diff options
Diffstat (limited to 'builtin/revert.c')
| -rw-r--r-- | builtin/revert.c | 559 |
1 files changed, 559 insertions, 0 deletions
diff --git a/builtin/revert.c b/builtin/revert.c new file mode 100644 index 0000000000..7976b5a329 --- /dev/null +++ b/builtin/revert.c @@ -0,0 +1,559 @@ +#include "cache.h" +#include "builtin.h" +#include "object.h" +#include "commit.h" +#include "tag.h" +#include "wt-status.h" +#include "run-command.h" +#include "exec_cmd.h" +#include "utf8.h" +#include "parse-options.h" +#include "cache-tree.h" +#include "diff.h" +#include "revision.h" +#include "rerere.h" +#include "merge-recursive.h" +#include "refs.h" + +/* + * This implements the builtins revert and cherry-pick. + * + * Copyright (c) 2007 Johannes E. Schindelin + * + * Based on git-revert.sh, which is + * + * Copyright (c) 2005 Linus Torvalds + * Copyright (c) 2005 Junio C Hamano + */ + +static const char * const revert_usage[] = { + "git revert [options] <commit-ish>", + NULL +}; + +static const char * const cherry_pick_usage[] = { + "git cherry-pick [options] <commit-ish>", + NULL +}; + +static int edit, no_replay, no_commit, mainline, signoff, allow_ff; +static enum { REVERT, CHERRY_PICK } action; +static struct commit *commit; +static const char *commit_name; +static int allow_rerere_auto; + +static const char *me; +static const char *strategy; + +#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION" + +static char *get_encoding(const char *message); + +static void parse_args(int argc, const char **argv) +{ + const char * const * usage_str = + action == REVERT ? revert_usage : cherry_pick_usage; + unsigned char sha1[20]; + 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_BOOLEAN('s', "signoff", &signoff, "add Signed-off-by:"), + OPT_INTEGER('m', "mainline", &mainline, "parent number"), + OPT_RERERE_AUTOUPDATE(&allow_rerere_auto), + OPT_STRING(0, "strategy", &strategy, "strategy", "merge strategy"), + OPT_END(), + OPT_END(), + OPT_END(), + }; + + if (action == CHERRY_PICK) { + struct option cp_extra[] = { + OPT_BOOLEAN(0, "ff", &allow_ff, "allow fast-forward"), + OPT_END(), + }; + if (parse_options_concat(options, ARRAY_SIZE(options), cp_extra)) + die("program error"); + } + + if (parse_options(argc, argv, NULL, options, usage_str, 0) != 1) + usage_with_options(usage_str, options); + + commit_name = argv[0]; + if (get_sha1(commit_name, sha1)) + die ("Cannot find '%s'", commit_name); + commit = lookup_commit_reference(sha1); + if (!commit) + exit(1); +} + +struct commit_message { + char *parent_label; + const char *label; + const char *subject; + char *reencoded_message; + const char *message; +}; + +static int get_message(const char *raw_message, struct commit_message *out) +{ + const char *encoding; + const char *p, *abbrev, *eol; + char *q; + int abbrev_len, oneline_len; + + if (!raw_message) + return -1; + encoding = get_encoding(raw_message); + if (!encoding) + encoding = "UTF-8"; + if (!git_commit_encoding) + git_commit_encoding = "UTF-8"; + + out->reencoded_message = NULL; + out->message = raw_message; + if (strcmp(encoding, git_commit_encoding)) + out->reencoded_message = reencode_string(raw_message, + git_commit_encoding, encoding); + if (out->reencoded_message) + out->message = out->reencoded_message; + + abbrev = find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV); + abbrev_len = strlen(abbrev); + + /* Find beginning and end of commit subject. */ + p = out->message; + while (*p && (*p != '\n' || p[1] != '\n')) + p++; + if (*p) { + p += 2; + for (eol = p + 1; *eol && *eol != '\n'; eol++) + ; /* do nothing */ + } else + eol = p; + oneline_len = eol - p; + + out->parent_label = xmalloc(strlen("parent of ") + abbrev_len + + strlen("... ") + oneline_len + 1); + q = out->parent_label; + q = mempcpy(q, "parent of ", strlen("parent of ")); + out->label = q; + q = mempcpy(q, abbrev, abbrev_len); + q = mempcpy(q, "... ", strlen("... ")); + out->subject = q; + q = mempcpy(q, p, oneline_len); + *q = '\0'; + return 0; +} + +static void free_message(struct commit_message *msg) +{ + free(msg->parent_label); + free(msg->reencoded_message); +} + +static char *get_encoding(const char *message) +{ + const char *p = message, *eol; + + if (!p) + die ("Could not read commit message of %s", + sha1_to_hex(commit->object.sha1)); + while (*p && *p != '\n') { + for (eol = p + 1; *eol && *eol != '\n'; eol++) + ; /* do nothing */ + if (!prefixcmp(p, "encoding ")) { + char *result = xmalloc(eol - 8 - p); + strlcpy(result, p + 9, eol - 8 - p); + return result; + } + p = eol; + if (*p == '\n') + p++; + } + return NULL; +} + +static void add_message_to_msg(struct strbuf *msgbuf, const char *message) +{ + const char *p = message; + while (*p && (*p != '\n' || p[1] != '\n')) + p++; + + if (!*p) + strbuf_addstr(msgbuf, sha1_to_hex(commit->object.sha1)); + + p += 2; + strbuf_addstr(msgbuf, p); +} + +static void set_author_ident_env(const char *message) +{ + const char *p = message; + if (!p) + die ("Could not read commit message of %s", + sha1_to_hex(commit->object.sha1)); + while (*p && *p != '\n') { + const char *eol; + + for (eol = p; *eol && *eol != '\n'; eol++) + ; /* do nothing */ + if (!prefixcmp(p, "author ")) { + char *line, *pend, *email, *timestamp; + + p += 7; + line = xmemdupz(p, eol - p); + email = strchr(line, '<'); + if (!email) + die ("Could not extract author email from %s", + sha1_to_hex(commit->object.sha1)); + if (email == line) + pend = line; + else + for (pend = email; pend != line + 1 && + isspace(pend[-1]); pend--); + ; /* do nothing */ + *pend = '\0'; + email++; + timestamp = strchr(email, '>'); + if (!timestamp) + die ("Could not extract author time from %s", + sha1_to_hex(commit->object.sha1)); + *timestamp = '\0'; + for (timestamp++; *timestamp && isspace(*timestamp); + timestamp++) + ; /* do nothing */ + setenv("GIT_AUTHOR_NAME", line, 1); + setenv("GIT_AUTHOR_EMAIL", email, 1); + setenv("GIT_AUTHOR_DATE", timestamp, 1); + free(line); + return; + } + p = eol; + if (*p == '\n') + p++; + } + die ("No author information found in %s", + sha1_to_hex(commit->object.sha1)); +} + +static char *help_msg(const char *name) +{ + struct strbuf helpbuf = STRBUF_INIT; + char *msg = getenv("GIT_CHERRY_PICK_HELP"); + + if (msg) + return msg; + + strbuf_addstr(&helpbuf, " After resolving the conflicts,\n" + "mark the corrected paths with 'git add <paths>' or 'git rm <paths>'\n" + "and commit the result"); + + if (action == CHERRY_PICK) { + strbuf_addf(&helpbuf, " with: \n" + "\n" + " git commit -c %s\n", + name); + } + else + strbuf_addch(&helpbuf, '.'); + return strbuf_detach(&helpbuf, NULL); +} + +static void write_message(struct strbuf *msgbuf, const char *filename) +{ + static struct lock_file msg_file; + + int msg_fd = hold_lock_file_for_update(&msg_file, filename, + LOCK_DIE_ON_ERROR); + if (write_in_full(msg_fd, msgbuf->buf, msgbuf->len) < 0) + die_errno("Could not write to %s.", filename); + strbuf_release(msgbuf); + if (commit_lock_file(&msg_file) < 0) + die("Error wrapping up %s", filename); +} + +static struct tree *empty_tree(void) +{ + struct tree *tree = xcalloc(1, sizeof(struct tree)); + + tree->object.parsed = 1; + tree->object.type = OBJ_TREE; + pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1); + return tree; +} + +static NORETURN void die_dirty_index(const char *me) +{ + if (read_cache_unmerged()) { + die_resolve_conflict(me); + } else { + if (advice_commit_before_merge) + die("Your local changes would be overwritten by %s.\n" + "Please, commit your changes or stash them to proceed.", me); + else + die("Your local changes would be overwritten by %s.\n", me); + } +} + +static int fast_forward_to(const unsigned char *to, const unsigned char *from) +{ + struct ref_lock *ref_lock; + + read_cache(); + if (checkout_fast_forward(from, to)) + exit(1); /* the callee should have complained already */ + ref_lock = lock_any_ref_for_update("HEAD", from, 0); + return write_ref_sha1(ref_lock, to, "cherry-pick"); +} + +static void do_recursive_merge(struct commit *base, struct commit *next, + const char *base_label, const char *next_label, + unsigned char *head, struct strbuf *msgbuf, + char *defmsg) +{ + struct merge_options o; + struct tree *result, *next_tree, *base_tree, *head_tree; + int clean, index_fd; + static struct lock_file index_lock; + + index_fd = hold_locked_index(&index_lock, 1); + + read_cache(); + init_merge_options(&o); + o.ancestor = base ? base_label : "(empty tree)"; + o.branch1 = "HEAD"; + o.branch2 = next ? next_label : "(empty tree)"; + + head_tree = parse_tree_indirect(head); + next_tree = next ? next->tree : empty_tree(); + base_tree = base ? base->tree : empty_tree(); + + clean = merge_trees(&o, + head_tree, + next_tree, base_tree, &result); + + if (active_cache_changed && + (write_cache(index_fd, active_cache, active_nr) || + commit_locked_index(&index_lock))) + die("%s: Unable to write new index file", me); + rollback_lock_file(&index_lock); + + if (!clean) { + int i; + strbuf_addstr(msgbuf, "\nConflicts:\n\n"); + for (i = 0; i < active_nr;) { + struct cache_entry *ce = active_cache[i++]; + if (ce_stage(ce)) { + strbuf_addch(msgbuf, '\t'); + strbuf_addstr(msgbuf, ce->name); + strbuf_addch(msgbuf, '\n'); + while (i < active_nr && !strcmp(ce->name, + active_cache[i]->name)) + i++; + } + } + write_message(msgbuf, defmsg); + fprintf(stderr, "Automatic %s failed.%s\n", + me, help_msg(commit_name)); + rerere(allow_rerere_auto); + exit(1); + } + write_message(msgbuf, defmsg); + fprintf(stderr, "Finished one %s.\n", me); +} + +static int revert_or_cherry_pick(int argc, const char **argv) +{ + unsigned char head[20]; + struct commit *base, *next, *parent; + const char *base_label, *next_label; + struct commit_message msg = { NULL, NULL, NULL, NULL, NULL }; + char *defmsg = NULL; + struct strbuf msgbuf = STRBUF_INIT; + + git_config(git_default_config, NULL); + me = action == REVERT ? "revert" : "cherry-pick"; + setenv(GIT_REFLOG_ACTION, me, 0); + parse_args(argc, argv); + + /* this is copied from the shell script, but it's never triggered... */ + if (action == REVERT && !no_replay) + die("revert is incompatible with replay"); + + if (allow_ff) { + if (signoff) + die("cherry-pick --ff cannot be used with --signoff"); + if (no_commit) + die("cherry-pick --ff cannot be used with --no-commit"); + if (no_replay) + die("cherry-pick --ff cannot be used with -x"); + if (edit) + die("cherry-pick --ff cannot be used with --edit"); + } + + if (read_cache() < 0) + die("git %s: failed to read the index", me); + if (no_commit) { + /* + * We do not intend to commit immediately. We just want to + * merge the differences in, so let's compute the tree + * that represents the "current" state for merge-recursive + * to work on. + */ + if (write_cache_as_tree(head, 0, NULL)) + die ("Your index file is unmerged."); + } else { + if (get_sha1("HEAD", head)) + die ("You do not have a valid HEAD"); + if (index_differs_from("HEAD", 0)) + die_dirty_index(me); + } + discard_cache(); + + if (!commit->parents) { + if (action == REVERT) + die ("Cannot revert a root commit"); + parent = NULL; + } + else 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 (allow_ff && !hashcmp(parent->object.sha1, head)) + return fast_forward_to(commit->object.sha1, head); + + if (parent && parse_commit(parent) < 0) + die("%s: cannot parse parent commit %s", + me, sha1_to_hex(parent->object.sha1)); + + if (get_message(commit->buffer, &msg) != 0) + die("Cannot get commit message for %s", + sha1_to_hex(commit->object.sha1)); + + /* + * "commit" is an existing commit. We would want to apply + * the difference it introduces since its first parent "prev" + * on top of the current HEAD if we are cherry-pick. Or the + * reverse of it if we are revert. + */ + + defmsg = git_pathdup("MERGE_MSG"); + + if (action == REVERT) { + base = commit; + base_label = msg.label; + next = parent; + next_label = msg.parent_label; + strbuf_addstr(&msgbuf, "Revert \""); + strbuf_addstr(&msgbuf, msg.subject); + strbuf_addstr(&msgbuf, "\"\n\nThis reverts commit "); + strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1)); + + if (commit->parents->next) { + strbuf_addstr(&msgbuf, ", reversing\nchanges made to "); + strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1)); + } + strbuf_addstr(&msgbuf, ".\n"); + } else { + base = parent; + base_label = msg.parent_label; + next = commit; + next_label = msg.label; + set_author_ident_env(msg.message); + add_message_to_msg(&msgbuf, msg.message); + if (no_replay) { + strbuf_addstr(&msgbuf, "(cherry picked from commit "); + strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1)); + strbuf_addstr(&msgbuf, ")\n"); + } + } + + if (!strategy || !strcmp(strategy, "recursive") || action == REVERT) + do_recursive_merge(base, next, base_label, next_label, + head, &msgbuf, defmsg); + else { + int res; + struct commit_list *common = NULL; + struct commit_list *remotes = NULL; + write_message(&msgbuf, defmsg); + commit_list_insert(base, &common); + commit_list_insert(next, &remotes); + res = try_merge_command(strategy, common, + sha1_to_hex(head), remotes); + free_commit_list(common); + free_commit_list(remotes); + if (res) { + fprintf(stderr, "Automatic %s with strategy %s failed.%s\n", + me, strategy, help_msg(commit_name)); + rerere(allow_rerere_auto); + exit(1); + } + } + + /* + * + * If we are cherry-pick, and if the merge did not result in + * hand-editing, we will hit this commit and inherit the original + * author date and name. + * If we are revert, or if our cherry-pick results in a hand merge, + * we had better say that the current user is responsible for that. + */ + + if (!no_commit) { + /* 6 is max possible length of our args array including NULL */ + const char *args[6]; + int i = 0; + args[i++] = "commit"; + args[i++] = "-n"; + if (signoff) + args[i++] = "-s"; + if (!edit) { + args[i++] = "-F"; + args[i++] = defmsg; + } + args[i] = NULL; + return execv_git_cmd(args); + } + free_message(&msg); + free(defmsg); + + return 0; +} + +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) +{ + no_replay = 0; + action = CHERRY_PICK; + return revert_or_cherry_pick(argc, argv); +} |