rebase.c 33.1 KB
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/*
 * Copyright (C) the libgit2 contributors. All rights reserved.
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */

#include "common.h"
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#include "buffer.h"
#include "repository.h"
#include "posix.h"
#include "filebuf.h"
#include "merge.h"
#include "array.h"
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#include "config.h"
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#include "annotated_commit.h"
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#include "index.h"
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#include <git2/types.h>
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#include <git2/annotated_commit.h>
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#include <git2/rebase.h>
#include <git2/commit.h>
#include <git2/reset.h>
#include <git2/revwalk.h>
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#include <git2/notes.h>
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#define REBASE_APPLY_DIR    "rebase-apply"
#define REBASE_MERGE_DIR    "rebase-merge"
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#define HEAD_NAME_FILE      "head-name"
#define ORIG_HEAD_FILE      "orig-head"
#define HEAD_FILE           "head"
#define ONTO_FILE           "onto"
#define ONTO_NAME_FILE      "onto_name"
#define QUIET_FILE          "quiet"
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#define MSGNUM_FILE         "msgnum"
#define END_FILE            "end"
#define CMT_FILE_FMT        "cmt.%" PRIuZ
#define CURRENT_FILE        "current"
#define REWRITTEN_FILE      "rewritten"
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#define ORIG_DETACHED_HEAD  "detached HEAD"
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#define NOTES_DEFAULT_REF   NULL
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#define REBASE_DIR_MODE     0777
#define REBASE_FILE_MODE    0666
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typedef enum {
	GIT_REBASE_TYPE_NONE = 0,
	GIT_REBASE_TYPE_APPLY = 1,
	GIT_REBASE_TYPE_MERGE = 2,
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	GIT_REBASE_TYPE_INTERACTIVE = 3,
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} git_rebase_type_t;

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struct git_rebase {
	git_repository *repo;

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	git_rebase_options options;

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	git_rebase_type_t type;
	char *state_path;

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	int head_detached : 1,
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		inmemory : 1,
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		quiet : 1,
		started : 1;
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	git_array_t(git_rebase_operation) operations;
	size_t current;

	/* Used by in-memory rebase */
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	git_index *index;
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	git_commit *last_commit;

	/* Used by regular (not in-memory) merge-style rebase */
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	git_oid orig_head_id;
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	char *orig_head_name;
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	git_oid onto_id;
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	char *onto_name;
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};
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#define GIT_REBASE_STATE_INIT {0}

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static int rebase_state_type(
	git_rebase_type_t *type_out,
	char **path_out,
	git_repository *repo)
{
	git_buf path = GIT_BUF_INIT;
	git_rebase_type_t type = GIT_REBASE_TYPE_NONE;

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	if (git_buf_joinpath(&path, repo->gitdir, REBASE_APPLY_DIR) < 0)
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		return -1;

	if (git_path_isdir(git_buf_cstr(&path))) {
		type = GIT_REBASE_TYPE_APPLY;
		goto done;
	}

	git_buf_clear(&path);
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	if (git_buf_joinpath(&path, repo->gitdir, REBASE_MERGE_DIR) < 0)
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		return -1;

	if (git_path_isdir(git_buf_cstr(&path))) {
		type = GIT_REBASE_TYPE_MERGE;
		goto done;
	}

done:
	*type_out = type;

	if (type != GIT_REBASE_TYPE_NONE && path_out)
		*path_out = git_buf_detach(&path);

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	git_buf_dispose(&path);
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	return 0;
}

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GIT_INLINE(int) rebase_readfile(
	git_buf *out,
	git_buf *state_path,
	const char *filename)
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{
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	size_t state_path_len = state_path->size;
	int error;
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	git_buf_clear(out);

	if ((error = git_buf_joinpath(state_path, state_path->ptr, filename)) < 0 ||
		(error = git_futils_readbuffer(out, state_path->ptr)) < 0)
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		goto done;

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	git_buf_rtrim(out);
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done:
	git_buf_truncate(state_path, state_path_len);
	return error;
}
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GIT_INLINE(int) rebase_readint(
	size_t *out, git_buf *asc_out, git_buf *state_path, const char *filename)
{
	int32_t num;
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	const char *eol;
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	int error = 0;
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	if ((error = rebase_readfile(asc_out, state_path, filename)) < 0)
		return error;
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	if (git__strtol32(&num, asc_out->ptr, &eol, 10) < 0 || num < 0 || *eol) {
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		giterr_set(GITERR_REBASE, "the file '%s' contains an invalid numeric value", filename);
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		return -1;
	}
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	*out = (size_t) num;
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	return 0;
}
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GIT_INLINE(int) rebase_readoid(
	git_oid *out, git_buf *str_out, git_buf *state_path, const char *filename)
{
	int error;
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	if ((error = rebase_readfile(str_out, state_path, filename)) < 0)
		return error;
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	if (str_out->size != GIT_OID_HEXSZ || git_oid_fromstr(out, str_out->ptr) < 0) {
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		giterr_set(GITERR_REBASE, "the file '%s' contains an invalid object ID", filename);
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		return -1;
	}
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	return 0;
}
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static git_rebase_operation *rebase_operation_alloc(
	git_rebase *rebase,
	git_rebase_operation_t type,
	git_oid *id,
	const char *exec)
{
	git_rebase_operation *operation;

	assert((type == GIT_REBASE_OPERATION_EXEC) == !id);
	assert((type == GIT_REBASE_OPERATION_EXEC) == !!exec);

	if ((operation = git_array_alloc(rebase->operations)) == NULL)
		return NULL;

	operation->type = type;
	git_oid_cpy((git_oid *)&operation->id, id);
	operation->exec = exec;

	return operation;
}

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static int rebase_open_merge(git_rebase *rebase)
{
	git_buf state_path = GIT_BUF_INIT, buf = GIT_BUF_INIT, cmt = GIT_BUF_INIT;
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	git_oid id;
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	git_rebase_operation *operation;
	size_t i, msgnum = 0, end;
	int error;
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	if ((error = git_buf_puts(&state_path, rebase->state_path)) < 0)
		goto done;
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	/* Read 'msgnum' if it exists (otherwise, let msgnum = 0) */
	if ((error = rebase_readint(&msgnum, &buf, &state_path, MSGNUM_FILE)) < 0 &&
		error != GIT_ENOTFOUND)
		goto done;
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	if (msgnum) {
		rebase->started = 1;
		rebase->current = msgnum - 1;
	}
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	/* Read 'end' */
	if ((error = rebase_readint(&end, &buf, &state_path, END_FILE)) < 0)
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		goto done;

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	/* Read 'current' if it exists */
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	if ((error = rebase_readoid(&id, &buf, &state_path, CURRENT_FILE)) < 0 &&
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		error != GIT_ENOTFOUND)
		goto done;

	/* Read cmt.* */
	git_array_init_to_size(rebase->operations, end);
	GITERR_CHECK_ARRAY(rebase->operations);
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	for (i = 0; i < end; i++) {
		git_buf_clear(&cmt);

		if ((error = git_buf_printf(&cmt, "cmt.%" PRIuZ, (i+1))) < 0 ||
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			(error = rebase_readoid(&id, &buf, &state_path, cmt.ptr)) < 0)
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			goto done;
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		operation = rebase_operation_alloc(rebase, GIT_REBASE_OPERATION_PICK, &id, NULL);
		GITERR_CHECK_ALLOC(operation);
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	}
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	/* Read 'onto_name' */
	if ((error = rebase_readfile(&buf, &state_path, ONTO_NAME_FILE)) < 0)
		goto done;

	rebase->onto_name = git_buf_detach(&buf);

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done:
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	git_buf_dispose(&cmt);
	git_buf_dispose(&state_path);
	git_buf_dispose(&buf);
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	return error;
}

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static int rebase_alloc(git_rebase **out, const git_rebase_options *rebase_opts)
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{
	git_rebase *rebase = git__calloc(1, sizeof(git_rebase));
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	GITERR_CHECK_ALLOC(rebase);
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	*out = NULL;
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	if (rebase_opts)
		memcpy(&rebase->options, rebase_opts, sizeof(git_rebase_options));
	else
		git_rebase_init_options(&rebase->options, GIT_REBASE_OPTIONS_VERSION);

	if (rebase_opts && rebase_opts->rewrite_notes_ref) {
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		rebase->options.rewrite_notes_ref = git__strdup(rebase_opts->rewrite_notes_ref);
		GITERR_CHECK_ALLOC(rebase->options.rewrite_notes_ref);
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	}

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	*out = rebase;

	return 0;
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}

static int rebase_check_versions(const git_rebase_options *given_opts)
{
	GITERR_CHECK_VERSION(given_opts, GIT_REBASE_OPTIONS_VERSION, "git_rebase_options");

	if (given_opts)
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		GITERR_CHECK_VERSION(&given_opts->checkout_options, GIT_CHECKOUT_OPTIONS_VERSION, "git_checkout_options");
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	return 0;
}

int git_rebase_open(
	git_rebase **out,
	git_repository *repo,
	const git_rebase_options *given_opts)
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{
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	git_rebase *rebase;
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	git_buf path = GIT_BUF_INIT, orig_head_name = GIT_BUF_INIT,
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		orig_head_id = GIT_BUF_INIT, onto_id = GIT_BUF_INIT;
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	int state_path_len, error;

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	assert(repo);

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	if ((error = rebase_check_versions(given_opts)) < 0)
		return error;

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	if (rebase_alloc(&rebase, given_opts) < 0)
		return -1;
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	rebase->repo = repo;

	if ((error = rebase_state_type(&rebase->type, &rebase->state_path, repo)) < 0)
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		goto done;

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	if (rebase->type == GIT_REBASE_TYPE_NONE) {
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		giterr_set(GITERR_REBASE, "there is no rebase in progress");
Jacques Germishuys committed
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		error = GIT_ENOTFOUND;
		goto done;
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	}

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	if ((error = git_buf_puts(&path, rebase->state_path)) < 0)
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		goto done;

	state_path_len = git_buf_len(&path);

	if ((error = git_buf_joinpath(&path, path.ptr, HEAD_NAME_FILE)) < 0 ||
		(error = git_futils_readbuffer(&orig_head_name, path.ptr)) < 0)
		goto done;

	git_buf_rtrim(&orig_head_name);

	if (strcmp(ORIG_DETACHED_HEAD, orig_head_name.ptr) == 0)
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		rebase->head_detached = 1;
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	git_buf_truncate(&path, state_path_len);

	if ((error = git_buf_joinpath(&path, path.ptr, ORIG_HEAD_FILE)) < 0)
		goto done;

	if (!git_path_isfile(path.ptr)) {
		/* Previous versions of git.git used 'head' here; support that. */
		git_buf_truncate(&path, state_path_len);

		if ((error = git_buf_joinpath(&path, path.ptr, HEAD_FILE)) < 0)
			goto done;
	}

	if ((error = git_futils_readbuffer(&orig_head_id, path.ptr)) < 0)
		goto done;

	git_buf_rtrim(&orig_head_id);

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	if ((error = git_oid_fromstr(&rebase->orig_head_id, orig_head_id.ptr)) < 0)
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		goto done;

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	git_buf_truncate(&path, state_path_len);

	if ((error = git_buf_joinpath(&path, path.ptr, ONTO_FILE)) < 0 ||
		(error = git_futils_readbuffer(&onto_id, path.ptr)) < 0)
		goto done;

	git_buf_rtrim(&onto_id);

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	if ((error = git_oid_fromstr(&rebase->onto_id, onto_id.ptr)) < 0)
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		goto done;

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	if (!rebase->head_detached)
		rebase->orig_head_name = git_buf_detach(&orig_head_name);
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	switch (rebase->type) {
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	case GIT_REBASE_TYPE_INTERACTIVE:
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		giterr_set(GITERR_REBASE, "interactive rebase is not supported");
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		error = -1;
		break;
	case GIT_REBASE_TYPE_MERGE:
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		error = rebase_open_merge(rebase);
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		break;
	case GIT_REBASE_TYPE_APPLY:
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		giterr_set(GITERR_REBASE, "patch application rebase is not supported");
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		error = -1;
		break;
	default:
		abort();
	}

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done:
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	if (error == 0)
		*out = rebase;
	else
		git_rebase_free(rebase);

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	git_buf_dispose(&path);
	git_buf_dispose(&orig_head_name);
	git_buf_dispose(&orig_head_id);
	git_buf_dispose(&onto_id);
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	return error;
}

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static int rebase_cleanup(git_rebase *rebase)
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{
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	if (!rebase || rebase->inmemory)
		return 0;

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	return git_path_isdir(rebase->state_path) ?
		git_futils_rmdir_r(rebase->state_path, NULL, GIT_RMDIR_REMOVE_FILES) :
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		0;
}

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static int rebase_setupfile(git_rebase *rebase, const char *filename, int flags, const char *fmt, ...)
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{
	git_buf path = GIT_BUF_INIT,
		contents = GIT_BUF_INIT;
	va_list ap;
	int error;

	va_start(ap, fmt);
	git_buf_vprintf(&contents, fmt, ap);
	va_end(ap);

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	if ((error = git_buf_joinpath(&path, rebase->state_path, filename)) == 0)
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		error = git_futils_writebuffer(&contents, path.ptr, flags, REBASE_FILE_MODE);
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	git_buf_dispose(&path);
	git_buf_dispose(&contents);
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	return error;
}

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static const char *rebase_onto_name(const git_annotated_commit *onto)
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{
	if (onto->ref_name && git__strncmp(onto->ref_name, "refs/heads/", 11) == 0)
		return onto->ref_name + 11;
	else if (onto->ref_name)
		return onto->ref_name;
	else
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		return onto->id_str;
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}

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static int rebase_setupfiles_merge(git_rebase *rebase)
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{
	git_buf commit_filename = GIT_BUF_INIT;
	char id_str[GIT_OID_HEXSZ];
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	git_rebase_operation *operation;
	size_t i;
	int error = 0;
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	if ((error = rebase_setupfile(rebase, END_FILE, 0, "%" PRIuZ "\n", git_array_size(rebase->operations))) < 0 ||
		(error = rebase_setupfile(rebase, ONTO_NAME_FILE, 0, "%s\n", rebase->onto_name)) < 0)
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		goto done;

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	for (i = 0; i < git_array_size(rebase->operations); i++) {
		operation = git_array_get(rebase->operations, i);
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		git_buf_clear(&commit_filename);
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		git_buf_printf(&commit_filename, CMT_FILE_FMT, i+1);

		git_oid_fmt(id_str, &operation->id);
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		if ((error = rebase_setupfile(rebase, commit_filename.ptr, 0,
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				"%.*s\n", GIT_OID_HEXSZ, id_str)) < 0)
			goto done;
	}

done:
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	git_buf_dispose(&commit_filename);
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	return error;
}

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static int rebase_setupfiles(git_rebase *rebase)
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{
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	char onto[GIT_OID_HEXSZ], orig_head[GIT_OID_HEXSZ];
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	const char *orig_head_name;
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	git_oid_fmt(onto, &rebase->onto_id);
	git_oid_fmt(orig_head, &rebase->orig_head_id);
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	if (p_mkdir(rebase->state_path, REBASE_DIR_MODE) < 0) {
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		giterr_set(GITERR_OS, "failed to create rebase directory '%s'", rebase->state_path);
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		return -1;
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	}

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	orig_head_name = rebase->head_detached ? ORIG_DETACHED_HEAD :
		rebase->orig_head_name;

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	if (git_repository__set_orig_head(rebase->repo, &rebase->orig_head_id) < 0 ||
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		rebase_setupfile(rebase, HEAD_NAME_FILE, 0, "%s\n", orig_head_name) < 0 ||
		rebase_setupfile(rebase, ONTO_FILE, 0, "%.*s\n", GIT_OID_HEXSZ, onto) < 0 ||
		rebase_setupfile(rebase, ORIG_HEAD_FILE, 0, "%.*s\n", GIT_OID_HEXSZ, orig_head) < 0 ||
		rebase_setupfile(rebase, QUIET_FILE, 0, rebase->quiet ? "t\n" : "\n") < 0)
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		return -1;
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	return rebase_setupfiles_merge(rebase);
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}

int git_rebase_init_options(git_rebase_options *opts, unsigned int version)
{
	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
		opts, version, git_rebase_options, GIT_REBASE_OPTIONS_INIT);
	return 0;
}

static int rebase_ensure_not_in_progress(git_repository *repo)
{
	int error;
	git_rebase_type_t type;

	if ((error = rebase_state_type(&type, NULL, repo)) < 0)
		return error;

	if (type != GIT_REBASE_TYPE_NONE) {
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		giterr_set(GITERR_REBASE, "there is an existing rebase in progress");
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		return -1;
	}

	return 0;
}

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static int rebase_ensure_not_dirty(
	git_repository *repo,
	bool check_index,
	bool check_workdir,
	int fail_with)
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{
	git_tree *head = NULL;
	git_index *index = NULL;
	git_diff *diff = NULL;
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	int error = 0;
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	if (check_index) {
		if ((error = git_repository_head_tree(&head, repo)) < 0 ||
			(error = git_repository_index(&index, repo)) < 0 ||
			(error = git_diff_tree_to_index(&diff, repo, head, index, NULL)) < 0)
			goto done;
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		if (git_diff_num_deltas(diff) > 0) {
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			giterr_set(GITERR_REBASE, "uncommitted changes exist in index");
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			error = fail_with;
			goto done;
		}
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		git_diff_free(diff);
		diff = NULL;
	}
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	if (check_workdir) {
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		git_diff_options diff_opts = GIT_DIFF_OPTIONS_INIT;
		diff_opts.ignore_submodules = GIT_SUBMODULE_IGNORE_UNTRACKED;
		if ((error = git_diff_index_to_workdir(&diff, repo, index, &diff_opts)) < 0)
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			goto done;
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552
		if (git_diff_num_deltas(diff) > 0) {
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			giterr_set(GITERR_REBASE, "unstaged changes exist in workdir");
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			error = fail_with;
			goto done;
		}
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	}

done:
	git_diff_free(diff);
	git_index_free(index);
	git_tree_free(head);

	return error;
}

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static int rebase_init_operations(
	git_rebase *rebase,
	git_repository *repo,
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	const git_annotated_commit *branch,
	const git_annotated_commit *upstream,
	const git_annotated_commit *onto)
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{
	git_revwalk *revwalk = NULL;
	git_commit *commit;
	git_oid id;
	bool merge;
	git_rebase_operation *operation;
	int error;

	if (!upstream)
		upstream = onto;

	if ((error = git_revwalk_new(&revwalk, rebase->repo)) < 0 ||
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		(error = git_revwalk_push(revwalk, git_annotated_commit_id(branch))) < 0 ||
		(error = git_revwalk_hide(revwalk, git_annotated_commit_id(upstream))) < 0)
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		goto done;

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	git_revwalk_sorting(revwalk, GIT_SORT_REVERSE);
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	while ((error = git_revwalk_next(&id, revwalk)) == 0) {
		if ((error = git_commit_lookup(&commit, repo, &id)) < 0)
			goto done;

		merge = (git_commit_parentcount(commit) > 1);
		git_commit_free(commit);

		if (merge)
			continue;

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		operation = rebase_operation_alloc(rebase, GIT_REBASE_OPERATION_PICK, &id, NULL);
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		GITERR_CHECK_ALLOC(operation);
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	}

	error = 0;

done:
	git_revwalk_free(revwalk);
	return error;
}

static int rebase_init_merge(
	git_rebase *rebase,
	git_repository *repo,
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	const git_annotated_commit *branch,
	const git_annotated_commit *upstream,
	const git_annotated_commit *onto)
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{
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	git_reference *head_ref = NULL;
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	git_commit *onto_commit = NULL;
	git_buf reflog = GIT_BUF_INIT;
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	git_buf state_path = GIT_BUF_INIT;
	int error;

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	GIT_UNUSED(upstream);

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	if ((error = git_buf_joinpath(&state_path, repo->gitdir, REBASE_MERGE_DIR)) < 0)
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		goto done;

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	rebase->state_path = git_buf_detach(&state_path);
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	GITERR_CHECK_ALLOC(rebase->state_path);

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	if (branch->ref_name && strcmp(branch->ref_name, "HEAD")) {
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		rebase->orig_head_name = git__strdup(branch->ref_name);
		GITERR_CHECK_ALLOC(rebase->orig_head_name);
	} else {
		rebase->head_detached = 1;
	}
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	rebase->onto_name = git__strdup(rebase_onto_name(onto));
	GITERR_CHECK_ALLOC(rebase->onto_name);

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	rebase->quiet = rebase->options.quiet;
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	git_oid_cpy(&rebase->orig_head_id, git_annotated_commit_id(branch));
	git_oid_cpy(&rebase->onto_id, git_annotated_commit_id(onto));
647

648 649 650 651 652 653 654 655 656 657
	if ((error = rebase_setupfiles(rebase)) < 0 ||
		(error = git_buf_printf(&reflog,
			"rebase: checkout %s", rebase_onto_name(onto))) < 0 ||
		(error = git_commit_lookup(
			&onto_commit, repo, git_annotated_commit_id(onto))) < 0 ||
		(error = git_checkout_tree(repo,
			(git_object *)onto_commit, &rebase->options.checkout_options)) < 0 ||
		(error = git_reference_create(&head_ref, repo, GIT_HEAD_FILE,
			git_annotated_commit_id(onto), 1, reflog.ptr)) < 0)
		goto done;
658

659 660
done:
	git_reference_free(head_ref);
661
	git_commit_free(onto_commit);
662 663
	git_buf_dispose(&reflog);
	git_buf_dispose(&state_path);
664

665 666 667
	return error;
}

668 669 670 671 672 673 674 675 676 677 678 679 680 681
static int rebase_init_inmemory(
	git_rebase *rebase,
	git_repository *repo,
	const git_annotated_commit *branch,
	const git_annotated_commit *upstream,
	const git_annotated_commit *onto)
{
	GIT_UNUSED(branch);
	GIT_UNUSED(upstream);

	return git_commit_lookup(
		&rebase->last_commit, repo, git_annotated_commit_id(onto));
}

682 683
int git_rebase_init(
	git_rebase **out,
684
	git_repository *repo,
685 686 687
	const git_annotated_commit *branch,
	const git_annotated_commit *upstream,
	const git_annotated_commit *onto,
688
	const git_rebase_options *given_opts)
689
{
690
	git_rebase *rebase = NULL;
691
	git_annotated_commit *head_branch = NULL;
692
	git_reference *head_ref = NULL;
693
	bool inmemory = (given_opts && given_opts->inmemory);
694 695
	int error;

696
	assert(repo && (upstream || onto));
697

698 699 700 701 702
	*out = NULL;

	if (!onto)
		onto = upstream;

703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719
	if ((error = rebase_check_versions(given_opts)) < 0)
		goto done;

	if (!inmemory) {
		if ((error = git_repository__ensure_not_bare(repo, "rebase")) < 0 ||
			(error = rebase_ensure_not_in_progress(repo)) < 0 ||
			(error = rebase_ensure_not_dirty(repo, true, true, GIT_ERROR)) < 0)
			goto done;
	}

	if (!branch) {
		if ((error = git_repository_head(&head_ref, repo)) < 0 ||
			(error = git_annotated_commit_from_ref(&head_branch, repo, head_ref)) < 0)
			goto done;

		branch = head_branch;
	}
720

721 722
	if (rebase_alloc(&rebase, given_opts) < 0)
		return -1;
723

724 725 726 727 728
	rebase->repo = repo;
	rebase->inmemory = inmemory;
	rebase->type = GIT_REBASE_TYPE_MERGE;

	if ((error = rebase_init_operations(rebase, repo, branch, upstream, onto)) < 0)
729 730
		goto done;

731 732 733
	if (inmemory)
		error = rebase_init_inmemory(rebase, repo, branch, upstream, onto);
	else
734
		error = rebase_init_merge(rebase, repo, branch ,upstream, onto);
735 736 737

	if (error == 0)
		*out = rebase;
738 739

done:
740
	git_reference_free(head_ref);
741 742
	git_annotated_commit_free(head_branch);

743 744 745 746 747
	if (error < 0) {
		rebase_cleanup(rebase);
		git_rebase_free(rebase);
	}

748 749
	return error;
}
750

751
static void normalize_checkout_options_for_apply(
752
	git_checkout_options *checkout_opts,
753 754
	git_rebase *rebase,
	git_commit *current_commit)
755
{
756
	memcpy(checkout_opts, &rebase->options.checkout_options, sizeof(git_checkout_options));
757 758 759 760

	if (!checkout_opts->ancestor_label)
		checkout_opts->ancestor_label = "ancestor";

761
	if (rebase->type == GIT_REBASE_TYPE_MERGE) {
762
		if (!checkout_opts->our_label)
763
			checkout_opts->our_label = rebase->onto_name;
764

765 766
		if (!checkout_opts->their_label)
			checkout_opts->their_label = git_commit_summary(current_commit);
767 768 769 770 771
	} else {
		abort();
	}
}

772 773 774 775 776 777 778 779 780 781 782 783 784
GIT_INLINE(int) rebase_movenext(git_rebase *rebase)
{
	size_t next = rebase->started ? rebase->current + 1 : 0;

	if (next == git_array_size(rebase->operations))
		return GIT_ITEROVER;

	rebase->started = 1;
	rebase->current = next;

	return 0;
}

785
static int rebase_next_merge(
786
	git_rebase_operation **out,
787
	git_rebase *rebase)
788
{
789 790
	git_buf path = GIT_BUF_INIT;
	git_commit *current_commit = NULL, *parent_commit = NULL;
791 792
	git_tree *current_tree = NULL, *head_tree = NULL, *parent_tree = NULL;
	git_index *index = NULL;
793
	git_indexwriter indexwriter = GIT_INDEXWRITER_INIT;
794
	git_rebase_operation *operation;
795
	git_checkout_options checkout_opts;
796
	char current_idstr[GIT_OID_HEXSZ];
797 798 799
	unsigned int parent_count;
	int error;

800
	*out = NULL;
801

802
	operation = git_array_get(rebase->operations, rebase->current);
803

804 805
	if ((error = git_commit_lookup(&current_commit, rebase->repo, &operation->id)) < 0 ||
		(error = git_commit_tree(&current_tree, current_commit)) < 0 ||
806
		(error = git_repository_head_tree(&head_tree, rebase->repo)) < 0)
807 808
		goto done;

809
	if ((parent_count = git_commit_parentcount(current_commit)) > 1) {
810
		giterr_set(GITERR_REBASE, "cannot rebase a merge commit");
811 812 813
		error = -1;
		goto done;
	} else if (parent_count) {
814
		if ((error = git_commit_parent(&parent_commit, current_commit, 0)) < 0 ||
815 816 817 818
			(error = git_commit_tree(&parent_tree, parent_commit)) < 0)
			goto done;
	}

819 820
	git_oid_fmt(current_idstr, &operation->id);

821
	normalize_checkout_options_for_apply(&checkout_opts, rebase, current_commit);
822

823
	if ((error = git_indexwriter_init_for_operation(&indexwriter, rebase->repo, &checkout_opts.checkout_strategy)) < 0 ||
824 825
		(error = rebase_setupfile(rebase, MSGNUM_FILE, 0, "%" PRIuZ "\n", rebase->current+1)) < 0 ||
		(error = rebase_setupfile(rebase, CURRENT_FILE, 0, "%.*s\n", GIT_OID_HEXSZ, current_idstr)) < 0 ||
826
		(error = git_merge_trees(&index, rebase->repo, parent_tree, head_tree, current_tree, &rebase->options.merge_options)) < 0 ||
827
		(error = git_merge__check_result(rebase->repo, index)) < 0 ||
828 829
		(error = git_checkout_index(rebase->repo, index, &checkout_opts)) < 0 ||
		(error = git_indexwriter_commit(&indexwriter)) < 0)
830 831
		goto done;

832
	*out = operation;
833

834
done:
835
	git_indexwriter_cleanup(&indexwriter);
836 837 838 839 840
	git_index_free(index);
	git_tree_free(current_tree);
	git_tree_free(head_tree);
	git_tree_free(parent_tree);
	git_commit_free(parent_commit);
841
	git_commit_free(current_commit);
842
	git_buf_dispose(&path);
843 844 845 846

	return error;
}

847 848 849 850 851 852 853 854
static int rebase_next_inmemory(
	git_rebase_operation **out,
	git_rebase *rebase)
{
	git_commit *current_commit = NULL, *parent_commit = NULL;
	git_tree *current_tree = NULL, *head_tree = NULL, *parent_tree = NULL;
	git_rebase_operation *operation;
	git_index *index = NULL;
855
	unsigned int parent_count;
856 857 858 859 860 861 862
	int error;

	*out = NULL;

	operation = git_array_get(rebase->operations, rebase->current);

	if ((error = git_commit_lookup(&current_commit, rebase->repo, &operation->id)) < 0 ||
863 864 865 866
		(error = git_commit_tree(&current_tree, current_commit)) < 0)
		goto done;

	if ((parent_count = git_commit_parentcount(current_commit)) > 1) {
867
		giterr_set(GITERR_REBASE, "cannot rebase a merge commit");
868 869 870 871 872 873 874 875 876
		error = -1;
		goto done;
	} else if (parent_count) {
		if ((error = git_commit_parent(&parent_commit, current_commit, 0)) < 0 ||
			(error = git_commit_tree(&parent_tree, parent_commit)) < 0)
			goto done;
	}

	if ((error = git_commit_tree(&head_tree, rebase->last_commit)) < 0 ||
877
		(error = git_merge_trees(&index, rebase->repo, parent_tree, head_tree, current_tree, &rebase->options.merge_options)) < 0)
878 879
		goto done;

880 881 882 883 884 885 886
	if (!rebase->index) {
		rebase->index = index;
		index = NULL;
	} else {
		if ((error = git_index_read_index(rebase->index, index)) < 0)
			goto done;
	}
887 888 889 890 891 892 893 894 895 896 897 898 899 900

	*out = operation;

done:
	git_commit_free(current_commit);
	git_commit_free(parent_commit);
	git_tree_free(current_tree);
	git_tree_free(head_tree);
	git_tree_free(parent_tree);
	git_index_free(index);

	return error;
}

901
int git_rebase_next(
902
	git_rebase_operation **out,
903
	git_rebase *rebase)
904 905 906
{
	int error;

907
	assert(out && rebase);
908

909 910 911 912 913 914
	if ((error = rebase_movenext(rebase)) < 0)
		return error;

	if (rebase->inmemory)
		error = rebase_next_inmemory(out, rebase);
	else if (rebase->type == GIT_REBASE_TYPE_MERGE)
915
		error = rebase_next_merge(out, rebase);
916
	else
917 918
		abort();

919 920 921
	return error;
}

922 923 924 925 926 927 928 929 930 931 932 933
int git_rebase_inmemory_index(
	git_index **out,
	git_rebase *rebase)
{
	assert(out && rebase && rebase->index);

	GIT_REFCOUNT_INC(rebase->index);
	*out = rebase->index;

	return 0;
}

934 935
static int rebase_commit__create(
	git_commit **out,
936
	git_rebase *rebase,
937 938
	git_index *index,
	git_commit *parent_commit,
939 940 941 942 943
	const git_signature *author,
	const git_signature *committer,
	const char *message_encoding,
	const char *message)
{
944
	git_rebase_operation *operation;
945 946 947
	git_commit *current_commit = NULL, *commit = NULL;
	git_tree *parent_tree = NULL, *tree = NULL;
	git_oid tree_id, commit_id;
948 949
	int error;

950
	operation = git_array_get(rebase->operations, rebase->current);
951 952

	if (git_index_has_conflicts(index)) {
953
		giterr_set(GITERR_REBASE, "conflicts have not been resolved");
954
		error = GIT_EUNMERGED;
955 956 957
		goto done;
	}

958 959 960 961
	if ((error = git_commit_lookup(&current_commit, rebase->repo, &operation->id)) < 0 ||
		(error = git_commit_tree(&parent_tree, parent_commit)) < 0 ||
		(error = git_index_write_tree_to(&tree_id, index, rebase->repo)) < 0 ||
		(error = git_tree_lookup(&tree, rebase->repo, &tree_id)) < 0)
962 963
		goto done;

964 965
	if (git_oid_equal(&tree_id, git_tree_id(parent_tree))) {
		giterr_set(GITERR_REBASE, "this patch has already been applied");
966 967 968 969
		error = GIT_EAPPLIED;
		goto done;
	}

970
	if (!author)
971
		author = git_commit_author(current_commit);
972 973

	if (!message) {
974 975
		message_encoding = git_commit_message_encoding(current_commit);
		message = git_commit_message(current_commit);
976 977
	}

978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020
	if ((error = git_commit_create(&commit_id, rebase->repo, NULL, author,
		committer, message_encoding, message, tree, 1,
		(const git_commit **)&parent_commit)) < 0 ||
		(error = git_commit_lookup(&commit, rebase->repo, &commit_id)) < 0)
		goto done;

	*out = commit;

done:
	if (error < 0)
		git_commit_free(commit);

	git_commit_free(current_commit);
	git_tree_free(parent_tree);
	git_tree_free(tree);

	return error;
}

static int rebase_commit_merge(
	git_oid *commit_id,
	git_rebase *rebase,
	const git_signature *author,
	const git_signature *committer,
	const char *message_encoding,
	const char *message)
{
	git_rebase_operation *operation;
	git_reference *head = NULL;
	git_commit *head_commit = NULL, *commit = NULL;
	git_index *index = NULL;
	char old_idstr[GIT_OID_HEXSZ], new_idstr[GIT_OID_HEXSZ];
	int error;

	operation = git_array_get(rebase->operations, rebase->current);
	assert(operation);

	if ((error = rebase_ensure_not_dirty(rebase->repo, false, true, GIT_EUNMERGED)) < 0 ||
		(error = git_repository_head(&head, rebase->repo)) < 0 ||
		(error = git_reference_peel((git_object **)&head_commit, head, GIT_OBJ_COMMIT)) < 0 ||
		(error = git_repository_index(&index, rebase->repo)) < 0 ||
		(error = rebase_commit__create(&commit, rebase, index, head_commit,
			author, committer, message_encoding, message)) < 0 ||
1021
		(error = git_reference__update_for_commit(
1022
			rebase->repo, NULL, "HEAD", git_commit_id(commit), "rebase")) < 0)
1023 1024
		goto done;

1025 1026 1027 1028 1029 1030
	git_oid_fmt(old_idstr, &operation->id);
	git_oid_fmt(new_idstr, git_commit_id(commit));

	if ((error = rebase_setupfile(rebase, REWRITTEN_FILE, O_CREAT|O_WRONLY|O_APPEND,
		"%.*s %.*s\n", GIT_OID_HEXSZ, old_idstr, GIT_OID_HEXSZ, new_idstr)) < 0)
		goto done;
1031

1032
	git_oid_cpy(commit_id, git_commit_id(commit));
1033 1034 1035

done:
	git_index_free(index);
1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052
	git_reference_free(head);
	git_commit_free(head_commit);
	git_commit_free(commit);
	return error;
}

static int rebase_commit_inmemory(
	git_oid *commit_id,
	git_rebase *rebase,
	const git_signature *author,
	const git_signature *committer,
	const char *message_encoding,
	const char *message)
{
	git_commit *commit = NULL;
	int error = 0;

1053
	assert(rebase->index);
1054
	assert(rebase->last_commit);
1055
	assert(rebase->current < rebase->operations.size);
1056

1057
	if ((error = rebase_commit__create(&commit, rebase, rebase->index,
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068
		rebase->last_commit, author, committer, message_encoding, message)) < 0)
		goto done;

	git_commit_free(rebase->last_commit);
	rebase->last_commit = commit;

	git_oid_cpy(commit_id, git_commit_id(commit));

done:
	if (error < 0)
		git_commit_free(commit);
1069 1070 1071 1072 1073 1074

	return error;
}

int git_rebase_commit(
	git_oid *id,
1075
	git_rebase *rebase,
1076 1077 1078 1079 1080 1081 1082
	const git_signature *author,
	const git_signature *committer,
	const char *message_encoding,
	const char *message)
{
	int error;

1083
	assert(rebase && committer);
1084

1085 1086 1087 1088
	if (rebase->inmemory)
		error = rebase_commit_inmemory(
			id, rebase, author, committer, message_encoding, message);
	else if (rebase->type == GIT_REBASE_TYPE_MERGE)
1089
		error = rebase_commit_merge(
1090
			id, rebase, author, committer, message_encoding, message);
1091
	else
1092 1093
		abort();

1094 1095 1096
	return error;
}

1097
int git_rebase_abort(git_rebase *rebase)
1098 1099 1100 1101 1102
{
	git_reference *orig_head_ref = NULL;
	git_commit *orig_head_commit = NULL;
	int error;

1103
	assert(rebase);
1104

1105 1106 1107
	if (rebase->inmemory)
		return 0;

1108 1109
	error = rebase->head_detached ?
		git_reference_create(&orig_head_ref, rebase->repo, GIT_HEAD_FILE,
1110
			 &rebase->orig_head_id, 1, "rebase: aborting") :
1111
		git_reference_symbolic_create(
1112
			&orig_head_ref, rebase->repo, GIT_HEAD_FILE, rebase->orig_head_name, 1,
1113
			"rebase: aborting");
1114 1115 1116 1117 1118

	if (error < 0)
		goto done;

	if ((error = git_commit_lookup(
1119 1120
			&orig_head_commit, rebase->repo, &rebase->orig_head_id)) < 0 ||
		(error = git_reset(rebase->repo, (git_object *)orig_head_commit,
1121
			GIT_RESET_HARD, &rebase->options.checkout_options)) < 0)
1122 1123
		goto done;

1124
	error = rebase_cleanup(rebase);
1125 1126 1127 1128 1129 1130 1131

done:
	git_commit_free(orig_head_commit);
	git_reference_free(orig_head_ref);

	return error;
}
1132

1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163
static int notes_ref_lookup(git_buf *out, git_rebase *rebase)
{
	git_config *config = NULL;
	int do_rewrite, error;

	if (rebase->options.rewrite_notes_ref) {
		git_buf_attach_notowned(out,
			rebase->options.rewrite_notes_ref,
			strlen(rebase->options.rewrite_notes_ref));
		return 0;
	}

	if ((error = git_repository_config(&config, rebase->repo)) < 0 ||
		(error = git_config_get_bool(&do_rewrite, config, "notes.rewrite.rebase")) < 0) {

		if (error != GIT_ENOTFOUND)
			goto done;

		giterr_clear();
		do_rewrite = 1;
	}

	error = do_rewrite ?
		git_config_get_string_buf(out, config, "notes.rewriteref") :
		GIT_ENOTFOUND;

done:
	git_config_free(config);
	return error;
}

1164
static int rebase_copy_note(
1165
	git_rebase *rebase,
1166
	const char *notes_ref,
1167 1168
	git_oid *from,
	git_oid *to,
1169
	const git_signature *committer)
1170
{
1171 1172
	git_note *note = NULL;
	git_oid note_id;
1173
	git_signature *who = NULL;
1174 1175
	int error;

1176
	if ((error = git_note_read(&note, rebase->repo, notes_ref, from)) < 0) {
1177 1178 1179 1180 1181 1182 1183 1184
		if (error == GIT_ENOTFOUND) {
			giterr_clear();
			error = 0;
		}

		goto done;
	}

1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196
	if (!committer) {
		if((error = git_signature_default(&who, rebase->repo)) < 0) {
			if (error != GIT_ENOTFOUND ||
				(error = git_signature_now(&who, "unknown", "unknown")) < 0)
				goto done;

			giterr_clear();
		}

		committer = who;
	}

1197
	error = git_note_create(&note_id, rebase->repo, notes_ref,
1198
		git_note_author(note), committer, to, git_note_message(note), 0);
1199 1200 1201

done:
	git_note_free(note);
1202
	git_signature_free(who);
1203 1204 1205 1206 1207

	return error;
}

static int rebase_copy_notes(
1208
	git_rebase *rebase,
1209
	const git_signature *committer)
1210
{
1211
	git_buf path = GIT_BUF_INIT, rewritten = GIT_BUF_INIT, notes_ref = GIT_BUF_INIT;
1212 1213 1214 1215 1216
	char *pair_list, *fromstr, *tostr, *end;
	git_oid from, to;
	unsigned int linenum = 1;
	int error = 0;

1217 1218 1219 1220 1221 1222
	if ((error = notes_ref_lookup(&notes_ref, rebase)) < 0) {
		if (error == GIT_ENOTFOUND) {
			giterr_clear();
			error = 0;
		}

1223
		goto done;
1224
	}
1225

1226
	if ((error = git_buf_joinpath(&path, rebase->state_path, REWRITTEN_FILE)) < 0 ||
1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252
		(error = git_futils_readbuffer(&rewritten, path.ptr)) < 0)
		goto done;

	pair_list = rewritten.ptr;

	while (*pair_list) {
		fromstr = pair_list;

		if ((end = strchr(fromstr, '\n')) == NULL)
			goto on_error;

		pair_list = end+1;
		*end = '\0';

		if ((end = strchr(fromstr, ' ')) == NULL)
			goto on_error;

		tostr = end+1;
		*end = '\0';

		if (strlen(fromstr) != GIT_OID_HEXSZ ||
			strlen(tostr) != GIT_OID_HEXSZ ||
			git_oid_fromstr(&from, fromstr) < 0 ||
			git_oid_fromstr(&to, tostr) < 0)
			goto on_error;

1253
		if ((error = rebase_copy_note(rebase, notes_ref.ptr, &from, &to, committer)) < 0)
1254 1255 1256 1257 1258 1259 1260 1261
			goto done;

		linenum++;
	}

	goto done;

on_error:
1262
	giterr_set(GITERR_REBASE, "invalid rewritten file at line %d", linenum);
1263 1264 1265
	error = -1;

done:
1266 1267 1268
	git_buf_dispose(&rewritten);
	git_buf_dispose(&path);
	git_buf_dispose(&notes_ref);
1269 1270 1271 1272

	return error;
}

1273
static int return_to_orig_head(git_rebase *rebase)
1274
{
1275 1276 1277 1278
	git_reference *terminal_ref = NULL, *branch_ref = NULL, *head_ref = NULL;
	git_commit *terminal_commit = NULL;
	git_buf branch_msg = GIT_BUF_INIT, head_msg = GIT_BUF_INIT;
	char onto[GIT_OID_HEXSZ];
1279
	int error = 0;
1280

1281
	git_oid_fmt(onto, &rebase->onto_id);
1282

1283 1284 1285 1286 1287 1288 1289
	if ((error = git_buf_printf(&branch_msg,
			"rebase finished: %s onto %.*s",
			rebase->orig_head_name, GIT_OID_HEXSZ, onto)) == 0 &&
		(error = git_buf_printf(&head_msg,
			"rebase finished: returning to %s",
			rebase->orig_head_name)) == 0 &&
		(error = git_repository_head(&terminal_ref, rebase->repo)) == 0 &&
1290
		(error = git_reference_peel((git_object **)&terminal_commit,
1291
			terminal_ref, GIT_OBJ_COMMIT)) == 0 &&
1292
		(error = git_reference_create_matching(&branch_ref,
1293 1294 1295 1296
			rebase->repo, rebase->orig_head_name,
			git_commit_id(terminal_commit), 1,
			&rebase->orig_head_id, branch_msg.ptr)) == 0)
		error = git_reference_symbolic_create(&head_ref,
1297
			rebase->repo, GIT_HEAD_FILE, rebase->orig_head_name, 1,
1298
			head_msg.ptr);
1299

1300 1301
	git_buf_dispose(&head_msg);
	git_buf_dispose(&branch_msg);
1302 1303 1304 1305 1306 1307 1308 1309
	git_commit_free(terminal_commit);
	git_reference_free(head_ref);
	git_reference_free(branch_ref);
	git_reference_free(terminal_ref);

	return error;
}

1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329
int git_rebase_finish(
	git_rebase *rebase,
	const git_signature *signature)
{
	int error = 0;

	assert(rebase);

	if (rebase->inmemory)
		return 0;

	if (!rebase->head_detached)
		error = return_to_orig_head(rebase);

	if (error == 0 && (error = rebase_copy_notes(rebase, signature)) == 0)
		error = rebase_cleanup(rebase);

	return error;
}

1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340
size_t git_rebase_operation_entrycount(git_rebase *rebase)
{
	assert(rebase);

	return git_array_size(rebase->operations);
}

size_t git_rebase_operation_current(git_rebase *rebase)
{
	assert(rebase);

1341
	return rebase->started ? rebase->current : GIT_REBASE_NO_OPERATION;
1342 1343 1344 1345 1346 1347 1348 1349 1350
}

git_rebase_operation *git_rebase_operation_byindex(git_rebase *rebase, size_t idx)
{
	assert(rebase);

	return git_array_get(rebase->operations, idx);
}

1351 1352 1353 1354 1355
void git_rebase_free(git_rebase *rebase)
{
	if (rebase == NULL)
		return;

1356
	git_index_free(rebase->index);
1357
	git_commit_free(rebase->last_commit);
1358
	git__free(rebase->onto_name);
1359 1360
	git__free(rebase->orig_head_name);
	git__free(rebase->state_path);
1361
	git_array_clear(rebase->operations);
1362
	git__free((char *)rebase->options.rewrite_notes_ref);
1363
	git__free(rebase);
1364
}