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authorRamkumar Ramachandra <artagnon@gmail.com>2012-01-11 23:45:57 +0530
committerJunio C Hamano <gitster@pobox.com>2012-01-11 18:11:49 -0800
commit043a4492b3b7da6496617201c369cff6ab7c26f2 (patch)
tree3a61dc047a6f3420f9a3878ccc862424403fd344 /sequencer.c
parent644a36908d6b52cb8c0c4d1ac69fd0b451e38f13 (diff)
downloadgit-043a4492b3b7da6496617201c369cff6ab7c26f2.tar.gz
sequencer: factor code out of revert builtinrr/sequencer
Expose the cherry-picking machinery through a public sequencer_pick_revisions() (renamed from pick_revisions() in builtin/revert.c), so that cherry-picking and reverting are special cases of a general sequencer operation. The cherry-pick builtin is now a thin wrapper that does command-line argument parsing before calling into sequencer_pick_revisions(). In the future, we can write a new "foo" builtin that calls into the sequencer like: memset(&opts, 0, sizeof(opts)); opts.action = REPLAY_FOO; opts.revisions = xmalloc(sizeof(*opts.revs)); parse_args_populate_opts(argc, argv, &opts); init_revisions(opts.revs); sequencer_pick_revisions(&opts); This patch does not intend to make any functional changes. Check with: $ git blame -s -C HEAD^..HEAD -- sequencer.c | grep -C3 '^[^^]' Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Reviewed-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'sequencer.c')
-rw-r--r--sequencer.c918
1 files changed, 917 insertions, 1 deletions
diff --git a/sequencer.c b/sequencer.c
index d1f28a6945..54771196c3 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1,7 +1,20 @@
#include "cache.h"
#include "sequencer.h"
-#include "strbuf.h"
#include "dir.h"
+#include "object.h"
+#include "commit.h"
+#include "tag.h"
+#include "run-command.h"
+#include "exec_cmd.h"
+#include "utf8.h"
+#include "cache-tree.h"
+#include "diff.h"
+#include "revision.h"
+#include "rerere.h"
+#include "merge-recursive.h"
+#include "refs.h"
+
+#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
void remove_sequencer_state(void)
{
@@ -11,3 +24,906 @@ void remove_sequencer_state(void)
remove_dir_recursively(&seq_dir, 0);
strbuf_release(&seq_dir);
}
+
+static const char *action_name(const struct replay_opts *opts)
+{
+ return opts->action == REPLAY_REVERT ? "revert" : "cherry-pick";
+}
+
+static char *get_encoding(const char *message);
+
+struct commit_message {
+ char *parent_label;
+ const char *label;
+ const char *subject;
+ char *reencoded_message;
+ const char *message;
+};
+
+static int get_message(struct commit *commit, struct commit_message *out)
+{
+ const char *encoding;
+ const char *abbrev, *subject;
+ int abbrev_len, subject_len;
+ char *q;
+
+ if (!commit->buffer)
+ return -1;
+ encoding = get_encoding(commit->buffer);
+ if (!encoding)
+ encoding = "UTF-8";
+ if (!git_commit_encoding)
+ git_commit_encoding = "UTF-8";
+
+ out->reencoded_message = NULL;
+ out->message = commit->buffer;
+ if (strcmp(encoding, git_commit_encoding))
+ out->reencoded_message = reencode_string(commit->buffer,
+ 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);
+
+ subject_len = find_commit_subject(out->message, &subject);
+
+ out->parent_label = xmalloc(strlen("parent of ") + abbrev_len +
+ strlen("... ") + subject_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, subject, subject_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;
+
+ 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 write_cherry_pick_head(struct commit *commit, const char *pseudoref)
+{
+ const char *filename;
+ int fd;
+ struct strbuf buf = STRBUF_INIT;
+
+ strbuf_addf(&buf, "%s\n", sha1_to_hex(commit->object.sha1));
+
+ filename = git_path("%s", pseudoref);
+ fd = open(filename, O_WRONLY | O_CREAT, 0666);
+ if (fd < 0)
+ die_errno(_("Could not open '%s' for writing"), filename);
+ if (write_in_full(fd, buf.buf, buf.len) != buf.len || close(fd))
+ die_errno(_("Could not write to '%s'"), filename);
+ strbuf_release(&buf);
+}
+
+static void print_advice(int show_hint)
+{
+ char *msg = getenv("GIT_CHERRY_PICK_HELP");
+
+ if (msg) {
+ fprintf(stderr, "%s\n", msg);
+ /*
+ * A conflict has occured but the porcelain
+ * (typically rebase --interactive) wants to take care
+ * of the commit itself so remove CHERRY_PICK_HEAD
+ */
+ unlink(git_path("CHERRY_PICK_HEAD"));
+ return;
+ }
+
+ if (show_hint) {
+ advise("after resolving the conflicts, mark the corrected paths");
+ advise("with 'git add <paths>' or 'git rm <paths>'");
+ advise("and commit the result with 'git commit'");
+ }
+}
+
+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)
+{
+ return lookup_tree((const unsigned char *)EMPTY_TREE_SHA1_BIN);
+}
+
+static int error_dirty_index(struct replay_opts *opts)
+{
+ if (read_cache_unmerged())
+ return error_resolve_conflict(action_name(opts));
+
+ /* Different translation strings for cherry-pick and revert */
+ if (opts->action == REPLAY_PICK)
+ error(_("Your local changes would be overwritten by cherry-pick."));
+ else
+ error(_("Your local changes would be overwritten by revert."));
+
+ if (advice_commit_before_merge)
+ advise(_("Commit your changes or stash them to proceed."));
+ return -1;
+}
+
+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 int do_recursive_merge(struct commit *base, struct commit *next,
+ const char *base_label, const char *next_label,
+ unsigned char *head, struct strbuf *msgbuf,
+ struct replay_opts *opts)
+{
+ struct merge_options o;
+ struct tree *result, *next_tree, *base_tree, *head_tree;
+ int clean, index_fd;
+ const char **xopt;
+ 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();
+
+ for (xopt = opts->xopts; xopt != opts->xopts + opts->xopts_nr; xopt++)
+ parse_merge_opt(&o, *xopt);
+
+ 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)))
+ /* TRANSLATORS: %s will be "revert" or "cherry-pick" */
+ die(_("%s: Unable to write new index file"), action_name(opts));
+ 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++;
+ }
+ }
+ }
+
+ return !clean;
+}
+
+/*
+ * 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.
+ */
+static int run_git_commit(const char *defmsg, struct replay_opts *opts)
+{
+ /* 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 (opts->signoff)
+ args[i++] = "-s";
+ if (!opts->edit) {
+ args[i++] = "-F";
+ args[i++] = defmsg;
+ }
+ args[i] = NULL;
+
+ return run_command_v_opt(args, RUN_GIT_CMD);
+}
+
+static int do_pick_commit(struct commit *commit, struct replay_opts *opts)
+{
+ 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;
+ int res;
+
+ if (opts->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))
+ return error(_("You do not have a valid HEAD"));
+ if (index_differs_from("HEAD", 0))
+ return error_dirty_index(opts);
+ }
+ discard_cache();
+
+ if (!commit->parents) {
+ parent = NULL;
+ }
+ else if (commit->parents->next) {
+ /* Reverting or cherry-picking a merge commit */
+ int cnt;
+ struct commit_list *p;
+
+ if (!opts->mainline)
+ return error(_("Commit %s is a merge but no -m option was given."),
+ sha1_to_hex(commit->object.sha1));
+
+ for (cnt = 1, p = commit->parents;
+ cnt != opts->mainline && p;
+ cnt++)
+ p = p->next;
+ if (cnt != opts->mainline || !p)
+ return error(_("Commit %s does not have parent %d"),
+ sha1_to_hex(commit->object.sha1), opts->mainline);
+ parent = p->item;
+ } else if (0 < opts->mainline)
+ return error(_("Mainline was specified but commit %s is not a merge."),
+ sha1_to_hex(commit->object.sha1));
+ else
+ parent = commit->parents->item;
+
+ if (opts->allow_ff && parent && !hashcmp(parent->object.sha1, head))
+ return fast_forward_to(commit->object.sha1, head);
+
+ if (parent && parse_commit(parent) < 0)
+ /* TRANSLATORS: The first %s will be "revert" or
+ "cherry-pick", the second %s a SHA1 */
+ return error(_("%s: cannot parse parent commit %s"),
+ action_name(opts), sha1_to_hex(parent->object.sha1));
+
+ if (get_message(commit, &msg) != 0)
+ return error(_("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 (opts->action == REPLAY_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 && commit->parents->next) {
+ strbuf_addstr(&msgbuf, ", reversing\nchanges made to ");
+ strbuf_addstr(&msgbuf, sha1_to_hex(parent->object.sha1));
+ }
+ strbuf_addstr(&msgbuf, ".\n");
+ } else {
+ const char *p;
+
+ base = parent;
+ base_label = msg.parent_label;
+ next = commit;
+ next_label = msg.label;
+
+ /*
+ * Append the commit log message to msgbuf; it starts
+ * after the tree, parent, author, committer
+ * information followed by "\n\n".
+ */
+ p = strstr(msg.message, "\n\n");
+ if (p) {
+ p += 2;
+ strbuf_addstr(&msgbuf, p);
+ }
+
+ if (opts->record_origin) {
+ strbuf_addstr(&msgbuf, "(cherry picked from commit ");
+ strbuf_addstr(&msgbuf, sha1_to_hex(commit->object.sha1));
+ strbuf_addstr(&msgbuf, ")\n");
+ }
+ }
+
+ if (!opts->strategy || !strcmp(opts->strategy, "recursive") || opts->action == REPLAY_REVERT) {
+ res = do_recursive_merge(base, next, base_label, next_label,
+ head, &msgbuf, opts);
+ write_message(&msgbuf, defmsg);
+ } else {
+ 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(opts->strategy, opts->xopts_nr, opts->xopts,
+ common, sha1_to_hex(head), remotes);
+ free_commit_list(common);
+ free_commit_list(remotes);
+ }
+
+ /*
+ * If the merge was clean or if it failed due to conflict, we write
+ * CHERRY_PICK_HEAD for the subsequent invocation of commit to use.
+ * However, if the merge did not even start, then we don't want to
+ * write it at all.
+ */
+ if (opts->action == REPLAY_PICK && !opts->no_commit && (res == 0 || res == 1))
+ write_cherry_pick_head(commit, "CHERRY_PICK_HEAD");
+ if (opts->action == REPLAY_REVERT && ((opts->no_commit && res == 0) || res == 1))
+ write_cherry_pick_head(commit, "REVERT_HEAD");
+
+ if (res) {
+ error(opts->action == REPLAY_REVERT
+ ? _("could not revert %s... %s")
+ : _("could not apply %s... %s"),
+ find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV),
+ msg.subject);
+ print_advice(res == 1);
+ rerere(opts->allow_rerere_auto);
+ } else {
+ if (!opts->no_commit)
+ res = run_git_commit(defmsg, opts);
+ }
+
+ free_message(&msg);
+ free(defmsg);
+
+ return res;
+}
+
+static void prepare_revs(struct replay_opts *opts)
+{
+ if (opts->action != REPLAY_REVERT)
+ opts->revs->reverse ^= 1;
+
+ if (prepare_revision_walk(opts->revs))
+ die(_("revision walk setup failed"));
+
+ if (!opts->revs->commits)
+ die(_("empty commit set passed"));
+}
+
+static void read_and_refresh_cache(struct replay_opts *opts)
+{
+ static struct lock_file index_lock;
+ int index_fd = hold_locked_index(&index_lock, 0);
+ if (read_index_preload(&the_index, NULL) < 0)
+ die(_("git %s: failed to read the index"), action_name(opts));
+ refresh_index(&the_index, REFRESH_QUIET|REFRESH_UNMERGED, NULL, NULL, NULL);
+ if (the_index.cache_changed) {
+ if (write_index(&the_index, index_fd) ||
+ commit_locked_index(&index_lock))
+ die(_("git %s: failed to refresh the index"), action_name(opts));
+ }
+ rollback_lock_file(&index_lock);
+}
+
+/*
+ * Append a commit to the end of the commit_list.
+ *
+ * next starts by pointing to the variable that holds the head of an
+ * empty commit_list, and is updated to point to the "next" field of
+ * the last item on the list as new commits are appended.
+ *
+ * Usage example:
+ *
+ * struct commit_list *list;
+ * struct commit_list **next = &list;
+ *
+ * next = commit_list_append(c1, next);
+ * next = commit_list_append(c2, next);
+ * assert(commit_list_count(list) == 2);
+ * return list;
+ */
+static struct commit_list **commit_list_append(struct commit *commit,
+ struct commit_list **next)
+{
+ struct commit_list *new = xmalloc(sizeof(struct commit_list));
+ new->item = commit;
+ *next = new;
+ new->next = NULL;
+ return &new->next;
+}
+
+static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
+ struct replay_opts *opts)
+{
+ struct commit_list *cur = NULL;
+ const char *sha1_abbrev = NULL;
+ const char *action_str = opts->action == REPLAY_REVERT ? "revert" : "pick";
+ const char *subject;
+ int subject_len;
+
+ for (cur = todo_list; cur; cur = cur->next) {
+ sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
+ subject_len = find_commit_subject(cur->item->buffer, &subject);
+ strbuf_addf(buf, "%s %s %.*s\n", action_str, sha1_abbrev,
+ subject_len, subject);
+ }
+ return 0;
+}
+
+static struct commit *parse_insn_line(char *bol, char *eol, struct replay_opts *opts)
+{
+ unsigned char commit_sha1[20];
+ enum replay_action action;
+ char *end_of_object_name;
+ int saved, status, padding;
+
+ if (!prefixcmp(bol, "pick")) {
+ action = REPLAY_PICK;
+ bol += strlen("pick");
+ } else if (!prefixcmp(bol, "revert")) {
+ action = REPLAY_REVERT;
+ bol += strlen("revert");
+ } else
+ return NULL;
+
+ /* Eat up extra spaces/ tabs before object name */
+ padding = strspn(bol, " \t");
+ if (!padding)
+ return NULL;
+ bol += padding;
+
+ end_of_object_name = bol + strcspn(bol, " \t\n");
+ saved = *end_of_object_name;
+ *end_of_object_name = '\0';
+ status = get_sha1(bol, commit_sha1);
+ *end_of_object_name = saved;
+
+ /*
+ * Verify that the action matches up with the one in
+ * opts; we don't support arbitrary instructions
+ */
+ if (action != opts->action) {
+ const char *action_str;
+ action_str = action == REPLAY_REVERT ? "revert" : "cherry-pick";
+ error(_("Cannot %s during a %s"), action_str, action_name(opts));
+ return NULL;
+ }
+
+ if (status < 0)
+ return NULL;
+
+ return lookup_commit_reference(commit_sha1);
+}
+
+static int parse_insn_buffer(char *buf, struct commit_list **todo_list,
+ struct replay_opts *opts)
+{
+ struct commit_list **next = todo_list;
+ struct commit *commit;
+ char *p = buf;
+ int i;
+
+ for (i = 1; *p; i++) {
+ char *eol = strchrnul(p, '\n');
+ commit = parse_insn_line(p, eol, opts);
+ if (!commit)
+ return error(_("Could not parse line %d."), i);
+ next = commit_list_append(commit, next);
+ p = *eol ? eol + 1 : eol;
+ }
+ if (!*todo_list)
+ return error(_("No commits parsed."));
+ return 0;
+}
+
+static void read_populate_todo(struct commit_list **todo_list,
+ struct replay_opts *opts)
+{
+ const char *todo_file = git_path(SEQ_TODO_FILE);
+ struct strbuf buf = STRBUF_INIT;
+ int fd, res;
+
+ fd = open(todo_file, O_RDONLY);
+ if (fd < 0)
+ die_errno(_("Could not open %s"), todo_file);
+ if (strbuf_read(&buf, fd, 0) < 0) {
+ close(fd);
+ strbuf_release(&buf);
+ die(_("Could not read %s."), todo_file);
+ }
+ close(fd);
+
+ res = parse_insn_buffer(buf.buf, todo_list, opts);
+ strbuf_release(&buf);
+ if (res)
+ die(_("Unusable instruction sheet: %s"), todo_file);
+}
+
+static int populate_opts_cb(const char *key, const char *value, void *data)
+{
+ struct replay_opts *opts = data;
+ int error_flag = 1;
+
+ if (!value)
+ error_flag = 0;
+ else if (!strcmp(key, "options.no-commit"))
+ opts->no_commit = git_config_bool_or_int(key, value, &error_flag);
+ else if (!strcmp(key, "options.edit"))
+ opts->edit = git_config_bool_or_int(key, value, &error_flag);
+ else if (!strcmp(key, "options.signoff"))
+ opts->signoff = git_config_bool_or_int(key, value, &error_flag);
+ else if (!strcmp(key, "options.record-origin"))
+ opts->record_origin = git_config_bool_or_int(key, value, &error_flag);
+ else if (!strcmp(key, "options.allow-ff"))
+ opts->allow_ff = git_config_bool_or_int(key, value, &error_flag);
+ else if (!strcmp(key, "options.mainline"))
+ opts->mainline = git_config_int(key, value);
+ else if (!strcmp(key, "options.strategy"))
+ git_config_string(&opts->strategy, key, value);
+ else if (!strcmp(key, "options.strategy-option")) {
+ ALLOC_GROW(opts->xopts, opts->xopts_nr + 1, opts->xopts_alloc);
+ opts->xopts[opts->xopts_nr++] = xstrdup(value);
+ } else
+ return error(_("Invalid key: %s"), key);
+
+ if (!error_flag)
+ return error(_("Invalid value for %s: %s"), key, value);
+
+ return 0;
+}
+
+static void read_populate_opts(struct replay_opts **opts_ptr)
+{
+ const char *opts_file = git_path(SEQ_OPTS_FILE);
+
+ if (!file_exists(opts_file))
+ return;
+ if (git_config_from_file(populate_opts_cb, opts_file, *opts_ptr) < 0)
+ die(_("Malformed options sheet: %s"), opts_file);
+}
+
+static void walk_revs_populate_todo(struct commit_list **todo_list,
+ struct replay_opts *opts)
+{
+ struct commit *commit;
+ struct commit_list **next;
+
+ prepare_revs(opts);
+
+ next = todo_list;
+ while ((commit = get_revision(opts->revs)))
+ next = commit_list_append(commit, next);
+}
+
+static int create_seq_dir(void)
+{
+ const char *seq_dir = git_path(SEQ_DIR);
+
+ if (file_exists(seq_dir)) {
+ error(_("a cherry-pick or revert is already in progress"));
+ advise(_("try \"git cherry-pick (--continue | --quit | --abort)\""));
+ return -1;
+ }
+ else if (mkdir(seq_dir, 0777) < 0)
+ die_errno(_("Could not create sequencer directory %s"), seq_dir);
+ return 0;
+}
+
+static void save_head(const char *head)
+{
+ const char *head_file = git_path(SEQ_HEAD_FILE);
+ static struct lock_file head_lock;
+ struct strbuf buf = STRBUF_INIT;
+ int fd;
+
+ fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
+ strbuf_addf(&buf, "%s\n", head);
+ if (write_in_full(fd, buf.buf, buf.len) < 0)
+ die_errno(_("Could not write to %s"), head_file);
+ if (commit_lock_file(&head_lock) < 0)
+ die(_("Error wrapping up %s."), head_file);
+}
+
+static int reset_for_rollback(const unsigned char *sha1)
+{
+ const char *argv[4]; /* reset --merge <arg> + NULL */
+ argv[0] = "reset";
+ argv[1] = "--merge";
+ argv[2] = sha1_to_hex(sha1);
+ argv[3] = NULL;
+ return run_command_v_opt(argv, RUN_GIT_CMD);
+}
+
+static int rollback_single_pick(void)
+{
+ unsigned char head_sha1[20];
+
+ if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
+ !file_exists(git_path("REVERT_HEAD")))
+ return error(_("no cherry-pick or revert in progress"));
+ if (read_ref_full("HEAD", head_sha1, 0, NULL))
+ return error(_("cannot resolve HEAD"));
+ if (is_null_sha1(head_sha1))
+ return error(_("cannot abort from a branch yet to be born"));
+ return reset_for_rollback(head_sha1);
+}
+
+static int sequencer_rollback(struct replay_opts *opts)
+{
+ const char *filename;
+ FILE *f;
+ unsigned char sha1[20];
+ struct strbuf buf = STRBUF_INIT;
+
+ filename = git_path(SEQ_HEAD_FILE);
+ f = fopen(filename, "r");
+ if (!f && errno == ENOENT) {
+ /*
+ * There is no multiple-cherry-pick in progress.
+ * If CHERRY_PICK_HEAD or REVERT_HEAD indicates
+ * a single-cherry-pick in progress, abort that.
+ */
+ return rollback_single_pick();
+ }
+ if (!f)
+ return error(_("cannot open %s: %s"), filename,
+ strerror(errno));
+ if (strbuf_getline(&buf, f, '\n')) {
+ error(_("cannot read %s: %s"), filename, ferror(f) ?
+ strerror(errno) : _("unexpected end of file"));
+ fclose(f);
+ goto fail;
+ }
+ fclose(f);
+ if (get_sha1_hex(buf.buf, sha1) || buf.buf[40] != '\0') {
+ error(_("stored pre-cherry-pick HEAD file '%s' is corrupt"),
+ filename);
+ goto fail;
+ }
+ if (reset_for_rollback(sha1))
+ goto fail;
+ remove_sequencer_state();
+ strbuf_release(&buf);
+ return 0;
+fail:
+ strbuf_release(&buf);
+ return -1;
+}
+
+static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
+{
+ const char *todo_file = git_path(SEQ_TODO_FILE);
+ static struct lock_file todo_lock;
+ struct strbuf buf = STRBUF_INIT;
+ int fd;
+
+ fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
+ if (format_todo(&buf, todo_list, opts) < 0)
+ die(_("Could not format %s."), todo_file);
+ if (write_in_full(fd, buf.buf, buf.len) < 0) {
+ strbuf_release(&buf);
+ die_errno(_("Could not write to %s"), todo_file);
+ }
+ if (commit_lock_file(&todo_lock) < 0) {
+ strbuf_release(&buf);
+ die(_("Error wrapping up %s."), todo_file);
+ }
+ strbuf_release(&buf);
+}
+
+static void save_opts(struct replay_opts *opts)
+{
+ const char *opts_file = git_path(SEQ_OPTS_FILE);
+
+ if (opts->no_commit)
+ git_config_set_in_file(opts_file, "options.no-commit", "true");
+ if (opts->edit)
+ git_config_set_in_file(opts_file, "options.edit", "true");
+ if (opts->signoff)
+ git_config_set_in_file(opts_file, "options.signoff", "true");
+ if (opts->record_origin)
+ git_config_set_in_file(opts_file, "options.record-origin", "true");
+ if (opts->allow_ff)
+ git_config_set_in_file(opts_file, "options.allow-ff", "true");
+ if (opts->mainline) {
+ struct strbuf buf = STRBUF_INIT;
+ strbuf_addf(&buf, "%d", opts->mainline);
+ git_config_set_in_file(opts_file, "options.mainline", buf.buf);
+ strbuf_release(&buf);
+ }
+ if (opts->strategy)
+ git_config_set_in_file(opts_file, "options.strategy", opts->strategy);
+ if (opts->xopts) {
+ int i;
+ for (i = 0; i < opts->xopts_nr; i++)
+ git_config_set_multivar_in_file(opts_file,
+ "options.strategy-option",
+ opts->xopts[i], "^$", 0);
+ }
+}
+
+static int pick_commits(struct commit_list *todo_list, struct replay_opts *opts)
+{
+ struct commit_list *cur;
+ int res;
+
+ setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
+ if (opts->allow_ff)
+ assert(!(opts->signoff || opts->no_commit ||
+ opts->record_origin || opts->edit));
+ read_and_refresh_cache(opts);
+
+ for (cur = todo_list; cur; cur = cur->next) {
+ save_todo(cur, opts);
+ res = do_pick_commit(cur->item, opts);
+ if (res)
+ return res;
+ }
+
+ /*
+ * Sequence of picks finished successfully; cleanup by
+ * removing the .git/sequencer directory
+ */
+ remove_sequencer_state();
+ return 0;
+}
+
+static int continue_single_pick(void)
+{
+ const char *argv[] = { "commit", NULL };
+
+ if (!file_exists(git_path("CHERRY_PICK_HEAD")) &&
+ !file_exists(git_path("REVERT_HEAD")))
+ return error(_("no cherry-pick or revert in progress"));
+ return run_command_v_opt(argv, RUN_GIT_CMD);
+}
+
+static int sequencer_continue(struct replay_opts *opts)
+{
+ struct commit_list *todo_list = NULL;
+
+ if (!file_exists(git_path(SEQ_TODO_FILE)))
+ return continue_single_pick();
+ read_populate_opts(&opts);
+ read_populate_todo(&todo_list, opts);
+
+ /* Verify that the conflict has been resolved */
+ if (file_exists(git_path("CHERRY_PICK_HEAD")) ||
+ file_exists(git_path("REVERT_HEAD"))) {
+ int ret = continue_single_pick();
+ if (ret)
+ return ret;
+ }
+ if (index_differs_from("HEAD", 0))
+ return error_dirty_index(opts);
+ todo_list = todo_list->next;
+ return pick_commits(todo_list, opts);
+}
+
+static int single_pick(struct commit *cmit, struct replay_opts *opts)
+{
+ setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
+ return do_pick_commit(cmit, opts);
+}
+
+int sequencer_pick_revisions(struct replay_opts *opts)
+{
+ struct commit_list *todo_list = NULL;
+ unsigned char sha1[20];
+
+ if (opts->subcommand == REPLAY_NONE)
+ assert(opts->revs);
+
+ read_and_refresh_cache(opts);
+
+ /*
+ * Decide what to do depending on the arguments; a fresh
+ * cherry-pick should be handled differently from an existing
+ * one that is being continued
+ */
+ if (opts->subcommand == REPLAY_REMOVE_STATE) {
+ remove_sequencer_state();
+ return 0;
+ }
+ if (opts->subcommand == REPLAY_ROLLBACK)
+ return sequencer_rollback(opts);
+ if (opts->subcommand == REPLAY_CONTINUE)
+ return sequencer_continue(opts);
+
+ /*
+ * If we were called as "git cherry-pick <commit>", just
+ * cherry-pick/revert it, set CHERRY_PICK_HEAD /
+ * REVERT_HEAD, and don't touch the sequencer state.
+ * This means it is possible to cherry-pick in the middle
+ * of a cherry-pick sequence.
+ */
+ if (opts->revs->cmdline.nr == 1 &&
+ opts->revs->cmdline.rev->whence == REV_CMD_REV &&
+ opts->revs->no_walk &&
+ !opts->revs->cmdline.rev->flags) {
+ struct commit *cmit;
+ if (prepare_revision_walk(opts->revs))
+ die(_("revision walk setup failed"));
+ cmit = get_revision(opts->revs);
+ if (!cmit || get_revision(opts->revs))
+ die("BUG: expected exactly one commit from walk");
+ return single_pick(cmit, opts);
+ }
+
+ /*
+ * Start a new cherry-pick/ revert sequence; but
+ * first, make sure that an existing one isn't in
+ * progress
+ */
+
+ walk_revs_populate_todo(&todo_list, opts);
+ if (create_seq_dir() < 0)
+ return -1;
+ if (get_sha1("HEAD", sha1)) {
+ if (opts->action == REPLAY_REVERT)
+ return error(_("Can't revert as initial commit"));
+ return error(_("Can't cherry-pick into empty head"));
+ }
+ save_head(sha1_to_hex(sha1));
+ save_opts(opts);
+ return pick_commits(todo_list, opts);
+}