol)
+		lb = strchrnul(a + strlen("\nauthor "), '<');
+		rb = strchrnul(lb, '>');
+		eol = strchrnul(rb, '\n');
+		if (!*lb || !*rb || !*eol)
 			die("invalid commit: %s", use_message);
 
-		name = xstrndup(a + 8, lb - (a + 8));
-		email = xstrndup(lb + 2, rb - (lb + 2));
-		date = xstrndup(rb + 2, eol - (rb + 2));
+		if (lb == a + strlen("\nauthor "))
+			/* \nauthor <foo@example.com> */
+			name = xcalloc(1, 1);
+		else
+			name = xmemdupz(a + strlen("\nauthor "),
+					(lb - strlen(" ") -
+					 (a + strlen("\nauthor "))));
+		email = xmemdupz(lb + strlen("<"), rb - (lb + strlen("<")));
+		date = xmemdupz(rb + strlen("> "), eol - (rb + strlen("> ")));
 	}
 
 	if (force_author) {
@@ -408,12 +501,57 @@ static void determine_author_info(void)
 		email = xstrndup(lb + 2, rb - (lb + 2));
 	}
 
+	if (force_date)
+		date = force_date;
+
 	author_name = name;
 	author_email = email;
 	author_date = date;
 }
 
-static int prepare_to_commit(const char *index_file, const char *prefix)
+static int ends_rfc2822_footer(struct strbuf *sb)
+{
+	int ch;
+	int hit = 0;
+	int i, j, k;
+	int len = sb->len;
+	int first = 1;
+	const char *buf = sb->buf;
+
+	for (i = len - 1; i > 0; i--) {
+		if (hit && buf[i] == '\n')
+			break;
+		hit = (buf[i] == '\n');
+	}
+
+	while (i < len - 1 && buf[i] == '\n')
+		i++;
+
+	for (; i < len; i = k) {
+		for (k = i; k < len && buf[k] != '\n'; k++)
+			; /* do nothing */
+		k++;
+
+		if ((buf[k] == ' ' || buf[k] == '\t') && !first)
+			continue;
+
+		first = 0;
+
+		for (j = 0; i + j < len; j++) {
+			ch = buf[i + j];
+			if (ch == ':')
+				break;
+			if (isalnum(ch) ||
+			    (ch == '-'))
+				continue;
+			return 0;
+		}
+	}
+	return 1;
+}
+
+static int prepare_to_commit(const char *index_file, const char *prefix,
+			     struct wt_status *s)
 {
 	struct stat statbuf;
 	int commitable, saved_color_setting;
@@ -434,12 +572,12 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 		if (isatty(0))
 			fprintf(stderr, "(reading log message from standard input)\n");
 		if (strbuf_read(&sb, 0, 0) < 0)
-			die("could not read log from standard input");
+			die_errno("could not read log from standard input");
 		hook_arg1 = "message";
 	} else if (logfile) {
 		if (strbuf_read_file(&sb, logfile, 0) < 0)
-			die("could not read log file '%s': %s",
-			    logfile, strerror(errno));
+			die_errno("could not read log file '%s'",
+				  logfile);
 		hook_arg1 = "message";
 	} else if (use_message) {
 		buffer = strstr(use_message_buffer, "\n\n");
@@ -450,16 +588,15 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 		hook_arg2 = use_message;
 	} else if (!stat(git_path("MERGE_MSG"), &statbuf)) {
 		if (strbuf_read_file(&sb, git_path("MERGE_MSG"), 0) < 0)
-			die("could not read MERGE_MSG: %s", strerror(errno));
+			die_errno("could not read MERGE_MSG");
 		hook_arg1 = "merge";
 	} else if (!stat(git_path("SQUASH_MSG"), &statbuf)) {
 		if (strbuf_read_file(&sb, git_path("SQUASH_MSG"), 0) < 0)
-			die("could not read SQUASH_MSG: %s", strerror(errno));
+			die_errno("could not read SQUASH_MSG");
 		hook_arg1 = "squash";
 	} else if (template_file && !stat(template_file, &statbuf)) {
 		if (strbuf_read_file(&sb, template_file, 0) < 0)
-			die("could not read %s: %s",
-			    template_file, strerror(errno));
+			die_errno("could not read '%s'", template_file);
 		hook_arg1 = "template";
 	}
 
@@ -472,8 +609,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 
 	fp = fopen(git_path(commit_editmsg), "w");
 	if (fp == NULL)
-		die("could not open %s: %s",
-		    git_path(commit_editmsg), strerror(errno));
+		die_errno("could not open '%s'", git_path(commit_editmsg));
 
 	if (cleanup_mode != CLEANUP_NONE)
 		stripspace(&sb, 0);
@@ -489,7 +625,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 		for (i = sb.len - 1; i > 0 && sb.buf[i - 1] != '\n'; i--)
 			; /* do nothing */
 		if (prefixcmp(sb.buf + i, sob.buf)) {
-			if (prefixcmp(sb.buf + i, sign_off_header))
+			if (!i || !ends_rfc2822_footer(&sb))
 				strbuf_addch(&sb, '\n');
 			strbuf_addbuf(&sb, &sob);
 		}
@@ -497,7 +633,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 	}
 
 	if (fwrite(sb.buf, 1, sb.len, fp) < sb.len)
-		die("could not write commit template: %s", strerror(errno));
+		die_errno("could not write commit template");
 
 	strbuf_release(&sb);
 
@@ -505,7 +641,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 
 	/* This checks if committer ident is explicitly given */
 	git_committer_info(0);
-	if (use_editor) {
+	if (use_editor && include_status) {
 		char *author_ident;
 		const char *committer_ident;
 
@@ -547,7 +683,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 				author_ident);
 		free(author_ident);
 
-		if (!user_ident_explicitly_given)
+		if (!user_ident_sufficiently_given())
 			fprintf(fp,
 				"%s"
 				"# Committer: %s\n",
@@ -557,10 +693,10 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 		if (ident_shown)
 			fprintf(fp, "#\n");
 
-		saved_color_setting = wt_status_use_color;
-		wt_status_use_color = 0;
-		commitable = run_status(fp, index_file, prefix, 1);
-		wt_status_use_color = saved_color_setting;
+		saved_color_setting = s->use_color;
+		s->use_color = 0;
+		commitable = run_status(fp, index_file, prefix, 1, s);
+		s->use_color = saved_color_setting;
 	} else {
 		unsigned char sha1[20];
 		const char *parent = "HEAD";
@@ -581,7 +717,9 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 
 	if (!commitable && !in_merge && !allow_empty &&
 	    !(amend && is_a_merge(head_sha1))) {
-		run_status(stdout, index_file, prefix, 0);
+		run_status(stdout, index_file, prefix, 0, s);
+		if (amend)
+			fputs(empty_amend_advice, stderr);
 		return 0;
 	}
 
@@ -606,7 +744,8 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 
 	if (use_editor) {
 		char index[PATH_MAX];
-		const char *env[2] = { index, NULL };
+		const char *env[2] = { NULL };
+		env[0] =  index;
 		snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
 		if (launch_editor(git_path(commit_editmsg), NULL, env)) {
 			fprintf(stderr,
@@ -684,26 +823,46 @@ static const char *find_author_by_nickname(const char *name)
 	prepare_revision_walk(&revs);
 	commit = get_revision(&revs);
 	if (commit) {
+		struct pretty_print_context ctx = {0};
+		ctx.date_mode = DATE_NORMAL;
 		strbuf_release(&buf);
-		format_commit_message(commit, "%an <%ae>", &buf, DATE_NORMAL);
+		format_commit_message(commit, "%an <%ae>", &buf, &ctx);
 		return strbuf_detach(&buf, NULL);
 	}
 	die("No existing author found with '%s'", name);
 }
 
+
+static void handle_untracked_files_arg(struct wt_status *s)
+{
+	if (!untracked_files_arg)
+		; /* default already initialized */
+	else if (!strcmp(untracked_files_arg, "no"))
+		s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
+	else if (!strcmp(untracked_files_arg, "normal"))
+		s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
+	else if (!strcmp(untracked_files_arg, "all"))
+		s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
+	else
+		die("Invalid untracked files mode '%s'", untracked_files_arg);
+}
+
 static int parse_and_validate_options(int argc, const char *argv[],
 				      const char * const usage[],
-				      const char *prefix)
+				      const char *prefix,
+				      struct wt_status *s)
 {
 	int f = 0;
 
-	argc = parse_options(argc, argv, builtin_commit_options, usage, 0);
-	logfile = parse_options_fix_filename(prefix, logfile);
-	template_file = parse_options_fix_filename(prefix, template_file);
+	argc = parse_options(argc, argv, prefix, builtin_commit_options, usage,
+			     0);
 
 	if (force_author && !strchr(force_author, '>'))
 		force_author = find_author_by_nickname(force_author);
 
+	if (force_author && renew_authorship)
+		die("Using both --reset-author and --author does not make sense");
+
 	if (logfile || message.len || use_message)
 		use_editor = 0;
 	if (edit_flag)
@@ -714,9 +873,6 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	if (get_sha1("HEAD", head_sha1))
 		initial_commit = 1;
 
-	if (!get_sha1("MERGE_HEAD", merge_head_sha1))
-		in_merge = 1;
-
 	/* Sanity check options */
 	if (amend && initial_commit)
 		die("You have nothing to amend.");
@@ -737,6 +893,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
 		use_message = edit_message;
 	if (amend && !use_message)
 		use_message = "HEAD";
+	if (!use_message && renew_authorship)
+		die("--reset-author can be used only with -C, -c or --amend.");
 	if (use_message) {
 		unsigned char sha1[20];
 		static char utf8[] = "UTF-8";
@@ -794,56 +952,190 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	else
 		die("Invalid cleanup mode %s", cleanup_arg);
 
-	if (!untracked_files_arg)
-		; /* default already initialized */
-	else if (!strcmp(untracked_files_arg, "no"))
-		show_untracked_files = SHOW_NO_UNTRACKED_FILES;
-	else if (!strcmp(untracked_files_arg, "normal"))
-		show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
-	else if (!strcmp(untracked_files_arg, "all"))
-		show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
-	else
-		die("Invalid untracked files mode '%s'", untracked_files_arg);
+	handle_untracked_files_arg(s);
 
 	if (all && argc > 0)
 		die("Paths with -a does not make sense.");
 	else if (interactive && argc > 0)
 		die("Paths with --interactive does not make sense.");
 
+	if (null_termination && status_format == STATUS_FORMAT_LONG)
+		status_format = STATUS_FORMAT_PORCELAIN;
+	if (status_format != STATUS_FORMAT_LONG)
+		dry_run = 1;
+
 	return argc;
 }
 
-int cmd_status(int argc, const char **argv, const char *prefix)
+static int dry_run_commit(int argc, const char **argv, const char *prefix,
+			  struct wt_status *s)
 {
-	const char *index_file;
 	int commitable;
+	const char *index_file;
 
-	git_config(git_status_config, NULL);
+	index_file = prepare_index(argc, argv, prefix, 1);
+	commitable = run_status(stdout, index_file, prefix, 0, s);
+	rollback_index_files();
 
-	if (wt_status_use_color == -1)
-		wt_status_use_color = git_use_color_default;
+	return commitable ? 0 : 1;
+}
 
-	if (diff_use_color_default == -1)
-		diff_use_color_default = git_use_color_default;
+static int parse_status_slot(const char *var, int offset)
+{
+	if (!strcasecmp(var+offset, "header"))
+		return WT_STATUS_HEADER;
+	if (!strcasecmp(var+offset, "updated")
+		|| !strcasecmp(var+offset, "added"))
+		return WT_STATUS_UPDATED;
+	if (!strcasecmp(var+offset, "changed"))
+		return WT_STATUS_CHANGED;
+	if (!strcasecmp(var+offset, "untracked"))
+		return WT_STATUS_UNTRACKED;
+	if (!strcasecmp(var+offset, "nobranch"))
+		return WT_STATUS_NOBRANCH;
+	if (!strcasecmp(var+offset, "unmerged"))
+		return WT_STATUS_UNMERGED;
+	return -1;
+}
 
-	argc = parse_and_validate_options(argc, argv, builtin_status_usage, prefix);
+static int git_status_config(const char *k, const char *v, void *cb)
+{
+	struct wt_status *s = cb;
 
-	index_file = prepare_index(argc, argv, prefix);
+	if (!strcmp(k, "status.submodulesummary")) {
+		int is_bool;
+		s->submodule_summary = git_config_bool_or_int(k, v, &is_bool);
+		if (is_bool && s->submodule_summary)
+			s->submodule_summary = -1;
+		return 0;
+	}
+	if (!strcmp(k, "status.color") || !strcmp(k, "color.status")) {
+		s->use_color = git_config_colorbool(k, v, -1);
+		return 0;
+	}
+	if (!prefixcmp(k, "status.color.") || !prefixcmp(k, "color.status.")) {
+		int slot = parse_status_slot(k, 13);
+		if (slot < 0)
+			return 0;
+		if (!v)
+			return config_error_nonbool(k);
+		color_parse(v, k, s->color_palette[slot]);
+		return 0;
+	}
+	if (!strcmp(k, "status.relativepaths")) {
+		s->relative_paths = git_config_bool(k, v);
+		return 0;
+	}
+	if (!strcmp(k, "status.showuntrackedfiles")) {
+		if (!v)
+			return config_error_nonbool(k);
+		else if (!strcmp(v, "no"))
+			s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
+		else if (!strcmp(v, "normal"))
+			s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
+		else if (!strcmp(v, "all"))
+			s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
+		else
+			return error("Invalid untracked files mode '%s'", v);
+		return 0;
+	}
+	return git_diff_ui_config(k, v, NULL);
+}
 
-	commitable = run_status(stdout, index_file, prefix, 0);
+int cmd_status(int argc, const char **argv, const char *prefix)
+{
+	struct wt_status s;
+	int fd;
+	unsigned char sha1[20];
+	static struct option builtin_status_options[] = {
+		OPT__VERBOSE(&verbose),
+		OPT_SET_INT('s', "short", &status_format,
+			    "show status concisely", STATUS_FORMAT_SHORT),
+		OPT_BOOLEAN('b', "branch", &status_show_branch,
+			    "show branch information"),
+		OPT_SET_INT(0, "porcelain", &status_format,
+			    "show porcelain output format",
+			    STATUS_FORMAT_PORCELAIN),
+		OPT_BOOLEAN('z', "null", &null_termination,
+			    "terminate entries with NUL"),
+		{ OPTION_STRING, 'u', "untracked-files", &untracked_files_arg,
+		  "mode",
+		  "show untracked files, optional modes: all, normal, no. (Default: all)",
+		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+		OPT_BOOLEAN(0, "ignored", &show_ignored_in_status,
+			    "show ignored files"),
+		{ OPTION_STRING, 0, "ignore-submodules", &ignore_submodule_arg, "when",
+		  "ignore changes to submodules, optional when: all, dirty, untracked. (Default: all)",
+		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
+		OPT_END(),
+	};
+
+	if (null_termination && status_format == STATUS_FORMAT_LONG)
+		status_format = STATUS_FORMAT_PORCELAIN;
 
-	rollback_index_files();
+	wt_status_prepare(&s);
+	gitmodules_config();
+	git_config(git_status_config, &s);
+	in_merge = file_exists(git_path("MERGE_HEAD"));
+	argc = parse_options(argc, argv, prefix,
+			     builtin_status_options,
+			     builtin_status_usage, 0);
+	handle_untracked_files_arg(&s);
+	if (show_ignored_in_status)
+		s.show_ignored_files = 1;
+	if (*argv)
+		s.pathspec = get_pathspec(prefix, argv);
 
-	return commitable ? 0 : 1;
+	read_cache_preload(s.pathspec);
+	refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, s.pathspec, NULL, NULL);
+
+	fd = hold_locked_index(&index_lock, 0);
+	if (0 <= fd) {
+		if (active_cache_changed &&
+		    !write_cache(fd, active_cache, active_nr))
+			commit_locked_index(&index_lock);
+		else
+			rollback_lock_file(&index_lock);
+	}
+
+	s.is_initial = get_sha1(s.reference, sha1) ? 1 : 0;
+	s.in_merge = in_merge;
+	s.ignore_submodule_arg = ignore_submodule_arg;
+	wt_status_collect(&s);
+
+	if (s.relative_paths)
+		s.prefix = prefix;
+	if (s.use_color == -1)
+		s.use_color = git_use_color_default;
+	if (diff_use_color_default == -1)
+		diff_use_color_default = git_use_color_default;
+
+	switch (status_format) {
+	case STATUS_FORMAT_SHORT:
+		wt_shortstatus_print(&s, null_termination, status_show_branch);
+		break;
+	case STATUS_FORMAT_PORCELAIN:
+		wt_porcelain_print(&s, null_termination);
+		break;
+	case STATUS_FORMAT_LONG:
+		s.verbose = verbose;
+		s.ignore_submodule_arg = ignore_submodule_arg;
+		wt_status_print(&s);
+		break;
+	}
+	return 0;
 }
 
 static void print_summary(const char *prefix, const unsigned char *sha1)
 {
 	struct rev_info rev;
 	struct commit *commit;
-	static const char *format = "format:%h] %s";
+	struct strbuf format = STRBUF_INIT;
 	unsigned char junk_sha1[20];
 	const char *head = resolve_ref("HEAD", junk_sha1, 0, NULL);
+	struct pretty_print_context pctx = {0};
+	struct strbuf author_ident = STRBUF_INIT;
+	struct strbuf committer_ident = STRBUF_INIT;
 
 	commit = lookup_commit(sha1);
 	if (!commit)
@@ -851,17 +1143,35 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 	if (!commit || parse_commit(commit))
 		die("could not parse newly created commit");
 
+	strbuf_addstr(&format, "format:%h] %s");
+
+	format_commit_message(commit, "%an <%ae>", &author_ident, &pctx);
+	format_commit_message(commit, "%cn <%ce>", &committer_ident, &pctx);
+	if (strbuf_cmp(&author_ident, &committer_ident)) {
+		strbuf_addstr(&format, "\n Author: ");
+		strbuf_addbuf_percentquote(&format, &author_ident);
+	}
+	if (!user_ident_sufficiently_given()) {
+		strbuf_addstr(&format, "\n Committer: ");
+		strbuf_addbuf_percentquote(&format, &committer_ident);
+		if (advice_implicit_identity) {
+			strbuf_addch(&format, '\n');
+			strbuf_addstr(&format, implicit_ident_advice);
+		}
+	}
+	strbuf_release(&author_ident);
+	strbuf_release(&committer_ident);
+
 	init_revisions(&rev, prefix);
 	setup_revisions(0, NULL, &rev, NULL);
 
-	rev.abbrev = 0;
 	rev.diff = 1;
 	rev.diffopt.output_format =
 		DIFF_FORMAT_SHORTSTAT | DIFF_FORMAT_SUMMARY;
 
 	rev.verbose_header = 1;
 	rev.show_root_diff = 1;
-	get_commit_format(format, &rev);
+	get_commit_format(format.buf, &rev);
 	rev.always_show_header = 0;
 	rev.diffopt.detect_rename = 1;
 	rev.diffopt.rename_limit = 100;
@@ -877,19 +1187,60 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 		initial_commit ? " (root-commit)" : "");
 
 	if (!log_tree_commit(&rev, commit)) {
-		struct strbuf buf = STRBUF_INIT;
-		format_commit_message(commit, format + 7, &buf, DATE_NORMAL);
-		printf("%s\n", buf.buf);
-		strbuf_release(&buf);
+		rev.always_show_header = 1;
+		rev.use_terminator = 1;
+		log_tree_commit(&rev, commit);
 	}
+
+	strbuf_release(&format);
 }
 
 static int git_commit_config(const char *k, const char *v, void *cb)
 {
+	struct wt_status *s = cb;
+
 	if (!strcmp(k, "commit.template"))
-		return git_config_string(&template_file, k, v);
+		return git_config_pathname(&template_file, k, v);
+	if (!strcmp(k, "commit.status")) {
+		include_status = git_config_bool(k, v);
+		return 0;
+	}
+
+	return git_status_config(k, v, s);
+}
+
+static const char post_rewrite_hook[] = "hooks/post-rewrite";
+
+static int run_rewrite_hook(const unsigned char *oldsha1,
+			    const unsigned char *newsha1)
+{
+	/* oldsha1 SP newsha1 LF NUL */
+	static char buf[2*40 + 3];
+	struct child_process proc;
+	const char *argv[3];
+	int code;
+	size_t n;
+
+	if (access(git_path(post_rewrite_hook), X_OK) < 0)
+		return 0;
 
-	return git_status_config(k, v, cb);
+	argv[0] = git_path(post_rewrite_hook);
+	argv[1] = "amend";
+	argv[2] = NULL;
+
+	memset(&proc, 0, sizeof(proc));
+	proc.argv = argv;
+	proc.in = -1;
+	proc.stdout_to_stderr = 1;
+
+	code = start_command(&proc);
+	if (code)
+		return code;
+	n = snprintf(buf, sizeof(buf), "%s %s\n",
+		     sha1_to_hex(oldsha1), sha1_to_hex(newsha1));
+	write_in_full(proc.in, buf, n);
+	close(proc.in);
+	return finish_command(&proc);
 }
 
 int cmd_commit(int argc, const char **argv, const char *prefix)
@@ -902,31 +1253,42 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	struct commit_list *parents = NULL, **pptr = &parents;
 	struct stat statbuf;
 	int allow_fast_forward = 1;
+	struct wt_status s;
 
-	git_config(git_commit_config, NULL);
-
-	if (wt_status_use_color == -1)
-		wt_status_use_color = git_use_color_default;
-
-	argc = parse_and_validate_options(argc, argv, builtin_commit_usage, prefix);
-
-	index_file = prepare_index(argc, argv, prefix);
+	wt_status_prepare(&s);
+	git_config(git_commit_config, &s);
+	in_merge = file_exists(git_path("MERGE_HEAD"));
+	s.in_merge = in_merge;
+
+	if (s.use_color == -1)
+		s.use_color = git_use_color_default;
+	argc = parse_and_validate_options(argc, argv, builtin_commit_usage,
+					  prefix, &s);
+	if (dry_run) {
+		if (diff_use_color_default == -1)
+			diff_use_color_default = git_use_color_default;
+		return dry_run_commit(argc, argv, prefix, &s);
+	}
+	index_file = prepare_index(argc, argv, prefix, 0);
 
 	/* Set up everything for writing the commit object.  This includes
 	   running hooks, writing the trees, and interacting with the user.  */
-	if (!prepare_to_commit(index_file, prefix)) {
+	if (!prepare_to_commit(index_file, prefix, &s)) {
 		rollback_index_files();
 		return 1;
 	}
 
 	/* Determine parents */
+	reflog_msg = getenv("GIT_REFLOG_ACTION");
 	if (initial_commit) {
-		reflog_msg = "commit (initial)";
+		if (!reflog_msg)
+			reflog_msg = "commit (initial)";
 	} else if (amend) {
 		struct commit_list *c;
 		struct commit *commit;
 
-		reflog_msg = "commit (amend)";
+		if (!reflog_msg)
+			reflog_msg = "commit (amend)";
 		commit = lookup_commit(head_sha1);
 		if (!commit || parse_commit(commit))
 			die("could not parse HEAD commit");
@@ -937,12 +1299,13 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		struct strbuf m = STRBUF_INIT;
 		FILE *fp;
 
-		reflog_msg = "commit (merge)";
+		if (!reflog_msg)
+			reflog_msg = "commit (merge)";
 		pptr = &commit_list_insert(lookup_commit(head_sha1), pptr)->next;
 		fp = fopen(git_path("MERGE_HEAD"), "r");
 		if (fp == NULL)
-			die("could not open %s for reading: %s",
-			    git_path("MERGE_HEAD"), strerror(errno));
+			die_errno("could not open '%s' for reading",
+				  git_path("MERGE_HEAD"));
 		while (strbuf_getline(&m, fp, '\n') != EOF) {
 			unsigned char sha1[20];
 			if (get_sha1_hex(m.buf, sha1) < 0)
@@ -953,23 +1316,24 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		strbuf_release(&m);
 		if (!stat(git_path("MERGE_MODE"), &statbuf)) {
 			if (strbuf_read_file(&sb, git_path("MERGE_MODE"), 0) < 0)
-				die("could not read MERGE_MODE: %s",
-						strerror(errno));
+				die_errno("could not read MERGE_MODE");
 			if (!strcmp(sb.buf, "no-ff"))
 				allow_fast_forward = 0;
 		}
 		if (allow_fast_forward)
 			parents = reduce_heads(parents);
 	} else {
-		reflog_msg = "commit";
+		if (!reflog_msg)
+			reflog_msg = "commit";
 		pptr = &commit_list_insert(lookup_commit(head_sha1), pptr)->next;
 	}
 
 	/* Finally, get the commit message */
 	strbuf_reset(&sb);
 	if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
+		int saved_errno = errno;
 		rollback_index_files();
-		die("could not read commit message");
+		die("could not read commit message: %s", strerror(saved_errno));
 	}
 
 	/* Truncate the message just before the diff, if any. */
@@ -981,7 +1345,7 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 
 	if (cleanup_mode != CLEANUP_NONE)
 		stripspace(&sb, cleanup_mode == CLEANUP_ALL);
-	if (message_is_empty(&sb)) {
+	if (message_is_empty(&sb) && !allow_empty_message) {
 		rollback_index_files();
 		fprintf(stderr, "Aborting commit due to empty commit message.\n");
 		exit(1);
@@ -1025,8 +1389,17 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		     "new_index file. Check that disk is not full or quota is\n"
 		     "not exceeded, and then \"git reset HEAD\" to recover.");
 
-	rerere();
+	rerere(0);
 	run_hook(get_index_file(), "post-commit", NULL);
+	if (amend && !no_post_rewrite) {
+		struct notes_rewrite_cfg *cfg;
+		cfg = init_copy_notes_for_rewrite("amend");
+		if (cfg) {
+			copy_note_for_rewrite(cfg, head_sha1, commit_sha1);
+			finish_copy_notes_for_rewrite(cfg);
+		}
+		run_rewrite_hook(head_sha1, commit_sha1);
+	}
 	if (!quiet)
 		print_summary(prefix, commit_sha1);