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, mainline;
  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_INTEGER('m', "mainline", &mainline, "parent number"),
  54                OPT_END(),
  55        };
  56
  57        if (parse_options(argc, argv, options, usage_str, 0) != 1)
  58                usage_with_options(usage_str, options);
  59        arg = argv[0];
  60
  61        if (get_sha1(arg, sha1))
  62                die ("Cannot find '%s'", arg);
  63        commit = (struct commit *)parse_object(sha1);
  64        if (!commit)
  65                die ("Could not find %s", sha1_to_hex(sha1));
  66        if (commit->object.type == OBJ_TAG) {
  67                commit = (struct commit *)
  68                        deref_tag((struct object *)commit, arg, strlen(arg));
  69        }
  70        if (commit->object.type != OBJ_COMMIT)
  71                die ("'%s' does not point to a commit", arg);
  72}
  73
  74static char *get_oneline(const char *message)
  75{
  76        char *result;
  77        const char *p = message, *abbrev, *eol;
  78        int abbrev_len, oneline_len;
  79
  80        if (!p)
  81                die ("Could not read commit message of %s",
  82                                sha1_to_hex(commit->object.sha1));
  83        while (*p && (*p != '\n' || p[1] != '\n'))
  84                p++;
  85
  86        if (*p) {
  87                p += 2;
  88                for (eol = p + 1; *eol && *eol != '\n'; eol++)
  89                        ; /* do nothing */
  90        } else
  91                eol = p;
  92        abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV);
  93        abbrev_len = strlen(abbrev);
  94        oneline_len = eol - p;
  95        result = xmalloc(abbrev_len + 5 + oneline_len);
  96        memcpy(result, abbrev, abbrev_len);
  97        memcpy(result + abbrev_len, "... ", 4);
  98        memcpy(result + abbrev_len + 4, p, oneline_len);
  99        result[abbrev_len + 4 + oneline_len] = '\0';
 100        return result;
 101}
 102
 103static char *get_encoding(const char *message)
 104{
 105        const char *p = message, *eol;
 106
 107        if (!p)
 108                die ("Could not read commit message of %s",
 109                                sha1_to_hex(commit->object.sha1));
 110        while (*p && *p != '\n') {
 111                for (eol = p + 1; *eol && *eol != '\n'; eol++)
 112                        ; /* do nothing */
 113                if (!prefixcmp(p, "encoding ")) {
 114                        char *result = xmalloc(eol - 8 - p);
 115                        strlcpy(result, p + 9, eol - 8 - p);
 116                        return result;
 117                }
 118                p = eol;
 119                if (*p == '\n')
 120                        p++;
 121        }
 122        return NULL;
 123}
 124
 125static struct lock_file msg_file;
 126static int msg_fd;
 127
 128static void add_to_msg(const char *string)
 129{
 130        int len = strlen(string);
 131        if (write_in_full(msg_fd, string, len) < 0)
 132                die ("Could not write to MERGE_MSG");
 133}
 134
 135static void add_message_to_msg(const char *message)
 136{
 137        const char *p = message;
 138        while (*p && (*p != '\n' || p[1] != '\n'))
 139                p++;
 140
 141        if (!*p)
 142                add_to_msg(sha1_to_hex(commit->object.sha1));
 143
 144        p += 2;
 145        add_to_msg(p);
 146        return;
 147}
 148
 149static void set_author_ident_env(const char *message)
 150{
 151        const char *p = message;
 152        if (!p)
 153                die ("Could not read commit message of %s",
 154                                sha1_to_hex(commit->object.sha1));
 155        while (*p && *p != '\n') {
 156                const char *eol;
 157
 158                for (eol = p; *eol && *eol != '\n'; eol++)
 159                        ; /* do nothing */
 160                if (!prefixcmp(p, "author ")) {
 161                        char *line, *pend, *email, *timestamp;
 162
 163                        p += 7;
 164                        line = xmemdupz(p, eol - p);
 165                        email = strchr(line, '<');
 166                        if (!email)
 167                                die ("Could not extract author email from %s",
 168                                        sha1_to_hex(commit->object.sha1));
 169                        if (email == line)
 170                                pend = line;
 171                        else
 172                                for (pend = email; pend != line + 1 &&
 173                                                isspace(pend[-1]); pend--);
 174                                        ; /* do nothing */
 175                        *pend = '\0';
 176                        email++;
 177                        timestamp = strchr(email, '>');
 178                        if (!timestamp)
 179                                die ("Could not extract author email from %s",
 180                                        sha1_to_hex(commit->object.sha1));
 181                        *timestamp = '\0';
 182                        for (timestamp++; *timestamp && isspace(*timestamp);
 183                                        timestamp++)
 184                                ; /* do nothing */
 185                        setenv("GIT_AUTHOR_NAME", line, 1);
 186                        setenv("GIT_AUTHOR_EMAIL", email, 1);
 187                        setenv("GIT_AUTHOR_DATE", timestamp, 1);
 188                        free(line);
 189                        return;
 190                }
 191                p = eol;
 192                if (*p == '\n')
 193                        p++;
 194        }
 195        die ("No author information found in %s",
 196                        sha1_to_hex(commit->object.sha1));
 197}
 198
 199static int merge_recursive(const char *base_sha1,
 200                const char *head_sha1, const char *head_name,
 201                const char *next_sha1, const char *next_name)
 202{
 203        char buffer[256];
 204        const char *argv[6];
 205
 206        sprintf(buffer, "GITHEAD_%s", head_sha1);
 207        setenv(buffer, head_name, 1);
 208        sprintf(buffer, "GITHEAD_%s", next_sha1);
 209        setenv(buffer, next_name, 1);
 210
 211        /*
 212         * This three way merge is an interesting one.  We are at
 213         * $head, and would want to apply the change between $commit
 214         * and $prev on top of us (when reverting), or the change between
 215         * $prev and $commit on top of us (when cherry-picking or replaying).
 216         */
 217        argv[0] = "merge-recursive";
 218        argv[1] = base_sha1;
 219        argv[2] = "--";
 220        argv[3] = head_sha1;
 221        argv[4] = next_sha1;
 222        argv[5] = NULL;
 223
 224        return run_command_v_opt(argv, RUN_COMMAND_NO_STDIN | RUN_GIT_CMD);
 225}
 226
 227static int revert_or_cherry_pick(int argc, const char **argv)
 228{
 229        unsigned char head[20];
 230        struct commit *base, *next, *parent;
 231        int i;
 232        char *oneline, *reencoded_message = NULL;
 233        const char *message, *encoding;
 234        const char *defmsg = xstrdup(git_path("MERGE_MSG"));
 235
 236        git_config(git_default_config);
 237        me = action == REVERT ? "revert" : "cherry-pick";
 238        setenv(GIT_REFLOG_ACTION, me, 0);
 239        parse_args(argc, argv);
 240
 241        /* this is copied from the shell script, but it's never triggered... */
 242        if (action == REVERT && !no_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, so let's compute the tree
 249                 * that represents the "current" state for merge-recursive
 250                 * to work on.
 251                 */
 252                if (write_tree(head, 0, NULL))
 253                        die ("Your index file is unmerged.");
 254        } else {
 255                struct wt_status s;
 256
 257                if (get_sha1("HEAD", head))
 258                        die ("You do not have a valid HEAD");
 259                wt_status_prepare(&s);
 260                if (s.commitable)
 261                        die ("Dirty index: cannot %s", me);
 262                discard_cache();
 263        }
 264
 265        if (!commit->parents)
 266                die ("Cannot %s a root commit", me);
 267        if (commit->parents->next) {
 268                /* Reverting or cherry-picking a merge commit */
 269                int cnt;
 270                struct commit_list *p;
 271
 272                if (!mainline)
 273                        die("Commit %s is a merge but no -m option was given.",
 274                            sha1_to_hex(commit->object.sha1));
 275
 276                for (cnt = 1, p = commit->parents;
 277                     cnt != mainline && p;
 278                     cnt++)
 279                        p = p->next;
 280                if (cnt != mainline || !p)
 281                        die("Commit %s does not have parent %d",
 282                            sha1_to_hex(commit->object.sha1), mainline);
 283                parent = p->item;
 284        } else if (0 < mainline)
 285                die("Mainline was specified but commit %s is not a merge.",
 286                    sha1_to_hex(commit->object.sha1));
 287        else
 288                parent = commit->parents->item;
 289
 290        if (!(message = commit->buffer))
 291                die ("Cannot get commit message for %s",
 292                                sha1_to_hex(commit->object.sha1));
 293
 294        /*
 295         * "commit" is an existing commit.  We would want to apply
 296         * the difference it introduces since its first parent "prev"
 297         * on top of the current HEAD if we are cherry-pick.  Or the
 298         * reverse of it if we are revert.
 299         */
 300
 301        msg_fd = hold_lock_file_for_update(&msg_file, defmsg, 1);
 302
 303        encoding = get_encoding(message);
 304        if (!encoding)
 305                encoding = "utf-8";
 306        if (!git_commit_encoding)
 307                git_commit_encoding = "utf-8";
 308        if ((reencoded_message = reencode_string(message,
 309                                        git_commit_encoding, encoding)))
 310                message = reencoded_message;
 311
 312        oneline = get_oneline(message);
 313
 314        if (action == REVERT) {
 315                char *oneline_body = strchr(oneline, ' ');
 316
 317                base = commit;
 318                next = parent;
 319                add_to_msg("Revert \"");
 320                add_to_msg(oneline_body + 1);
 321                add_to_msg("\"\n\nThis reverts commit ");
 322                add_to_msg(sha1_to_hex(commit->object.sha1));
 323                add_to_msg(".\n");
 324        } else {
 325                base = parent;
 326                next = commit;
 327                set_author_ident_env(message);
 328                add_message_to_msg(message);
 329                if (no_replay) {
 330                        add_to_msg("(cherry picked from commit ");
 331                        add_to_msg(sha1_to_hex(commit->object.sha1));
 332                        add_to_msg(")\n");
 333                }
 334        }
 335
 336        if (merge_recursive(sha1_to_hex(base->object.sha1),
 337                                sha1_to_hex(head), "HEAD",
 338                                sha1_to_hex(next->object.sha1), oneline) ||
 339                        write_tree(head, 0, NULL)) {
 340                add_to_msg("\nConflicts:\n\n");
 341                read_cache();
 342                for (i = 0; i < active_nr;) {
 343                        struct cache_entry *ce = active_cache[i++];
 344                        if (ce_stage(ce)) {
 345                                add_to_msg("\t");
 346                                add_to_msg(ce->name);
 347                                add_to_msg("\n");
 348                                while (i < active_nr && !strcmp(ce->name,
 349                                                active_cache[i]->name))
 350                                        i++;
 351                        }
 352                }
 353                if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
 354                        die ("Error wrapping up %s", defmsg);
 355                fprintf(stderr, "Automatic %s failed.  "
 356                        "After resolving the conflicts,\n"
 357                        "mark the corrected paths with 'git add <paths>' "
 358                        "and commit the result.\n", me);
 359                if (action == CHERRY_PICK) {
 360                        fprintf(stderr, "When commiting, use the option "
 361                                "'-c %s' to retain authorship and message.\n",
 362                                find_unique_abbrev(commit->object.sha1,
 363                                        DEFAULT_ABBREV));
 364                }
 365                exit(1);
 366        }
 367        if (close(msg_fd) || commit_lock_file(&msg_file) < 0)
 368                die ("Error wrapping up %s", defmsg);
 369        fprintf(stderr, "Finished one %s.\n", me);
 370
 371        /*
 372         *
 373         * If we are cherry-pick, and if the merge did not result in
 374         * hand-editing, we will hit this commit and inherit the original
 375         * author date and name.
 376         * If we are revert, or if our cherry-pick results in a hand merge,
 377         * we had better say that the current user is responsible for that.
 378         */
 379
 380        if (!no_commit) {
 381                if (edit)
 382                        return execl_git_cmd("commit", "-n", NULL);
 383                else
 384                        return execl_git_cmd("commit", "-n", "-F", defmsg, NULL);
 385        }
 386        if (reencoded_message)
 387                free(reencoded_message);
 388
 389        return 0;
 390}
 391
 392int cmd_revert(int argc, const char **argv, const char *prefix)
 393{
 394        if (isatty(0))
 395                edit = 1;
 396        no_replay = 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        no_replay = 0;
 404        action = CHERRY_PICK;
 405        return revert_or_cherry_pick(argc, argv);
 406}