compat: Add simplified merge sort implementation from glibc
[gitweb.git] / builtin-revert.c
index 94e77771d24decc60c50adf0cd3ab272ce36d3f2..358af537476b0b558989f27fe60627af6977635b 100644 (file)
@@ -7,6 +7,7 @@
 #include "run-command.h"
 #include "exec_cmd.h"
 #include "utf8.h"
+#include "parse-options.h"
 
 /*
  * This implements the builtins revert and cherry-pick.
  * Copyright (c) 2005 Junio C Hamano
  */
 
-static const char *revert_usage = "git-revert [--edit | --no-edit] [-n] <commit-ish>";
+static const char * const revert_usage[] = {
+       "git-revert [options] <commit-ish>",
+       NULL
+};
 
-static const char *cherry_pick_usage = "git-cherry-pick [--edit] [-n] [-r] [-x] <commit-ish>";
+static const char * const cherry_pick_usage[] = {
+       "git-cherry-pick [options] <commit-ish>",
+       NULL
+};
 
-static int edit;
-static int replay;
+static int edit, no_replay, no_commit, mainline;
 static enum { REVERT, CHERRY_PICK } action;
-static int no_commit;
 static struct commit *commit;
-static int needed_deref;
 
 static const char *me;
 
 #define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
 
-static void parse_options(int argc, const char **argv)
+static void parse_args(int argc, const char **argv)
 {
-       const char *usage_str = action == REVERT ?
-               revert_usage : cherry_pick_usage;
+       const char * const * usage_str =
+               action == REVERT ?  revert_usage : cherry_pick_usage;
        unsigned char sha1[20];
        const char *arg;
-       int i;
+       int noop;
+       struct option options[] = {
+               OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
+               OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
+               OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
+               OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
+               OPT_INTEGER('m', "mainline", &mainline, "parent number"),
+               OPT_END(),
+       };
+
+       if (parse_options(argc, argv, options, usage_str, 0) != 1)
+               usage_with_options(usage_str, options);
+       arg = argv[0];
 
-       if (argc < 2)
-               usage(usage_str);
-
-       for (i = 1; i < argc; i++) {
-               arg = argv[i];
-               if (arg[0] != '-')
-                       break;
-               if (!strcmp(arg, "-n") || !strcmp(arg, "--no-commit"))
-                       no_commit = 1;
-               else if (!strcmp(arg, "-e") || !strcmp(arg, "--edit"))
-                       edit = 1;
-               else if (!strcmp(arg, "--no-edit"))
-                       edit = 0;
-               else if (!strcmp(arg, "-x") || !strcmp(arg, "--i-really-want-"
-                               "to-expose-my-private-commit-object-name"))
-                       replay = 0;
-               else if (strcmp(arg, "-r"))
-                       usage(usage_str);
-       }
-       if (i != argc - 1)
-               usage(usage_str);
-       arg = argv[argc - 1];
        if (get_sha1(arg, sha1))
                die ("Cannot find '%s'", arg);
        commit = (struct commit *)parse_object(sha1);
@@ -72,7 +66,6 @@ static void parse_options(int argc, const char **argv)
        if (commit->object.type == OBJ_TAG) {
                commit = (struct commit *)
                        deref_tag((struct object *)commit, arg, strlen(arg));
-               needed_deref = 1;
        }
        if (commit->object.type != OBJ_COMMIT)
                die ("'%s' does not point to a commit", arg);
@@ -168,9 +161,7 @@ static void set_author_ident_env(const char *message)
                        char *line, *pend, *email, *timestamp;
 
                        p += 7;
-                       line = xmalloc(eol + 1 - p);
-                       memcpy(line, p, eol - p);
-                       line[eol - p] = '\0';
+                       line = xmemdupz(p, eol - p);
                        email = strchr(line, '<');
                        if (!email)
                                die ("Could not extract author email from %s",
@@ -233,10 +224,31 @@ static int merge_recursive(const char *base_sha1,
        return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
 }
 
+static char *help_msg(const unsigned char *sha1)
+{
+       static char helpbuf[1024];
+       char *msg = getenv("GIT_CHERRY_PICK_HELP");
+
+       if (msg)
+               return msg;
+
+       strcpy(helpbuf, "  After resolving the conflicts,\n"
+              "mark the corrected paths with 'git add <paths>' "
+              "or 'git rm <paths>' and commit the result.");
+
+       if (action == CHERRY_PICK) {
+               sprintf(helpbuf + strlen(helpbuf),
+                       "\nWhen commiting, use the option "
+                       "'-c %s' to retain authorship and message.",
+                       find_unique_abbrev(sha1, DEFAULT_ABBREV));
+       }
+       return helpbuf;
+}
+
 static int revert_or_cherry_pick(int argc, const char **argv)
 {
        unsigned char head[20];
-       struct commit *base, *next;
+       struct commit *base, *next, *parent;
        int i;
        char *oneline, *reencoded_message = NULL;
        const char *message, *encoding;
@@ -245,16 +257,18 @@ static int revert_or_cherry_pick(int argc, const char **argv)
        git_config(git_default_config);
        me = action == REVERT ? "revert" : "cherry-pick";
        setenv(GIT_REFLOG_ACTION, me, 0);
-       parse_options(argc, argv);
+       parse_args(argc, argv);
 
        /* this is copied from the shell script, but it's never triggered... */
-       if (action == REVERT && replay)
+       if (action == REVERT && !no_replay)
                die("revert is incompatible with replay");
 
        if (no_commit) {
                /*
                 * We do not intend to commit immediately.  We just want to
-                * merge the differences in.
+                * merge the differences in, so let's compute the tree
+                * that represents the "current" state for merge-recursive
+                * to work on.
                 */
                if (write_tree(head, 0, NULL))
                        die ("Your index file is unmerged.");
@@ -271,8 +285,29 @@ static int revert_or_cherry_pick(int argc, const char **argv)
 
        if (!commit->parents)
                die ("Cannot %s a root commit", me);
-       if (commit->parents->next)
-               die ("Cannot %s a multi-parent commit.", me);
+       if (commit->parents->next) {
+               /* Reverting or cherry-picking a merge commit */
+               int cnt;
+               struct commit_list *p;
+
+               if (!mainline)
+                       die("Commit %s is a merge but no -m option was given.",
+                           sha1_to_hex(commit->object.sha1));
+
+               for (cnt = 1, p = commit->parents;
+                    cnt != mainline && p;
+                    cnt++)
+                       p = p->next;
+               if (cnt != mainline || !p)
+                       die("Commit %s does not have parent %d",
+                           sha1_to_hex(commit->object.sha1), mainline);
+               parent = p->item;
+       } else if (0 < mainline)
+               die("Mainline was specified but commit %s is not a merge.",
+                   sha1_to_hex(commit->object.sha1));
+       else
+               parent = commit->parents->item;
+
        if (!(message = commit->buffer))
                die ("Cannot get commit message for %s",
                                sha1_to_hex(commit->object.sha1));
@@ -301,34 +336,23 @@ static int revert_or_cherry_pick(int argc, const char **argv)
                char *oneline_body = strchr(oneline, ' ');
 
                base = commit;
-               next = commit->parents->item;
+               next = parent;
                add_to_msg("Revert \"");
                add_to_msg(oneline_body + 1);
                add_to_msg("\"\n\nThis reverts commit ");
                add_to_msg(sha1_to_hex(commit->object.sha1));
                add_to_msg(".\n");
        } else {
-               base = commit->parents->item;
+               base = parent;
                next = commit;
                set_author_ident_env(message);
                add_message_to_msg(message);
-               if (!replay) {
+               if (no_replay) {
                        add_to_msg("(cherry picked from commit ");
                        add_to_msg(sha1_to_hex(commit->object.sha1));
                        add_to_msg(")\n");
                }
        }
-       if (needed_deref) {
-               add_to_msg("(original 'git ");
-               add_to_msg(me);
-               add_to_msg("' arguments: ");
-               for (i = 0; i < argc; i++) {
-                       if (i)
-                               add_to_msg(" ");
-                       add_to_msg(argv[i]);
-               }
-               add_to_msg(")\n");
-       }
 
        if (merge_recursive(sha1_to_hex(base->object.sha1),
                                sha1_to_hex(head), "HEAD",
@@ -347,21 +371,13 @@ static int revert_or_cherry_pick(int argc, const char **argv)
                                        i++;
                        }
                }
-               if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
+               if (commit_lock_file(&msg_file) < 0)
                        die ("Error wrapping up %s", defmsg);
-               fprintf(stderr, "Automatic %s failed.  "
-                       "After resolving the conflicts,\n"
-                       "mark the corrected paths with 'git add <paths>' "
-                       "and commit the result.\n", me);
-               if (action == CHERRY_PICK) {
-                       fprintf(stderr, "When commiting, use the option "
-                               "'-c %s' to retain authorship and message.\n",
-                               find_unique_abbrev(commit->object.sha1,
-                                       DEFAULT_ABBREV));
-               }
+               fprintf(stderr, "Automatic %s failed.%s\n",
+                       me, help_msg(commit->object.sha1));
                exit(1);
        }
-       if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
+       if (commit_lock_file(&msg_file) < 0)
                die ("Error wrapping up %s", defmsg);
        fprintf(stderr, "Finished one %s.\n", me);
 
@@ -390,13 +406,14 @@ int cmd_revert(int argc, const char **argv, const char *prefix)
 {
        if (isatty(0))
                edit = 1;
+       no_replay = 1;
        action = REVERT;
        return revert_or_cherry_pick(argc, argv);
 }
 
 int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 {
-       replay = 1;
+       no_replay = 0;
        action = CHERRY_PICK;
        return revert_or_cherry_pick(argc, argv);
 }