git-daemon: Simplify dead-children reaping logic
[gitweb.git] / builtin-commit.c
index 2f4d6cc87e9c775f94bfd5463694f1408580f6a2..649c8beb3e716dd5797787ced61d2fee23b7140f 100644 (file)
@@ -7,6 +7,7 @@
 
 #include "cache.h"
 #include "cache-tree.h"
+#include "color.h"
 #include "dir.h"
 #include "builtin.h"
 #include "diff.h"
 #include "strbuf.h"
 #include "utf8.h"
 #include "parse-options.h"
-#include "path-list.h"
+#include "string-list.h"
+#include "rerere.h"
 #include "unpack-trees.h"
 
 static const char * const builtin_commit_usage[] = {
-       "git-commit [options] [--] <filepattern>...",
+       "git commit [options] [--] <filepattern>...",
        NULL
 };
 
 static const char * const builtin_status_usage[] = {
-       "git-status [options] [--] <filepattern>...",
+       "git status [options] [--] <filepattern>...",
        NULL
 };
 
@@ -44,10 +46,13 @@ static enum {
        COMMIT_PARTIAL,
 } commit_style;
 
-static char *logfile, *force_author, *template_file;
+static const char *logfile, *force_author;
+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, untracked_files, no_verify, allow_empty;
+static int quiet, verbose, no_verify, allow_empty;
+static char *untracked_files_arg;
 /*
  * The default commit message cleanup mode will remove the lines
  * beginning with # (shell comments) and leading and trailing
@@ -63,8 +68,8 @@ static enum {
 static char *cleanup_arg;
 
 static int use_editor = 1, initial_commit, in_merge;
-const char *only_include_assumed;
-struct strbuf message;
+static const char *only_include_assumed;
+static struct strbuf message;
 
 static int opt_parse_m(const struct option *opt, const char *arg, int unset)
 {
@@ -73,8 +78,7 @@ static int opt_parse_m(const struct option *opt, const char *arg, int unset)
                strbuf_setlen(buf, 0);
        else {
                strbuf_addstr(buf, arg);
-               strbuf_addch(buf, '\n');
-               strbuf_addch(buf, '\n');
+               strbuf_addstr(buf, "\n\n");
        }
        return 0;
 }
@@ -100,7 +104,7 @@ static struct option builtin_commit_options[] = {
        OPT_BOOLEAN('o', "only", &only, "commit only specified files"),
        OPT_BOOLEAN('n', "no-verify", &no_verify, "bypass pre-commit hook"),
        OPT_BOOLEAN(0, "amend", &amend, "amend previous commit"),
-       OPT_BOOLEAN('u', "untracked-files", &untracked_files, "show all untracked files"),
+       { 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"),
 
@@ -145,7 +149,7 @@ static int commit_index_files(void)
  * Take a union of paths in the index and the named tree (typically, "HEAD"),
  * and return the paths that match the given pattern in list.
  */
-static int list_paths(struct path_list *list, const char *with_tree,
+static int list_paths(struct string_list *list, const char *with_tree,
                      const char *prefix, const char **pattern)
 {
        int i;
@@ -160,25 +164,28 @@ static int list_paths(struct path_list *list, const char *with_tree,
 
        for (i = 0; i < active_nr; i++) {
                struct cache_entry *ce = active_cache[i];
-               if (ce->ce_flags & htons(CE_UPDATE))
+               if (ce->ce_flags & CE_UPDATE)
                        continue;
                if (!pathspec_match(pattern, m, ce->name, 0))
                        continue;
-               path_list_insert(ce->name, list);
+               string_list_insert(ce->name, list);
        }
 
        return report_path_error(m, pattern, prefix ? strlen(prefix) : 0);
 }
 
-static void add_remove_files(struct path_list *list)
+static void add_remove_files(struct string_list *list)
 {
        int i;
        for (i = 0; i < list->nr; i++) {
-               struct path_list_item *p = &(list->items[i]);
-               if (file_exists(p->path))
-                       add_file_to_cache(p->path, 0);
-               else
-                       remove_file_from_cache(p->path);
+               struct stat st;
+               struct string_list_item *p = &(list->items[i]);
+
+               if (!lstat(p->string, &st)) {
+                       if (add_to_cache(p->string, &st, 0))
+                               die("updating files failed");
+               } else
+                       remove_file_from_cache(p->string);
        }
 }
 
@@ -197,6 +204,8 @@ static void create_base_index(void)
        opts.head_idx = 1;
        opts.index_only = 1;
        opts.merge = 1;
+       opts.src_index = &the_index;
+       opts.dst_index = &the_index;
 
        opts.fn = oneway_merge;
        tree = parse_tree_indirect(head_sha1);
@@ -204,17 +213,20 @@ static void create_base_index(void)
                die("failed to unpack HEAD tree object");
        parse_tree(tree);
        init_tree_desc(&t, tree->buffer, tree->size);
-       unpack_trees(1, &t, &opts);
+       if (unpack_trees(1, &t, &opts))
+               exit(128); /* We've already reported the error, finish dying */
 }
 
 static char *prepare_index(int argc, const char **argv, const char *prefix)
 {
        int fd;
-       struct path_list partial;
+       struct string_list partial;
        const char **pathspec = NULL;
 
        if (interactive) {
                interactive_add(argc, argv, prefix);
+               if (read_cache() < 0)
+                       die("index file corrupt");
                commit_style = COMMIT_AS_IS;
                return get_index_file();
        }
@@ -239,7 +251,7 @@ 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(0, also ? prefix : NULL, pathspec);
+               add_files_to_cache(also ? prefix : NULL, pathspec, 0);
                refresh_cache(REFRESH_QUIET);
                if (write_cache(fd, active_cache, active_nr) ||
                    close_lock_file(&index_lock))
@@ -292,7 +304,7 @@ static char *prepare_index(int argc, const char **argv, const char *prefix)
                die("cannot do a partial commit during a merge.");
 
        memset(&partial, 0, sizeof(partial));
-       partial.strdup_paths = 1;
+       partial.strdup_strings = 1;
        if (list_paths(&partial, initial_commit ? NULL : "HEAD", prefix, pathspec))
                exit(1);
 
@@ -337,7 +349,7 @@ static int run_status(FILE *fp, const char *index_file, const char *prefix, int
                s.reference = "HEAD^1";
        }
        s.verbose = verbose;
-       s.untracked = untracked_files;
+       s.untracked = (show_untracked_files == SHOW_ALL_UNTRACKED_FILES);
        s.index_file = index_file;
        s.fp = fp;
        s.nowarn = nowarn;
@@ -347,48 +359,153 @@ static int run_status(FILE *fp, const char *index_file, const char *prefix, int
        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);
+}
+
+static int is_a_merge(const unsigned char *sha1)
+{
+       struct commit *commit = lookup_commit(sha1);
+       if (!commit || parse_commit(commit))
+               die("could not parse HEAD commit");
+       return !!(commit->parents && commit->parents->next);
+}
+
 static const char sign_off_header[] = "Signed-off-by: ";
 
-static int prepare_log_message(const char *index_file, const char *prefix)
+static void determine_author_info(void)
+{
+       char *name, *email, *date;
+
+       name = getenv("GIT_AUTHOR_NAME");
+       email = getenv("GIT_AUTHOR_EMAIL");
+       date = getenv("GIT_AUTHOR_DATE");
+
+       if (use_message) {
+               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)
+                       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 (force_author) {
+               const char *lb = strstr(force_author, " <");
+               const char *rb = strchr(force_author, '>');
+
+               if (!lb || !rb)
+                       die("malformed --author parameter");
+               name = xstrndup(force_author, lb - force_author);
+               email = xstrndup(lb + 2, rb - (lb + 2));
+       }
+
+       author_name = name;
+       author_email = email;
+       author_date = date;
+}
+
+static int prepare_to_commit(const char *index_file, const char *prefix)
 {
        struct stat statbuf;
        int commitable, saved_color_setting;
        struct strbuf sb;
        char *buffer;
        FILE *fp;
+       const char *hook_arg1 = NULL;
+       const char *hook_arg2 = NULL;
+       int ident_shown = 0;
+
+       if (!no_verify && run_hook(index_file, "pre-commit", NULL))
+               return 0;
 
        strbuf_init(&sb, 0);
        if (message.len) {
                strbuf_addbuf(&sb, &message);
+               hook_arg1 = "message";
        } else if (logfile && !strcmp(logfile, "-")) {
                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");
+               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));
+               hook_arg1 = "message";
        } else if (use_message) {
                buffer = strstr(use_message_buffer, "\n\n");
                if (!buffer || buffer[2] == '\0')
                        die("commit has empty message");
                strbuf_add(&sb, buffer + 2, strlen(buffer + 2));
+               hook_arg1 = "commit";
+               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));
+               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));
+               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));
+               hook_arg1 = "template";
        }
 
+       /*
+        * This final case does not modify the template message,
+        * it just sets the argument to the prepare-commit-msg hook.
+        */
+       else if (in_merge)
+               hook_arg1 = "merge";
+
        fp = fopen(git_path(commit_editmsg), "w");
        if (fp == NULL)
-               die("could not open %s", git_path(commit_editmsg));
+               die("could not open %s: %s",
+                   git_path(commit_editmsg), strerror(errno));
 
        if (cleanup_mode != CLEANUP_NONE)
                stripspace(&sb, 0);
@@ -417,13 +534,71 @@ static int prepare_log_message(const char *index_file, const char *prefix)
 
        strbuf_release(&sb);
 
-       if (!use_editor) {
+       determine_author_info();
+
+       /* This checks if committer ident is explicitly given */
+       git_committer_info(0);
+       if (use_editor) {
+               char *author_ident;
+               const char *committer_ident;
+
+               if (in_merge)
+                       fprintf(fp,
+                               "#\n"
+                               "# It looks like you may be committing a MERGE.\n"
+                               "# If this is not correct, please remove the file\n"
+                               "#      %s\n"
+                               "# and try again.\n"
+                               "#\n",
+                               git_path("MERGE_HEAD"));
+
+               fprintf(fp,
+                       "\n"
+                       "# Please enter the commit message for your changes.");
+               if (cleanup_mode == CLEANUP_ALL)
+                       fprintf(fp,
+                               " Lines starting\n"
+                               "# with '#' will be ignored, and an empty"
+                               " message aborts the commit.\n");
+               else /* CLEANUP_SPACE, that is. */
+                       fprintf(fp,
+                               " Lines starting\n"
+                               "# with '#' will be kept; you may remove them"
+                               " yourself if you want to.\n"
+                               "# An empty message aborts the commit.\n");
+               if (only_include_assumed)
+                       fprintf(fp, "# %s\n", only_include_assumed);
+
+               author_ident = xstrdup(fmt_name(author_name, author_email));
+               committer_ident = fmt_name(getenv("GIT_COMMITTER_NAME"),
+                                          getenv("GIT_COMMITTER_EMAIL"));
+               if (strcmp(author_ident, committer_ident))
+                       fprintf(fp,
+                               "%s"
+                               "# Author:    %s\n",
+                               ident_shown++ ? "" : "#\n",
+                               author_ident);
+               free(author_ident);
+
+               if (!user_ident_explicitly_given)
+                       fprintf(fp,
+                               "%s"
+                               "# Committer: %s\n",
+                               ident_shown++ ? "" : "#\n",
+                               committer_ident);
+
+               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;
+       } else {
                struct rev_info rev;
                unsigned char sha1[20];
                const char *parent = "HEAD";
 
-               fclose(fp);
-
                if (!active_nr && read_cache() < 0)
                        die("Cannot read index");
 
@@ -431,48 +606,64 @@ static int prepare_log_message(const char *index_file, const char *prefix)
                        parent = "HEAD^1";
 
                if (get_sha1(parent, sha1))
-                       return !!active_nr;
+                       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);
+               }
+       }
 
-               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 */);
+       fclose(fp);
 
-               return !!DIFF_OPT_TST(&rev.diffopt, HAS_CHANGES);
+       if (!commitable && !in_merge && !allow_empty &&
+           !(amend && is_a_merge(head_sha1))) {
+               run_status(stdout, index_file, prefix, 0);
+               unlink(commit_editmsg);
+               return 0;
        }
 
-       if (in_merge)
-               fprintf(fp,
-                       "#\n"
-                       "# It looks like you may be committing a MERGE.\n"
-                       "# If this is not correct, please remove the file\n"
-                       "#      %s\n"
-                       "# and try again.\n"
-                       "#\n",
-                       git_path("MERGE_HEAD"));
-
-       fprintf(fp,
-               "\n"
-               "# Please enter the commit message for your changes.\n"
-               "# (Comment lines starting with '#' will ");
-       if (cleanup_mode == CLEANUP_ALL)
-               fprintf(fp, "not be included)\n");
-       else /* CLEANUP_SPACE, that is. */
-               fprintf(fp, "be kept.\n"
-                       "# You can remove them yourself if you want to)\n");
-       if (only_include_assumed)
-               fprintf(fp, "# %s\n", only_include_assumed);
-
-       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;
+       /*
+        * Re-read the index as pre-commit hook could have updated it,
+        * and write it out as a tree.  We must do this before we invoke
+        * the editor and after we invoke run_status above.
+        */
+       discard_cache();
+       read_cache_from(index_file);
+       if (!active_cache_tree)
+               active_cache_tree = cache_tree();
+       if (cache_tree_update(active_cache_tree,
+                             active_cache, active_nr, 0, 0) < 0) {
+               error("Error building trees");
+               return 0;
+       }
 
-       fclose(fp);
+       if (run_hook(index_file, "prepare-commit-msg",
+                    git_path(commit_editmsg), hook_arg1, hook_arg2, NULL))
+               return 0;
 
-       return commitable;
+       if (use_editor) {
+               char index[PATH_MAX];
+               const char *env[2] = { index, NULL };
+               snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
+               if (launch_editor(git_path(commit_editmsg), NULL, env)) {
+                       fprintf(stderr,
+                       "Please supply the message using either -m or -F option.\n");
+                       exit(1);
+               }
+       }
+
+       if (!no_verify &&
+           run_hook(index_file, "commit-msg", git_path(commit_editmsg), NULL)) {
+               return 0;
+       }
+
+       return 1;
 }
 
 /*
@@ -519,56 +710,22 @@ static int message_is_empty(struct strbuf *sb, int start)
        return 1;
 }
 
-static void determine_author_info(struct strbuf *sb)
-{
-       char *name, *email, *date;
-
-       name = getenv("GIT_AUTHOR_NAME");
-       email = getenv("GIT_AUTHOR_EMAIL");
-       date = getenv("GIT_AUTHOR_DATE");
-
-       if (use_message) {
-               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)
-                       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 (force_author) {
-               const char *lb = strstr(force_author, " <");
-               const char *rb = strchr(force_author, '>');
-
-               if (!lb || !rb)
-                       die("malformed --author parameter");
-               name = xstrndup(force_author, lb - force_author);
-               email = xstrndup(lb + 2, rb - (lb + 2));
-       }
-
-       strbuf_addf(sb, "author %s\n", fmt_ident(name, email, date, IDENT_ERROR_ON_NO_NAME));
-}
-
 static int parse_and_validate_options(int argc, const char *argv[],
-                                     const char * const usage[])
+                                     const char * const usage[],
+                                     const char *prefix)
 {
        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);
 
        if (logfile || message.len || use_message)
                use_editor = 0;
        if (edit_flag)
                use_editor = 1;
+       if (!use_editor)
+               setenv("GIT_EDITOR", ":", 1);
 
        if (get_sha1("HEAD", head_sha1))
                initial_commit = 1;
@@ -640,10 +797,8 @@ static int parse_and_validate_options(int argc, const char *argv[],
                die("No paths with --include/--only does not make sense.");
        if (argc == 0 && only && amend)
                only_include_assumed = "Clever... amending the last one with dirty index.";
-       if (argc > 0 && !also && !only) {
+       if (argc > 0 && !also && !only)
                only_include_assumed = "Explicit paths specified without -i nor -o; assuming --only paths...";
-               also = 0;
-       }
        if (!cleanup_arg || !strcmp(cleanup_arg, "default"))
                cleanup_mode = use_editor ? CLEANUP_ALL : CLEANUP_SPACE;
        else if (!strcmp(cleanup_arg, "verbatim"))
@@ -655,6 +810,17 @@ 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);
+
        if (all && argc > 0)
                die("Paths with -a does not make sense.");
        else if (interactive && argc > 0)
@@ -668,9 +834,12 @@ int cmd_status(int argc, const char **argv, const char *prefix)
        const char *index_file;
        int commitable;
 
-       git_config(git_status_config);
+       git_config(git_status_config, NULL);
+
+       if (wt_status_use_color == -1)
+               wt_status_use_color = git_use_color_default;
 
-       argc = parse_and_validate_options(argc, argv, builtin_status_usage);
+       argc = parse_and_validate_options(argc, argv, builtin_status_usage, prefix);
 
        index_file = prepare_index(argc, argv, prefix);
 
@@ -681,31 +850,6 @@ int cmd_status(int argc, const char **argv, const char *prefix)
        return commitable ? 0 : 1;
 }
 
-static int run_hook(const char *index_file, const char *name, const char *arg)
-{
-       struct child_process hook;
-       const char *argv[3], *env[2];
-       char index[PATH_MAX];
-
-       argv[0] = git_path("hooks/%s", name);
-       argv[1] = arg;
-       argv[2] = NULL;
-       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);
-}
-
 static void print_summary(const char *prefix, const unsigned char *sha1)
 {
        struct rev_info rev;
@@ -727,7 +871,7 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
 
        rev.verbose_header = 1;
        rev.show_root_diff = 1;
-       rev.commit_format = get_commit_format("format:%h: %s");
+       get_commit_format("format:%h: %s", &rev);
        rev.always_show_header = 0;
        rev.diffopt.detect_rename = 1;
        rev.diffopt.rename_limit = 100;
@@ -744,24 +888,12 @@ static void print_summary(const char *prefix, const unsigned char *sha1)
        }
 }
 
-int git_commit_config(const char *k, const char *v)
+static int git_commit_config(const char *k, const char *v, void *cb)
 {
-       if (!strcmp(k, "commit.template")) {
-               if (!v)
-                       return config_error_nonbool(v);
-               template_file = xstrdup(v);
-               return 0;
-       }
+       if (!strcmp(k, "commit.template"))
+               return git_config_string(&template_file, k, v);
 
-       return git_status_config(k, v);
-}
-
-static int is_a_merge(const unsigned char *sha1)
-{
-       struct commit *commit = lookup_commit(sha1);
-       if (!commit || parse_commit(commit))
-               die("could not parse HEAD commit");
-       return !!(commit->parents && commit->parents->next);
+       return git_status_config(k, v, cb);
 }
 
 static const char commit_utf8_warn[] =
@@ -773,10 +905,19 @@ static void add_parent(struct strbuf *sb, const unsigned char *sha1)
 {
        struct object *obj = parse_object(sha1);
        const char *parent = sha1_to_hex(sha1);
+       const char *cp;
+
        if (!obj)
                die("Unable to find commit parent %s", parent);
        if (obj->type != OBJ_COMMIT)
                die("Parent %s isn't a proper commit", parent);
+
+       for (cp = sb->buf; cp && (cp = strstr(cp, "\nparent ")); cp += 8) {
+               if (!memcmp(cp + 8, parent, 40) && cp[48] == '\n') {
+                       error("duplicate parent %s ignored", parent);
+                       return;
+               }
+       }
        strbuf_addf(sb, "parent %s\n", parent);
 }
 
@@ -789,39 +930,19 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
        unsigned char commit_sha1[20];
        struct ref_lock *ref_lock;
 
-       git_config(git_commit_config);
+       git_config(git_commit_config, NULL);
 
-       argc = parse_and_validate_options(argc, argv, builtin_commit_usage);
+       argc = parse_and_validate_options(argc, argv, builtin_commit_usage, prefix);
 
        index_file = prepare_index(argc, argv, prefix);
 
-       if (!no_verify && run_hook(index_file, "pre-commit", NULL)) {
-               rollback_index_files();
-               return 1;
-       }
-
-       if (!prepare_log_message(index_file, prefix) && !in_merge &&
-           !allow_empty && !(amend && is_a_merge(head_sha1))) {
-               run_status(stdout, index_file, 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)) {
                rollback_index_files();
-               unlink(commit_editmsg);
                return 1;
        }
 
-       /*
-        * Re-read the index as pre-commit hook could have updated it,
-        * and write it out as a tree.
-        */
-       discard_cache();
-       read_cache_from(index_file);
-       if (!active_cache_tree)
-               active_cache_tree = cache_tree();
-       if (cache_tree_update(active_cache_tree,
-                             active_cache, active_nr, 0, 0) < 0) {
-               rollback_index_files();
-               die("Error building trees");
-       }
-
        /*
         * The commit object
         */
@@ -867,25 +988,15 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
                strbuf_addf(&sb, "parent %s\n", sha1_to_hex(head_sha1));
        }
 
-       determine_author_info(&sb);
+       strbuf_addf(&sb, "author %s\n",
+                   fmt_ident(author_name, author_email, author_date, IDENT_ERROR_ON_NO_NAME));
        strbuf_addf(&sb, "committer %s\n", git_committer_info(IDENT_ERROR_ON_NO_NAME));
        if (!is_encoding_utf8(git_commit_encoding))
                strbuf_addf(&sb, "encoding %s\n", git_commit_encoding);
        strbuf_addch(&sb, '\n');
 
-       /* Get the commit message and validate it */
+       /* Finally, get the commit message */
        header_len = sb.len;
-       if (use_editor) {
-               char index[PATH_MAX];
-               const char *env[2] = { index, NULL };
-               snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
-               launch_editor(git_path(commit_editmsg), NULL, env);
-       }
-       if (!no_verify &&
-           run_hook(index_file, "commit-msg", git_path(commit_editmsg))) {
-               rollback_index_files();
-               exit(1);
-       }
        if (strbuf_read_file(&sb, git_path(commit_editmsg), 0) < 0) {
                rollback_index_files();
                die("could not read commit message");
@@ -900,7 +1011,8 @@ int cmd_commit(int argc, const char **argv, const char *prefix)
                stripspace(&sb, cleanup_mode == CLEANUP_ALL);
        if (sb.len < header_len || message_is_empty(&sb, header_len)) {
                rollback_index_files();
-               die("no commit message?  aborting commit.");
+               fprintf(stderr, "Aborting commit due to empty commit message.\n");
+               exit(1);
        }
        strbuf_addch(&sb, '\0');
        if (is_encoding_utf8(git_commit_encoding) && !is_utf8(sb.buf))