revert: Save data for continuing after conflict resolution
Ever since v1.7.2-rc1~4^2~7 (revert: allow cherry-picking more than one commit, 2010-06-02), a single invocation of "git cherry-pick" or "git revert" can perform picks of several individual commits. To implement features like "--continue" to continue the whole operation, we will need to store some information about the state and the plan at the beginning. Introduce a ".git/sequencer/head" file to store this state, and ".git/sequencer/todo" file to store the plan. The head file contains the SHA-1 of the HEAD before the start of the operation, and the todo file contains an instruction sheet whose format is inspired by the format of the "rebase -i" instruction sheet. As a result, a typical todo file looks like: pick 8537f0e submodule add: test failure when url is not configured pick 4d68932 submodule add: allow relative repository path pick f22a17e submodule add: clean up duplicated code pick 59a5775 make copy_ref globally available Since SHA-1 hex is abbreviated using an find_unique_abbrev(), it is unambiguous. This does not guarantee that there will be no ambiguity when more objects are added to the repository. These two files alone are not enough to implement a "--continue" that remembers the command-line options specified; later patches in the series save them too. These new files are unrelated to the existing .git/CHERRY_PICK_HEAD, which will still be useful while committing after a conflict resolution. Inspired-by: Christian Couder <chriscool@tuxfamily.org> Helped-by: Junio C Hamano <gitster@pobox.com> Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Ramkumar Ramachandra committed
Aug 4, 2011 at 16:09 UTC
04d3d3cfc4a26f003c5ae2b5598cc975a31e4395
2 files changed
+178
-4
builtin/revert.c
+130
-4
@@ -13,6 +13,7 @@
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#include "rerere.h"
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#include "merge-recursive.h"
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#include "refs.h"
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+#include "dir.h"
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/*
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* This implements the builtins revert and cherry-pick.
@@ -60,6 +61,10 @@ struct replay_opts {
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#define GIT_REFLOG_ACTION "GIT_REFLOG_ACTION"
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+#define SEQ_DIR "sequencer"
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+#define SEQ_HEAD_FILE "sequencer/head"
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+#define SEQ_TODO_FILE "sequencer/todo"
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+
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static const char *action_name(const struct replay_opts *opts)
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{
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return opts->action == REVERT ? "revert" : "cherry-pick";
@@ -587,10 +592,116 @@ static void read_and_refresh_cache(struct replay_opts *opts)
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rollback_lock_file(&index_lock);
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}
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-static int pick_commits(struct replay_opts *opts)
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+/*
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+ * Append a commit to the end of the commit_list.
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+ *
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+ * next starts by pointing to the variable that holds the head of an
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+ * empty commit_list, and is updated to point to the "next" field of
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+ * the last item on the list as new commits are appended.
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+ *
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+ * Usage example:
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+ *
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+ * struct commit_list *list;
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+ * struct commit_list **next = &list;
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+ *
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+ * next = commit_list_append(c1, next);
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+ * next = commit_list_append(c2, next);
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+ * assert(commit_list_count(list) == 2);
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+ * return list;
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+ */
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+struct commit_list **commit_list_append(struct commit *commit,
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+ struct commit_list **next)
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+{
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+ struct commit_list *new = xmalloc(sizeof(struct commit_list));
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+ new->item = commit;
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+ *next = new;
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+ new->next = NULL;
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+ return &new->next;
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+}
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+
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+static int format_todo(struct strbuf *buf, struct commit_list *todo_list,
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+ struct replay_opts *opts)
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+{
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+ struct commit_list *cur = NULL;
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+ struct commit_message msg = { NULL, NULL, NULL, NULL, NULL };
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+ const char *sha1_abbrev = NULL;
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+ const char *action_str = opts->action == REVERT ? "revert" : "pick";
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+
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+ for (cur = todo_list; cur; cur = cur->next) {
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+ sha1_abbrev = find_unique_abbrev(cur->item->object.sha1, DEFAULT_ABBREV);
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+ if (get_message(cur->item, &msg))
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+ return error(_("Cannot get commit message for %s"), sha1_abbrev);
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+ strbuf_addf(buf, "%s %s %s\n", action_str, sha1_abbrev, msg.subject);
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+ }
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+ return 0;
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+}
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+
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+static void walk_revs_populate_todo(struct commit_list **todo_list,
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+ struct replay_opts *opts)
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{
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struct rev_info revs;
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struct commit *commit;
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+ struct commit_list **next;
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+
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+ prepare_revs(&revs, opts);
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+
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+ next = todo_list;
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+ while ((commit = get_revision(&revs)))
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+ next = commit_list_append(commit, next);
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+}
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+
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+static void create_seq_dir(void)
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+{
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+ const char *seq_dir = git_path(SEQ_DIR);
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+
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+ if (!(file_exists(seq_dir) && is_directory(seq_dir))
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+ && mkdir(seq_dir, 0777) < 0)
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+ die_errno(_("Could not create sequencer directory '%s'."), seq_dir);
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+}
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+
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+static void save_head(const char *head)
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+{
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+ const char *head_file = git_path(SEQ_HEAD_FILE);
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+ static struct lock_file head_lock;
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+ struct strbuf buf = STRBUF_INIT;
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+ int fd;
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+
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+ fd = hold_lock_file_for_update(&head_lock, head_file, LOCK_DIE_ON_ERROR);
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+ strbuf_addf(&buf, "%s\n", head);
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+ if (write_in_full(fd, buf.buf, buf.len) < 0)
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+ die_errno(_("Could not write to %s."), head_file);
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+ if (commit_lock_file(&head_lock) < 0)
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+ die(_("Error wrapping up %s."), head_file);
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+}
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+
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+static void save_todo(struct commit_list *todo_list, struct replay_opts *opts)
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+{
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+ const char *todo_file = git_path(SEQ_TODO_FILE);
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+ static struct lock_file todo_lock;
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+ struct strbuf buf = STRBUF_INIT;
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+ int fd;
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+
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+ fd = hold_lock_file_for_update(&todo_lock, todo_file, LOCK_DIE_ON_ERROR);
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+ if (format_todo(&buf, todo_list, opts) < 0)
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+ die(_("Could not format %s."), todo_file);
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+ if (write_in_full(fd, buf.buf, buf.len) < 0) {
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+ strbuf_release(&buf);
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+ die_errno(_("Could not write to %s."), todo_file);
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+ }
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+ if (commit_lock_file(&todo_lock) < 0) {
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+ strbuf_release(&buf);
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+ die(_("Error wrapping up %s."), todo_file);
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+ }
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+ strbuf_release(&buf);
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+}
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+
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+static int pick_commits(struct replay_opts *opts)
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+{
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+ struct commit_list *todo_list = NULL;
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+ struct strbuf buf = STRBUF_INIT;
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+ unsigned char sha1[20];
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+ struct commit_list *cur;
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+ int res;
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setenv(GIT_REFLOG_ACTION, action_name(opts), 0);
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if (opts->allow_ff)
@@ -598,14 +709,29 @@ static int pick_commits(struct replay_opts *opts)
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opts->record_origin || opts->edit));
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read_and_refresh_cache(opts);
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- prepare_revs(&revs, opts);
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+ walk_revs_populate_todo(&todo_list, opts);
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+ create_seq_dir();
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+ if (get_sha1("HEAD", sha1)) {
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+ if (opts->action == REVERT)
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+ die(_("Can't revert as initial commit"));
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+ die(_("Can't cherry-pick into empty head"));
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+ }
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+ save_head(sha1_to_hex(sha1));
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- while ((commit = get_revision(&revs))) {
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- int res = do_pick_commit(commit, opts);
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+ for (cur = todo_list; cur; cur = cur->next) {
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+ save_todo(cur, opts);
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+ res = do_pick_commit(cur->item, opts);
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if (res)
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return res;
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}
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+ /*
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+ * Sequence of picks finished successfully; cleanup by
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+ * removing the .git/sequencer directory
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+ */
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+ strbuf_addf(&buf, "%s", git_path(SEQ_DIR));
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+ remove_dir_recursively(&buf, 0);
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+ strbuf_release(&buf);
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return 0;
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}
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t/t3510-cherry-pick-sequence.sh
new
+48
@@ -0,0 +1,48 @@
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+#!/bin/sh
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+
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+test_description='Test cherry-pick continuation features
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+
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+ + anotherpick: rewrites foo to d
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+ + picked: rewrites foo to c
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+ + unrelatedpick: rewrites unrelated to reallyunrelated
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+ + base: rewrites foo to b
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+ + initial: writes foo as a, unrelated as unrelated
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+
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+'
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+
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+. ./test-lib.sh
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+
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+pristine_detach () {
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+ rm -rf .git/sequencer &&
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+ git checkout -f "$1^0" &&
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+ git read-tree -u --reset HEAD &&
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+ git clean -d -f -f -q -x
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+}
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+
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+test_expect_success setup '
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+ echo unrelated >unrelated &&
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+ git add unrelated &&
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+ test_commit initial foo a &&
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+ test_commit base foo b &&
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+ test_commit unrelatedpick unrelated reallyunrelated &&
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+ test_commit picked foo c &&
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+ test_commit anotherpick foo d &&
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+ git config advice.detachedhead false
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+
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+'
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+
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+test_expect_success 'cherry-pick persists data on failure' '
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+ pristine_detach initial &&
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+ test_must_fail git cherry-pick base..anotherpick &&
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+ test_path_is_dir .git/sequencer &&
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+ test_path_is_file .git/sequencer/head &&
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+ test_path_is_file .git/sequencer/todo
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+'
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+
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+test_expect_success 'cherry-pick cleans up sequencer state upon success' '
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+ pristine_detach initial &&
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+ git cherry-pick initial..picked &&
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+ test_path_is_missing .git/sequencer
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+'
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+
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+test_done