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
  11/*
  12 * This implements the builtins revert and cherry-pick.
  13 *
  14 * Copyright (c) 2007 Johannes E. Schindelin
  15 *
  16 * Based on git-revert.sh, which is
  17 *
  18 * Copyright (c) 2005 Linus Torvalds
  19 * Copyright (c) 2005 Junio C Hamano
  20 */
  21
  22static const char *revert_usage = "git-revert [--edit | --no-edit] [-n] <commit-ish>";
  23
  24static const char *cherry_pick_usage = "git-cherry-pick [--edit] [-n] [-r] [-x] <commit-ish>";
  25
  26static int edit;
  27static int replay;
  28enum { REVERT, CHERRY_PICK } action;
  29static int no_commit;
  30static struct commit *commit;
  31static int needed_deref;
  32
  33static const char *me;
  34
  35#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
  36
  37static void parse_options(int argc, const char **argv)
  38{
  39        const char *usage_str = action == REVERT ?
  40                revert_usage : cherry_pick_usage;
  41        unsigned char sha1[20];
  42        const char *arg;
  43        int i;
  44
  45        if (argc < 2)
  46                usage(usage_str);
  47
  48        for (i = 1; i < argc - 1; i++) {
  49                arg = argv[i];
  50                if (!strcmp(arg, "-n") || !strcmp(arg, "--no-commit"))
  51                        no_commit = 1;
  52                else if (!strcmp(arg, "-e") || !strcmp(arg, "--edit"))
  53                        edit = 1;
  54                else if (!strcmp(arg, "--no-edit"))
  55                        edit = 0;
  56                else if (!strcmp(arg, "-x") || !strcmp(arg, "--i-really-want-"
  57                                "to-expose-my-private-commit-object-name"))
  58                        replay = 0;
  59                else if (strcmp(arg, "-r"))
  60                        usage(usage_str);
  61        }
  62
  63        arg = argv[argc - 1];
  64        if (get_sha1(arg, sha1))
  65                die ("Cannot find '%s'", arg);
  66        commit = (struct commit *)parse_object(sha1);
  67        if (!commit)
  68                die ("Could not find %s", sha1_to_hex(sha1));
  69        if (commit->object.type == OBJ_TAG) {
  70                commit = (struct commit *)
  71                        deref_tag((struct object *)commit, arg, strlen(arg));
  72                needed_deref = 1;
  73        }
  74        if (commit->object.type != OBJ_COMMIT)
  75                die ("'%s' does not point to a commit", arg);
  76}
  77
  78static char *get_oneline(const char *message)
  79{
  80        char *result;
  81        const char *p = message, *abbrev, *eol;
  82        int abbrev_len, oneline_len;
  83
  84        if (!p)
  85                die ("Could not read commit message of %s",
  86                                sha1_to_hex(commit->object.sha1));
  87        while (*p && (*p != '\n' || p[1] != '\n'))
  88                p++;
  89
  90        if (*p) {
  91                p += 2;
  92                for (eol = p + 1; *eol && *eol != '\n'; eol++)
  93                        ; /* do nothing */
  94        } else
  95                eol = p;
  96        abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  97        abbrev_len = strlen(abbrev);
  98        oneline_len = eol - p;
  99        result = xmalloc(abbrev_len + 5 + oneline_len);
 100        memcpy(result, abbrev, abbrev_len);
 101        memcpy(result + abbrev_len, "... ", 4);
 102        memcpy(result + abbrev_len + 4, p, oneline_len);
 103        result[abbrev_len + 4 + oneline_len] = '\0';
 104        return result;
 105}
 106
 107char *get_encoding(const char *message)
 108{
 109        const char *p = message, *eol;
 110
 111        if (!p)
 112                die ("Could not read commit message of %s",
 113                                sha1_to_hex(commit->object.sha1));
 114        while (*p && *p != '\n') {
 115                for (eol = p + 1; *eol && *eol != '\n'; eol++)
 116                        ; /* do nothing */
 117                if (!prefixcmp(p, "encoding ")) {
 118                        char *result = xmalloc(eol - 8 - p);
 119                        strlcpy(result, p + 9, eol - 8 - p);
 120                        return result;
 121                }
 122                p = eol;
 123                if (*p == '\n')
 124                        p++;
 125        }
 126        return NULL;
 127}
 128
 129struct lock_file msg_file;
 130static int msg_fd;
 131
 132static void add_to_msg(const char *string)
 133{
 134        int len = strlen(string);
 135        if (write_in_full(msg_fd, string, len) < 0)
 136                die ("Could not write to .msg");
 137}
 138
 139static void add_message_to_msg(const char *message)
 140{
 141        const char *p = message;
 142        while (*p && (*p != '\n' || p[1] != '\n'))
 143                p++;
 144
 145        if (!*p)
 146                add_to_msg(sha1_to_hex(commit->object.sha1));
 147
 148        p += 2;
 149        add_to_msg(p);
 150        return;
 151}
 152
 153static void set_author_ident_env(const char *message)
 154{
 155        const char *p = message;
 156        if (!p)
 157                die ("Could not read commit message of %s",
 158                                sha1_to_hex(commit->object.sha1));
 159        while (*p && *p != '\n') {
 160                const char *eol;
 161
 162                for (eol = p; *eol && *eol != '\n'; eol++)
 163                        ; /* do nothing */
 164                if (!prefixcmp(p, "author ")) {
 165                        char *line, *pend, *email, *timestamp;
 166
 167                        p += 7;
 168                        line = xmalloc(eol + 1 - p);
 169                        memcpy(line, p, eol - p);
 170                        line[eol - p] = '\0';
 171                        email = strchr(line, '<');
 172                        if (!email)
 173                                die ("Could not extract author email from %s",
 174                                        sha1_to_hex(commit->object.sha1));
 175                        if (email == line)
 176                                pend = line;
 177                        else
 178                                for (pend = email; pend != line + 1 &&
 179                                                isspace(pend[-1]); pend--);
 180                                        ; /* do nothing */
 181                        *pend = '\0';
 182                        email++;
 183                        timestamp = strchr(email, '>');
 184                        if (!timestamp)
 185                                die ("Could not extract author email from %s",
 186                                        sha1_to_hex(commit->object.sha1));
 187                        *timestamp = '\0';
 188                        for (timestamp++; *timestamp && isspace(*timestamp);
 189                                        timestamp++)
 190                                ; /* do nothing */
 191                        setenv("GIT_AUTHOR_NAME", line, 1);
 192                        setenv("GIT_AUTHOR_EMAIL", email, 1);
 193                        setenv("GIT_AUTHOR_DATE", timestamp, 1);
 194                        free(line);
 195                        return;
 196                }
 197                p = eol;
 198                if (*p == '\n')
 199                        p++;
 200        }
 201        die ("No author information found in %s",
 202                        sha1_to_hex(commit->object.sha1));
 203}
 204
 205static int merge_recursive(const char *base_sha1,
 206                const char *head_sha1, const char *head_name,
 207                const char *next_sha1, const char *next_name)
 208{
 209        char buffer[256];
 210
 211        sprintf(buffer, "GITHEAD_%s", head_sha1);
 212        setenv(buffer, head_name, 1);
 213        sprintf(buffer, "GITHEAD_%s", next_sha1);
 214        setenv(buffer, next_name, 1);
 215
 216        /*
 217         * This three way merge is an interesting one.  We are at
 218         * $head, and would want to apply the change between $commit
 219         * and $prev on top of us (when reverting), or the change between
 220         * $prev and $commit on top of us (when cherry-picking or replaying).
 221         */
 222
 223        return run_command_opt(RUN_COMMAND_NO_STDIN | RUN_GIT_CMD,
 224                        "merge-recursive", base_sha1, "--",
 225                        head_sha1, next_sha1, NULL);
 226}
 227
 228static int revert_or_cherry_pick(int argc, const char **argv)
 229{
 230        unsigned char head[20];
 231        struct commit *base, *next;
 232        int i;
 233        char *oneline, *encoding, *reencoded_message = NULL;
 234        const char *message;
 235
 236        git_config(git_default_config);
 237        me = action == REVERT ? "revert" : "cherry-pick";
 238        setenv(GIT_REFLOG_ACTION, me, 0);
 239        parse_options(argc, argv);
 240
 241        /* this is copied from the shell script, but it's never triggered... */
 242        if (action == REVERT && replay)
 243                die("revert is incompatible with replay");
 244
 245        if (no_commit) {
 246                /*
 247                 * We do not intend to commit immediately.  We just want to
 248                 * merge the differences in.
 249                 */
 250                if (write_tree(head, 0, NULL))
 251                        die ("Your index file is unmerged.");
 252        } else {
 253                struct wt_status s;
 254
 255                if (get_sha1("HEAD", head))
 256                        die ("You do not have a valid HEAD");
 257                wt_status_prepare(&s);
 258                if (s.commitable || s.workdir_dirty)
 259                        die ("Dirty index: cannot %s", me);
 260                discard_cache();
 261        }
 262
 263        if (!commit->parents)
 264                die ("Cannot %s a root commit", me);
 265        if (commit->parents->next)
 266                die ("Cannot %s a multi-parent commit.", me);
 267        if (!(message = commit->buffer))
 268                die ("Cannot get commit message for %s",
 269                                sha1_to_hex(commit->object.sha1));
 270
 271        /*
 272         * "commit" is an existing commit.  We would want to apply
 273         * the difference it introduces since its first parent "prev"
 274         * on top of the current HEAD if we are cherry-pick.  Or the
 275         * reverse of it if we are revert.
 276         */
 277
 278        msg_fd = hold_lock_file_for_update(&msg_file, ".msg", 1);
 279
 280        encoding = get_encoding(message);
 281        if (!encoding)
 282                encoding = "utf-8";
 283        if (!git_commit_encoding)
 284                git_commit_encoding = "utf-8";
 285        if ((reencoded_message = reencode_string(message,
 286                                        git_commit_encoding, encoding)))
 287                message = reencoded_message;
 288
 289        oneline = get_oneline(message);
 290
 291        if (action == REVERT) {
 292                base = commit;
 293                next = commit->parents->item;
 294                add_to_msg("Revert ");
 295                add_to_msg(find_unique_abbrev(commit->object.sha1,
 296                                        DEFAULT_ABBREV));
 297                add_to_msg(oneline);
 298                add_to_msg("\nThis reverts commit ");
 299                add_to_msg(sha1_to_hex(commit->object.sha1));
 300                add_to_msg(".\n");
 301        } else {
 302                base = commit->parents->item;
 303                next = commit;
 304                set_author_ident_env(message);
 305                add_message_to_msg(message);
 306                if (replay) {
 307                        add_to_msg("\n(cherry picked from commit ");
 308                        add_to_msg(sha1_to_hex(commit->object.sha1));
 309                        add_to_msg(")\n");
 310                }
 311        }
 312        if (needed_deref) {
 313                add_to_msg("(original 'git ");
 314                add_to_msg(me);
 315                add_to_msg("' arguments: ");
 316                for (i = 0; i < argc; i++) {
 317                        if (i)
 318                                add_to_msg(" ");
 319                        add_to_msg(argv[i]);
 320                }
 321                add_to_msg(")\n");
 322        }
 323
 324        if (merge_recursive(sha1_to_hex(base->object.sha1),
 325                                sha1_to_hex(head), "HEAD",
 326                                sha1_to_hex(next->object.sha1), oneline))
 327                exit(1);
 328        if (write_tree(head, 0, NULL)) {
 329                const char *target = git_path("MERGE_MSG");
 330                add_to_msg("\nConflicts:\n\n");
 331                read_cache();
 332                for (i = 0; i < active_nr;) {
 333                        struct cache_entry *ce = active_cache[i++];
 334                        if (ce_stage(ce)) {
 335                                add_to_msg("\t");
 336                                add_to_msg(ce->name);
 337                                add_to_msg("\n");
 338                                while (i < active_nr && !strcmp(ce->name,
 339                                                active_cache[i]->name))
 340                                        i++;
 341                        }
 342                }
 343                if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
 344                        die ("Error wrapping up .msg");
 345                unlink(target);
 346                if (rename(".msg", target))
 347                        die ("Could not move .msg to %s", target);
 348                fprintf(stderr, "Automatic %s failed.  "
 349                        "After resolving the conflicts,\n"
 350                        "mark the corrected paths with 'git-add <paths>'\n"
 351                        "and commit the result.\n", me);
 352                if (action == CHERRY_PICK) {
 353                        fprintf(stderr, "You may choose to use the following "
 354                                "when making the commit:\n"
 355                                "GIT_AUTHOR_NAME=\"%s\"\n",
 356                                getenv("GIT_AUTHOR_NAME"));
 357                        fprintf(stderr, "GIT_AUTHOR_EMAIL=\"%s\"\n",
 358                                getenv("GIT_AUTHOR_EMAIL"));
 359                        fprintf(stderr, "GIT_AUTHOR_DATE=\"%s\"\n"
 360                                "export GIT_AUTHOR_NAME GIT_AUTHOR_EMAIL "
 361                                "GIT_AUTHOR_DATE\n",
 362                                getenv("GIT_AUTHOR_DATE"));
 363                }
 364                exit(1);
 365        }
 366        if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
 367                die ("Error wrapping up .msg");
 368        fprintf(stderr, "Finished one %s.\n", me);
 369
 370        /*
 371         *
 372         * If we are cherry-pick, and if the merge did not result in
 373         * hand-editing, we will hit this commit and inherit the original
 374         * author date and name.
 375         * If we are revert, or if our cherry-pick results in a hand merge,
 376         * we had better say that the current user is responsible for that.
 377         */
 378
 379        if (!no_commit) {
 380                if (edit)
 381                        return execl_git_cmd("commit", "-n", "-F", ".msg",
 382                                "-e", NULL);
 383                else
 384                        return execl_git_cmd("commit", "-n", "-F", ".msg",
 385                                NULL);
 386        }
 387        if (reencoded_message)
 388                free(reencoded_message);
 389
 390        return 0;
 391}
 392
 393int cmd_revert(int argc, const char **argv, const char *prefix)
 394{
 395        if (isatty(0))
 396                edit = 1;
 397        action = REVERT;
 398        return revert_or_cherry_pick(argc, argv);
 399}
 400
 401int cmd_cherry_pick(int argc, const char **argv, const char *prefix)
 402{
 403        replay = 1;
 404        action = CHERRY_PICK;
 405        return revert_or_cherry_pick(argc, argv);
 406}