Andrew's git - gitweb.git/blob

   1#include "cache.h"
   2#include "builtin.h"
   3#include "object.h"
   4#include "commit.h"
   5#include "tag.h"
   6#include "wt-status.h"
   7#include "run-command.h"
   8#include "exec_cmd.h"
   9#include "utf8.h"
  10#include "parse-options.h"
  11
  12/*
  13 * This implements the builtins revert and cherry-pick.
  14 *
  15 * Copyright (c) 2007 Johannes E. Schindelin
  16 *
  17 * Based on git-revert.sh, which is
  18 *
  19 * Copyright (c) 2005 Linus Torvalds
  20 * Copyright (c) 2005 Junio C Hamano
  21 */
  22
  23static const char * const revert_usage[] = {
  24        "git-revert [options] <commit-ish>",
  25        NULL
  26};
  27
  28static const char * const cherry_pick_usage[] = {
  29        "git-cherry-pick [options] <commit-ish>",
  30        NULL
  31};
  32
  33static int edit, no_replay, no_commit, needed_deref;
  34static enum { REVERT, CHERRY_PICK } action;
  35static struct commit *commit;
  36
  37static const char *me;
  38
  39#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  40
  41static void parse_args(int argc, const char **argv)
  42{
  43        const char * const * usage_str =
  44                action == REVERT ?  revert_usage : cherry_pick_usage;
  45        unsigned char sha1[20];
  46        const char *arg;
  47        int noop;
  48        struct option options[] = {
  49                OPT_BOOLEAN('n', "no-commit", &no_commit, "don't automatically commit"),
  50                OPT_BOOLEAN('e', "edit", &edit, "edit the commit message"),
  51                OPT_BOOLEAN('x', NULL, &no_replay, "append commit name when cherry-picking"),
  52                OPT_BOOLEAN('r', NULL, &noop, "no-op (backward compatibility)"),
  53                OPT_END(),
  54        };
  55
  56        if (parse_options(argc, argv, options, usage_str, 0) != 1)
  57                usage_with_options(usage_str, options);
  58        arg = argv[0];
  59        if (get_sha1(arg, sha1))
  60                die ("Cannot find '%s'", arg);
  61        commit = (struct commit *)parse_object(sha1);
  62        if (!commit)
  63                die ("Could not find %s", sha1_to_hex(sha1));
  64        if (commit->object.type == OBJ_TAG) {
  65                commit = (struct commit *)
  66                        deref_tag((struct object *)commit, arg, strlen(arg));
  67                needed_deref = 1;
  68        }
  69        if (commit->object.type != OBJ_COMMIT)
  70                die ("'%s' does not point to a commit", arg);
  71}
  72
  73static char *get_oneline(const char *message)
  74{
  75        char *result;
  76        const char *p = message, *abbrev, *eol;
  77        int abbrev_len, oneline_len;
  78
  79        if (!p)
  80                die ("Could not read commit message of %s",
  81                                sha1_to_hex(commit->object.sha1));
  82        while (*p && (*p != '\n' || p[1] != '\n'))
  83                p++;
  84
  85        if (*p) {
  86                p += 2;
  87                for (eol = p + 1; *eol && *eol != '\n'; eol++)
  88                        ; /* do nothing */
  89        } else
  90                eol = p;
  91        abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  92        abbrev_len = strlen(abbrev);
  93        oneline_len = eol - p;
  94        result = xmalloc(abbrev_len + 5 + oneline_len);
  95        memcpy(result, abbrev, abbrev_len);
  96        memcpy(result + abbrev_len, "... ", 4);
  97        memcpy(result + abbrev_len + 4, p, oneline_len);
  98        result[abbrev_len + 4 + oneline_len] = '\0';
  99        return result;
 100}
 101
 102static char *get_encoding(const char *message)
 103{
 104        const char *p = message, *eol;
 105
 106        if (!p)
 107                die ("Could not read commit message of %s",
 108                                sha1_to_hex(commit->object.sha1));
 109        while (*p && *p != '\n') {
 110                for (eol = p + 1; *eol && *eol != '\n'; eol++)
 111                        ; /* do nothing */
 112                if (!prefixcmp(p, "encoding ")) {
 113                        char *result = xmalloc(eol - 8 - p);
 114                        strlcpy(result, p + 9, eol - 8 - p);
 115                        return result;
 116                }
 117                p = eol;
 118                if (*p == '\n')
 119                        p++;
 120        }
 121        return NULL;
 122}
 123
 124static struct lock_file msg_file;
 125static int msg_fd;
 126
 127static void add_to_msg(const char *string)
 128{
 129        int len = strlen(string);
 130        if (write_in_full(msg_fd, string, len) < 0)
 131                die ("Could not write to MERGE_MSG");
 132}
 133
 134static void add_message_to_msg(const char *message)
 135{
 136        const char *p = message;
 137        while (*p && (*p != '\n' || p[1] != '\n'))
 138                p++;
 139
 140        if (!*p)
 141                add_to_msg(sha1_to_hex(commit->object.sha1));
 142
 143        p += 2;
 144        add_to_msg(p);
 145        return;
 146}
 147
 148static void set_author_ident_env(const char *message)
 149{
 150        const char *p = message;
 151        if (!p)
 152                die ("Could not read commit message of %s",
 153                                sha1_to_hex(commit->object.sha1));
 154        while (*p && *p != '\n') {
 155                const char *eol;
 156
 157                for (eol = p; *eol && *eol != '\n'; eol++)
 158                        ; /* do nothing */
 159                if (!prefixcmp(p, "author ")) {
 160                        char *line, *pend, *email, *timestamp;
 161
 162                        p += 7;
 163                        line = xmemdupz(p, eol - p);
 164                        email = strchr(line, '<');
 165                        if (!email)
 166                                die ("Could not extract author email from %s",
 167                                        sha1_to_hex(commit->object.sha1));
 168                        if (email == line)
 169                                pend = line;
 170                        else
 171                                for (pend = email; pend != line + 1 &&
 172                                                isspace(pend[-1]); pend--);
 173                                        ; /* do nothing */
 174                        *pend = '\0';
 175                        email++;
 176                        timestamp = strchr(email, '>');
 177                        if (!timestamp)
 178                                die ("Could not extract author email from %s",
 179                                        sha1_to_hex(commit->object.sha1));
 180                        *timestamp = '\0';
 181                        for (timestamp++; *timestamp && isspace(*timestamp);
 182                                        timestamp++)
 183                                ; /* do nothing */
 184                        setenv("GIT_AUTHOR_NAME", line, 1);
 185                        setenv("GIT_AUTHOR_EMAIL", email, 1);
 186                        setenv("GIT_AUTHOR_DATE", timestamp, 1);
 187                        free(line);
 188                        return;
 189                }
 190                p = eol;
 191                if (*p == '\n')
 192                        p++;
 193        }
 194        die ("No author information found in %s",
 195                        sha1_to_hex(commit->object.sha1));
 196}
 197
 198static int merge_recursive(const char *base_sha1,
 199                const char *head_sha1, const char *head_name,
 200                const char *next_sha1, const char *next_name)
 201{
 202        char buffer[256];
 203        const char *argv[6];
 204
 205        sprintf(buffer, "GITHEAD_%s", head_sha1);
 206        setenv(buffer, head_name, 1);
 207        sprintf(buffer, "GITHEAD_%s", next_sha1);
 208        setenv(buffer, next_name, 1);
 209
 210        /*
 211         * This three way merge is an interesting one.  We are at
 212         * $head, and would want to apply the change between $commit
 213         * and $prev on top of us (when reverting), or the change between
 214         * $prev and $commit on top of us (when cherry-picking or replaying).
 215         */
 216        argv[0] = "merge-recursive";
 217        argv[1] = base_sha1;
 218        argv[2] = "--";
 219        argv[3] = head_sha1;
 220        argv[4] = next_sha1;
 221        argv[5] = NULL;
 222
 223        return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
 224}
 225
 226static int revert_or_cherry_pick(int argc, const char **argv)
 227{
 228        unsigned char head[20];
 229        struct commit *base, *next;
 230        int i;
 231        char *oneline, *reencoded_message = NULL;
 232        const char *message, *encoding;
 233        const char *defmsg = xstrdup(git_path("MERGE_MSG"));
 234
 235        git_config(git_default_config);
 236        me = action == REVERT ? "revert" : "cherry-pick";
 237        setenv(GIT_REFLOG_ACTION, me, 0);
 238        parse_args(argc, argv);
 239
 240        /* this is copied from the shell script, but it's never triggered... */
 241        if (action == REVERT && !no_replay)
 242                die("revert is incompatible with replay");
 243
 244        if (no_commit) {
 245                /*
 246                 * We do not intend to commit immediately.  We just want to
 247                 * merge the differences in.
 248                 */
 249                if (write_tree(head, 0, NULL))
 250                        die ("Your index file is unmerged.");
 251        } else {
 252                struct wt_status s;
 253
 254                if (get_sha1("HEAD", head))
 255                        die ("You do not have a valid HEAD");
 256                wt_status_prepare(&s);
 257                if (s.commitable || s.workdir_dirty)
 258                        die ("Dirty index: cannot %s", me);
 259                discard_cache();
 260        }
 261
 262        if (!commit->parents)
 263                die ("Cannot %s a root commit", me);
 264        if (commit->parents->next)
 265                die ("Cannot %s a multi-parent commit.", me);
 266        if (!(message = commit->buffer))
 267                die ("Cannot get commit message for %s",
 268                                sha1_to_hex(commit->object.sha1));
 269
 270        /*
 271         * "commit" is an existing commit.  We would want to apply
 272         * the difference it introduces since its first parent "prev"
 273         * on top of the current HEAD if we are cherry-pick.  Or the
 274         * reverse of it if we are revert.
 275         */
 276
 277        msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
 278
 279        encoding = get_encoding(message);
 280        if (!encoding)
 281                encoding = "utf-8";
 282        if (!git_commit_encoding)
 283                git_commit_encoding = "utf-8";
 284        if ((reencoded_message = reencode_string(message,
 285                                        git_commit_encoding, encoding)))
 286                message = reencoded_message;
 287
 288        oneline = get_oneline(message);
 289
 290        if (action == REVERT) {
 291                char *oneline_body = strchr(oneline, ' ');
 292
 293                base = commit;
 294                next = commit->parents->item;
 295                add_to_msg("Revert \"");
 296                add_to_msg(oneline_body + 1);
 297                add_to_msg("\"\n\nThis reverts commit ");
 298                add_to_msg(sha1_to_hex(commit->object.sha1));
 299                add_to_msg(".\n");
 300        } else {
 301                base = commit->parents->item;
 302                next = commit;
 303                set_author_ident_env(message);
 304                add_message_to_msg(message);
 305                if (no_replay) {
 306                        add_to_msg("(cherry picked from commit ");
 307                        add_to_msg(sha1_to_hex(commit->object.sha1));
 308                        add_to_msg(")\n");
 309                }
 310        }
 311        if (needed_deref) {
 312                add_to_msg("(original 'git ");
 313                add_to_msg(me);
 314                add_to_msg("' arguments: ");
 315                for (i = 0; i < argc; i++) {
 316                        if (i)
 317                                add_to_msg(" ");
 318                        add_to_msg(argv[i]);
 319                }
 320                add_to_msg(")\n");
 321        }
 322
 323        if (merge_recursive(sha1_to_hex(base->object.sha1),
 324                                sha1_to_hex(head), "HEAD",
 325                                sha1_to_hex(next->object.sha1), oneline) ||
 326                        write_tree(head, 0, NULL)) {
 327                add_to_msg("\nConflicts:\n\n");
 328                read_cache();
 329                for (i = 0; i < active_nr;) {
 330                        struct cache_entry *ce = active_cache[i++];
 331                        if (ce_stage(ce)) {
 332                                add_to_msg("\t");
 333                                add_to_msg(ce->name);
 334                                add_to_msg("\n");
 335                                while (i < active_nr && !strcmp(ce->name,
 336                                                active_cache[i]->name))
 337                                        i++;
 338                        }
 339                }
 340                if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
 341                        die ("Error wrapping up %s", defmsg);
 342                fprintf(stderr, "Automatic %s failed.  "
 343                        "After resolving the conflicts,\n"
 344                        "mark the corrected paths with 'git add <paths>' "
 345                        "and commit the result.\n", me);
 346                if (action == CHERRY_PICK) {
 347                        fprintf(stderr, "When commiting, use the option "
 348                                "'-c %s' to retain authorship and message.\n",
 349                                find_unique_abbrev(commit->object.sha1,
 350                                        DEFAULT_ABBREV));
 351                }
 352                exit(1);
 353        }
 354        if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
 355                die ("Error wrapping up %s", defmsg);
 356        fprintf(stderr, "Finished one %s.\n", me);
 357
 358        /*
 359         *
 360         * If we are cherry-pick, and if the merge did not result in
 361         * hand-editing, we will hit this commit and inherit the original
 362         * author date and name.
 363         * If we are revert, or if our cherry-pick results in a hand merge,
 364         * we had better say that the current user is responsible for that.
 365         */
 366
 367        if (!no_commit) {
 368                if (edit)
 369                        return execl_git_cmd("commit", "-n", NULL);
 370                else
 371                        return execl_git_cmd("commit", "-n", "-F", defmsg, NULL);
 372        }
 373        if (reencoded_message)
 374                free(reencoded_message);
 375
 376        return 0;
 377}
 378
 379int cmd_revert(int argc, const char **argv, const char *prefix)
 380{
 381        if (isatty(0))
 382                edit = 1;
 383        no_replay = 1;
 384        action = REVERT;
 385        return revert_or_cherry_pick(argc, argv);
 386}
 387
 388int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 389{
 390        no_replay = 0;
 391        action = CHERRY_PICK;
 392        return revert_or_cherry_pick(argc, argv);
 393}