1 files changed, 207 insertions, 123 deletions

diff --git a/builtin-commit.c b/builtin-commit.c
index bf01ae776..33aa593c2 100644
--- a/builtin-commit.c
+++ b/builtin-commit.c
@@ -51,7 +51,7 @@ 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 int quiet, verbose, no_verify, allow_empty, dry_run, renew_authorship;
 static char *untracked_files_arg;
 /*
  * The default commit message cleanup mode will remove the lines
@@ -88,13 +88,14 @@ static struct option builtin_commit_options[] = {
 	OPT__VERBOSE(&verbose),
 
 	OPT_GROUP("Commit message options"),
-	OPT_STRING('F', "file", &logfile, "FILE", "read log from file"),
+	OPT_FILENAME('F', "file", &logfile, "read log from file"),
 	OPT_STRING(0, "author", &force_author, "AUTHOR", "override author 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"),
 	/* end commit message options */
@@ -105,6 +106,7 @@ 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_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"),
@@ -168,7 +170,7 @@ static int list_paths(struct string_list *list, const char *with_tree,
 		struct cache_entry *ce = active_cache[i];
 		if (ce->ce_flags & CE_UPDATE)
 			continue;
-		if (!pathspec_match(pattern, m, ce->name, 0))
+		if (!match_pathspec(pattern, ce->name, ce_namelen(ce), 0, m))
 			continue;
 		string_list_insert(ce->name, list);
 	}
@@ -219,12 +221,15 @@ 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 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");
@@ -255,7 +260,7 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 	if (all || (also && pathspec && *pathspec)) {
 		int fd = hold_locked_index(&index_lock, 1);
 		add_files_to_cache(also ? prefix : NULL, pathspec, 0);
-		refresh_cache(REFRESH_QUIET);
+		refresh_cache(refresh_flags);
 		if (write_cache(fd, active_cache, active_nr) ||
 		    close_lock_file(&index_lock))
 			die("unable to write new_index file");
@@ -274,7 +279,7 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
 	 */
 	if (!pathspec || !*pathspec) {
 		fd = hold_locked_index(&index_lock, 1);
-		refresh_cache(REFRESH_QUIET);
+		refresh_cache(refresh_flags);
 		if (write_cache(fd, active_cache, active_nr) ||
 		    commit_locked_index(&index_lock))
 			die("unable to write new_index file");
@@ -341,61 +346,24 @@ 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;
-
-	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;
 
-	wt_status_print(&s);
+	wt_status_print(s);
 
-	return s.commitable;
-}
-
-static int run_hook(const char *index_file, const char *name, ...)
-{
-	struct child_process hook;
-	const char *argv[10], *env[2];
-	char index[PATH_MAX];
-	va_list args;
-	int i;
-
-	va_start(args, name);
-	argv[0] = git_path("hooks/%s", name);
-	i = 0;
-	do {
-		if (++i >= ARRAY_SIZE(argv))
-			die ("run_hook(): too many arguments");
-		argv[i] = va_arg(args, const char *);
-	} while (argv[i]);
-	va_end(args);
-
-	snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
-	env[0] = index;
-	env[1] = NULL;
-
-	if (access(argv[0], X_OK) < 0)
-		return 0;
-
-	memset(&hook, 0, sizeof(hook));
-	hook.argv = argv;
-	hook.no_stdin = 1;
-	hook.stdout_to_stderr = 1;
-	hook.env = env;
-
-	return run_command(&hook);
+	return s->commitable;
 }
 
 static int is_a_merge(const unsigned char *sha1)
@@ -416,7 +384,7 @@ 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 ");
@@ -449,7 +417,49 @@ static void determine_author_info(void)
 	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;
@@ -470,12 +480,12 @@ 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");
@@ -486,16 +496,15 @@ 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";
 	}
 
@@ -508,8 +517,7 @@ 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);
@@ -525,7 +533,7 @@ 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);
 		}
@@ -533,7 +541,7 @@ 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);
 
@@ -593,12 +601,11 @@ 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 {
-		struct rev_info rev;
 		unsigned char sha1[20];
 		const char *parent = "HEAD";
 
@@ -610,23 +617,15 @@ static int prepare_to_commit(const char *index_file, const char *prefix)
 
 		if (get_sha1(parent, sha1))
 			commitable = !!active_nr;
-		else {
-			init_revisions(&rev, "");
-			rev.abbrev = 0;
-			setup_revisions(0, NULL, &rev, parent);
-			DIFF_OPT_SET(&rev.diffopt, QUIET);
-			DIFF_OPT_SET(&rev.diffopt, EXIT_WITH_STATUS);
-			run_diff_index(&rev, 1 /* cached */);
-
-			commitable = !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
-		}
+		else
+			commitable = index_differs_from(parent, 0);
 	}
 
 	fclose(fp);
 
 	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);
 		return 0;
 	}
 
@@ -729,8 +728,10 @@ 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);
@@ -738,17 +739,20 @@ static const char *find_author_by_nickname(const char *name)
 
 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)
@@ -782,6 +786,8 @@ 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";
@@ -842,11 +848,11 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	if (!untracked_files_arg)
 		; /* default already initialized */
 	else if (!strcmp(untracked_files_arg, "no"))
-		show_untracked_files = SHOW_NO_UNTRACKED_FILES;
+		s->show_untracked_files = SHOW_NO_UNTRACKED_FILES;
 	else if (!strcmp(untracked_files_arg, "normal"))
-		show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
+		s->show_untracked_files = SHOW_NORMAL_UNTRACKED_FILES;
 	else if (!strcmp(untracked_files_arg, "all"))
-		show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
+		s->show_untracked_files = SHOW_ALL_UNTRACKED_FILES;
 	else
 		die("Invalid untracked files mode '%s'", untracked_files_arg);
 
@@ -858,35 +864,102 @@ static int parse_and_validate_options(int argc, const char *argv[],
 	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;
 
-	rollback_index_files();
+	wt_status_prepare(&s);
+	git_config(git_status_config, &s);
+	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;
 
-	return commitable ? 0 : 1;
+	argc = parse_and_validate_options(argc, argv, builtin_status_usage,
+					  prefix, &s);
+	return dry_run_commit(argc, argv, prefix, &s);
 }
 
 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\"";
+	static const char *format = "format:%h] %s";
 	unsigned char junk_sha1[20];
 	const char *head = resolve_ref("HEAD", junk_sha1, 0, NULL);
 
@@ -913,7 +986,7 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 	rev.diffopt.break_opt = 0;
 	diff_setup_done(&rev.diffopt);
 
-	printf("[%s%s]: created ",
+	printf("[%s%s ",
 		!prefixcmp(head, "refs/heads/") ?
 			head + 11 :
 			!strcmp(head, "HEAD") ?
@@ -922,8 +995,10 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 		initial_commit ? " (root-commit)" : "");
 
 	if (!log_tree_commit(&rev, commit)) {
+		struct pretty_print_context ctx = {0};
 		struct strbuf buf = STRBUF_INIT;
-		format_commit_message(commit, format + 7, &buf, DATE_NORMAL);
+		ctx.date_mode = DATE_NORMAL;
+		format_commit_message(commit, format + 7, &buf, &ctx);
 		printf("%s\n", buf.buf);
 		strbuf_release(&buf);
 	}
@@ -931,10 +1006,12 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 
 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);
 
-	return git_status_config(k, v, cb);
+	return git_status_config(k, v, s);
 }
 
 int cmd_commit(int argc, const char **argv, const char *prefix)
@@ -947,19 +1024,26 @@ 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;
+	wt_status_prepare(&s);
+	git_config(git_commit_config, &s);
 
-	argc = parse_and_validate_options(argc, argv, builtin_commit_usage, prefix);
+	if (s.use_color == -1)
+		s.use_color = git_use_color_default;
 
-	index_file = prepare_index(argc, argv, prefix);
+	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;
 	}
@@ -986,8 +1070,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 		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)
@@ -998,8 +1082,7 @@ 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;
 		}
@@ -1013,8 +1096,9 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
 	/* 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. */