tag.c: Parse tagger date (if present)
[gitweb.git] / builtin-commit.c
index bf01ae776be92fcdf4878a008464777185a08e4b..83b7c353ed6e4ca99a9bfae041c41280d31122a7 100644 (file)
@@ -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");
@@ -273,11 +278,13 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
         * 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");
+               fd = hold_locked_index(&index_lock, !is_status);
+               refresh_cache(refresh_flags);
+               if (0 <= fd) {
+                       if (write_cache(fd, active_cache, active_nr) ||
+                           commit_locked_index(&index_lock))
+                               die("unable to write new_index file");
+               }
                commit_style = COMMIT_AS_IS;
                return get_index_file();
        }
@@ -341,61 +348,24 @@ 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 +386,7 @@ 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 +419,49 @@ 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 +482,12 @@ 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 +498,15 @@ 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 +519,7 @@ 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 +535,7 @@ 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 +543,7 @@ 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 +603,11 @@ 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 +619,15 @@ 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 +730,10 @@ 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 +741,20 @@ 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 +788,8 @@ 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 +850,11 @@ 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 +866,102 @@ 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 +988,7 @@ 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 +997,10 @@ 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 +1008,12 @@ 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 +1026,26 @@ 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 +1072,8 @@ 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 +1084,7 @@ 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 +1098,9 @@ 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. */