From: Junio C Hamano <gitster@pobox.com>
Date: Mon, 15 Dec 2008 10:41:24 +0000 (-0800)
Subject: Merge branch 'cb/maint-merge-recursive-fix' into cb/merge-recursive-fix
X-Git-Tag: v1.6.2-rc0~186^2
X-Git-Url: https://git.tokkee.org/?a=commitdiff_plain;h=60c91181faf33316211970cd2f332b39acb48399;p=git.git

Merge branch 'cb/maint-merge-recursive-fix' into cb/merge-recursive-fix

* cb/maint-merge-recursive-fix:
  merge-recursive: do not clobber untracked working tree garbage
  modify/delete conflict resolution overwrites untracked file
---

60c91181faf33316211970cd2f332b39acb48399
diff --cc merge-recursive.c
index a0c804c81,000000000..2da433343
mode 100644,000000..100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@@ -1,1356 -1,0 +1,1388 @@@
 +/*
 + * Recursive Merge algorithm stolen from git-merge-recursive.py by
 + * Fredrik Kuivinen.
 + * The thieves were Alex Riesen and Johannes Schindelin, in June/July 2006
 + */
 +#include "cache.h"
 +#include "cache-tree.h"
 +#include "commit.h"
 +#include "blob.h"
 +#include "builtin.h"
 +#include "tree-walk.h"
 +#include "diff.h"
 +#include "diffcore.h"
 +#include "tag.h"
 +#include "unpack-trees.h"
 +#include "string-list.h"
 +#include "xdiff-interface.h"
 +#include "ll-merge.h"
 +#include "attr.h"
 +#include "merge-recursive.h"
 +#include "dir.h"
 +
 +static struct tree *shift_tree_object(struct tree *one, struct tree *two)
 +{
 +	unsigned char shifted[20];
 +
 +	/*
 +	 * NEEDSWORK: this limits the recursion depth to hardcoded
 +	 * value '2' to avoid excessive overhead.
 +	 */
 +	shift_tree(one->object.sha1, two->object.sha1, shifted, 2);
 +	if (!hashcmp(two->object.sha1, shifted))
 +		return two;
 +	return lookup_tree(shifted);
 +}
 +
 +/*
 + * A virtual commit has (const char *)commit->util set to the name.
 + */
 +
 +struct commit *make_virtual_commit(struct tree *tree, const char *comment)
 +{
 +	struct commit *commit = xcalloc(1, sizeof(struct commit));
 +	commit->tree = tree;
 +	commit->util = (void*)comment;
 +	/* avoid warnings */
 +	commit->object.parsed = 1;
 +	return commit;
 +}
 +
 +/*
 + * Since we use get_tree_entry(), which does not put the read object into
 + * the object pool, we cannot rely on a == b.
 + */
 +static int sha_eq(const unsigned char *a, const unsigned char *b)
 +{
 +	if (!a && !b)
 +		return 2;
 +	return a && b && hashcmp(a, b) == 0;
 +}
 +
 +/*
 + * Since we want to write the index eventually, we cannot reuse the index
 + * for these (temporary) data.
 + */
 +struct stage_data
 +{
 +	struct
 +	{
 +		unsigned mode;
 +		unsigned char sha[20];
 +	} stages[4];
 +	unsigned processed:1;
 +};
 +
 +static int show(struct merge_options *o, int v)
 +{
 +	return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 +}
 +
 +static void flush_output(struct merge_options *o)
 +{
 +	if (o->obuf.len) {
 +		fputs(o->obuf.buf, stdout);
 +		strbuf_reset(&o->obuf);
 +	}
 +}
 +
 +static void output(struct merge_options *o, int v, const char *fmt, ...)
 +{
 +	int len;
 +	va_list ap;
 +
 +	if (!show(o, v))
 +		return;
 +
 +	strbuf_grow(&o->obuf, o->call_depth * 2 + 2);
 +	memset(o->obuf.buf + o->obuf.len, ' ', o->call_depth * 2);
 +	strbuf_setlen(&o->obuf, o->obuf.len + o->call_depth * 2);
 +
 +	va_start(ap, fmt);
 +	len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 +	va_end(ap);
 +
 +	if (len < 0)
 +		len = 0;
 +	if (len >= strbuf_avail(&o->obuf)) {
 +		strbuf_grow(&o->obuf, len + 2);
 +		va_start(ap, fmt);
 +		len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 +		va_end(ap);
 +		if (len >= strbuf_avail(&o->obuf)) {
 +			die("this should not happen, your snprintf is broken");
 +		}
 +	}
 +	strbuf_setlen(&o->obuf, o->obuf.len + len);
 +	strbuf_add(&o->obuf, "\n", 1);
 +	if (!o->buffer_output)
 +		flush_output(o);
 +}
 +
 +static void output_commit_title(struct merge_options *o, struct commit *commit)
 +{
 +	int i;
 +	flush_output(o);
 +	for (i = o->call_depth; i--;)
 +		fputs("  ", stdout);
 +	if (commit->util)
 +		printf("virtual %s\n", (char *)commit->util);
 +	else {
 +		printf("%s ", find_unique_abbrev(commit->object.sha1, DEFAULT_ABBREV));
 +		if (parse_commit(commit) != 0)
 +			printf("(bad commit)\n");
 +		else {
 +			const char *s;
 +			int len;
 +			for (s = commit->buffer; *s; s++)
 +				if (*s == '\n' && s[1] == '\n') {
 +					s += 2;
 +					break;
 +				}
 +			for (len = 0; s[len] && '\n' != s[len]; len++)
 +				; /* do nothing */
 +			printf("%.*s\n", len, s);
 +		}
 +	}
 +}
 +
 +static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 +		const char *path, int stage, int refresh, int options)
 +{
 +	struct cache_entry *ce;
 +	ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 +	if (!ce)
 +		return error("addinfo_cache failed for path '%s'", path);
 +	return add_cache_entry(ce, options);
 +}
 +
 +static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 +{
 +	parse_tree(tree);
 +	init_tree_desc(desc, tree->buffer, tree->size);
 +}
 +
 +static int git_merge_trees(int index_only,
 +			   struct tree *common,
 +			   struct tree *head,
 +			   struct tree *merge)
 +{
 +	int rc;
 +	struct tree_desc t[3];
 +	struct unpack_trees_options opts;
 +
 +	memset(&opts, 0, sizeof(opts));
 +	if (index_only)
 +		opts.index_only = 1;
 +	else
 +		opts.update = 1;
 +	opts.merge = 1;
 +	opts.head_idx = 2;
 +	opts.fn = threeway_merge;
 +	opts.src_index = &the_index;
 +	opts.dst_index = &the_index;
 +
 +	init_tree_desc_from_tree(t+0, common);
 +	init_tree_desc_from_tree(t+1, head);
 +	init_tree_desc_from_tree(t+2, merge);
 +
 +	rc = unpack_trees(3, t, &opts);
 +	cache_tree_free(&active_cache_tree);
 +	return rc;
 +}
 +
 +struct tree *write_tree_from_memory(struct merge_options *o)
 +{
 +	struct tree *result = NULL;
 +
 +	if (unmerged_cache()) {
 +		int i;
 +		output(o, 0, "There are unmerged index entries:");
 +		for (i = 0; i < active_nr; i++) {
 +			struct cache_entry *ce = active_cache[i];
 +			if (ce_stage(ce))
 +				output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
 +		}
 +		return NULL;
 +	}
 +
 +	if (!active_cache_tree)
 +		active_cache_tree = cache_tree();
 +
 +	if (!cache_tree_fully_valid(active_cache_tree) &&
 +	    cache_tree_update(active_cache_tree,
 +			      active_cache, active_nr, 0, 0) < 0)
 +		die("error building trees");
 +
 +	result = lookup_tree(active_cache_tree->sha1);
 +
 +	return result;
 +}
 +
 +static int save_files_dirs(const unsigned char *sha1,
 +		const char *base, int baselen, const char *path,
 +		unsigned int mode, int stage, void *context)
 +{
 +	int len = strlen(path);
 +	char *newpath = xmalloc(baselen + len + 1);
 +	struct merge_options *o = context;
 +
 +	memcpy(newpath, base, baselen);
 +	memcpy(newpath + baselen, path, len);
 +	newpath[baselen + len] = '\0';
 +
 +	if (S_ISDIR(mode))
 +		string_list_insert(newpath, &o->current_directory_set);
 +	else
 +		string_list_insert(newpath, &o->current_file_set);
 +	free(newpath);
 +
 +	return READ_TREE_RECURSIVE;
 +}
 +
 +static int get_files_dirs(struct merge_options *o, struct tree *tree)
 +{
 +	int n;
 +	if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 +		return 0;
 +	n = o->current_file_set.nr + o->current_directory_set.nr;
 +	return n;
 +}
 +
 +/*
 + * Returns an index_entry instance which doesn't have to correspond to
 + * a real cache entry in Git's index.
 + */
 +static struct stage_data *insert_stage_data(const char *path,
 +		struct tree *o, struct tree *a, struct tree *b,
 +		struct string_list *entries)
 +{
 +	struct string_list_item *item;
 +	struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
 +	get_tree_entry(o->object.sha1, path,
 +			e->stages[1].sha, &e->stages[1].mode);
 +	get_tree_entry(a->object.sha1, path,
 +			e->stages[2].sha, &e->stages[2].mode);
 +	get_tree_entry(b->object.sha1, path,
 +			e->stages[3].sha, &e->stages[3].mode);
 +	item = string_list_insert(path, entries);
 +	item->util = e;
 +	return e;
 +}
 +
 +/*
 + * Create a dictionary mapping file names to stage_data objects. The
 + * dictionary contains one entry for every path with a non-zero stage entry.
 + */
 +static struct string_list *get_unmerged(void)
 +{
 +	struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 +	int i;
 +
 +	unmerged->strdup_strings = 1;
 +
 +	for (i = 0; i < active_nr; i++) {
 +		struct string_list_item *item;
 +		struct stage_data *e;
 +		struct cache_entry *ce = active_cache[i];
 +		if (!ce_stage(ce))
 +			continue;
 +
 +		item = string_list_lookup(ce->name, unmerged);
 +		if (!item) {
 +			item = string_list_insert(ce->name, unmerged);
 +			item->util = xcalloc(1, sizeof(struct stage_data));
 +		}
 +		e = item->util;
 +		e->stages[ce_stage(ce)].mode = ce->ce_mode;
 +		hashcpy(e->stages[ce_stage(ce)].sha, ce->sha1);
 +	}
 +
 +	return unmerged;
 +}
 +
 +struct rename
 +{
 +	struct diff_filepair *pair;
 +	struct stage_data *src_entry;
 +	struct stage_data *dst_entry;
 +	unsigned processed:1;
 +};
 +
 +/*
 + * Get information of all renames which occurred between 'o_tree' and
 + * 'tree'. We need the three trees in the merge ('o_tree', 'a_tree' and
 + * 'b_tree') to be able to associate the correct cache entries with
 + * the rename information. 'tree' is always equal to either a_tree or b_tree.
 + */
 +static struct string_list *get_renames(struct merge_options *o,
 +				       struct tree *tree,
 +				       struct tree *o_tree,
 +				       struct tree *a_tree,
 +				       struct tree *b_tree,
 +				       struct string_list *entries)
 +{
 +	int i;
 +	struct string_list *renames;
 +	struct diff_options opts;
 +
 +	renames = xcalloc(1, sizeof(struct string_list));
 +	diff_setup(&opts);
 +	DIFF_OPT_SET(&opts, RECURSIVE);
 +	opts.detect_rename = DIFF_DETECT_RENAME;
 +	opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
 +			    o->diff_rename_limit >= 0 ? o->diff_rename_limit :
 +			    500;
 +	opts.warn_on_too_large_rename = 1;
 +	opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 +	if (diff_setup_done(&opts) < 0)
 +		die("diff setup failed");
 +	diff_tree_sha1(o_tree->object.sha1, tree->object.sha1, "", &opts);
 +	diffcore_std(&opts);
 +	for (i = 0; i < diff_queued_diff.nr; ++i) {
 +		struct string_list_item *item;
 +		struct rename *re;
 +		struct diff_filepair *pair = diff_queued_diff.queue[i];
 +		if (pair->status != 'R') {
 +			diff_free_filepair(pair);
 +			continue;
 +		}
 +		re = xmalloc(sizeof(*re));
 +		re->processed = 0;
 +		re->pair = pair;
 +		item = string_list_lookup(re->pair->one->path, entries);
 +		if (!item)
 +			re->src_entry = insert_stage_data(re->pair->one->path,
 +					o_tree, a_tree, b_tree, entries);
 +		else
 +			re->src_entry = item->util;
 +
 +		item = string_list_lookup(re->pair->two->path, entries);
 +		if (!item)
 +			re->dst_entry = insert_stage_data(re->pair->two->path,
 +					o_tree, a_tree, b_tree, entries);
 +		else
 +			re->dst_entry = item->util;
 +		item = string_list_insert(pair->one->path, renames);
 +		item->util = re;
 +	}
 +	opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 +	diff_queued_diff.nr = 0;
 +	diff_flush(&opts);
 +	return renames;
 +}
 +
 +static int update_stages(const char *path, struct diff_filespec *o,
 +			 struct diff_filespec *a, struct diff_filespec *b,
 +			 int clear)
 +{
 +	int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 +	if (clear)
 +		if (remove_file_from_cache(path))
 +			return -1;
 +	if (o)
 +		if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 +			return -1;
 +	if (a)
 +		if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
 +			return -1;
 +	if (b)
 +		if (add_cacheinfo(b->mode, b->sha1, path, 3, 0, options))
 +			return -1;
 +	return 0;
 +}
 +
 +static int remove_file(struct merge_options *o, int clean,
 +		       const char *path, int no_wd)
 +{
 +	int update_cache = o->call_depth || clean;
 +	int update_working_directory = !o->call_depth && !no_wd;
 +
 +	if (update_cache) {
 +		if (remove_file_from_cache(path))
 +			return -1;
 +	}
 +	if (update_working_directory) {
 +		if (remove_path(path) && errno != ENOENT)
 +			return -1;
 +	}
 +	return 0;
 +}
 +
 +static char *unique_path(struct merge_options *o, const char *path, const char *branch)
 +{
 +	char *newpath = xmalloc(strlen(path) + 1 + strlen(branch) + 8 + 1);
 +	int suffix = 0;
 +	struct stat st;
 +	char *p = newpath + strlen(path);
 +	strcpy(newpath, path);
 +	*(p++) = '~';
 +	strcpy(p, branch);
 +	for (; *p; ++p)
 +		if ('/' == *p)
 +			*p = '_';
 +	while (string_list_has_string(&o->current_file_set, newpath) ||
 +	       string_list_has_string(&o->current_directory_set, newpath) ||
 +	       lstat(newpath, &st) == 0)
 +		sprintf(p, "_%d", suffix++);
 +
 +	string_list_insert(newpath, &o->current_file_set);
 +	return newpath;
 +}
 +
 +static void flush_buffer(int fd, const char *buf, unsigned long size)
 +{
 +	while (size > 0) {
 +		long ret = write_in_full(fd, buf, size);
 +		if (ret < 0) {
 +			/* Ignore epipe */
 +			if (errno == EPIPE)
 +				break;
 +			die("merge-recursive: %s", strerror(errno));
 +		} else if (!ret) {
 +			die("merge-recursive: disk full?");
 +		}
 +		size -= ret;
 +		buf += ret;
 +	}
 +}
 +
++static int would_lose_untracked(const char *path)
++{
++	int pos = cache_name_pos(path, strlen(path));
++
++	if (pos < 0)
++		pos = -1 - pos;
++	while (pos < active_nr &&
++	       !strcmp(path, active_cache[pos]->name)) {
++		/*
++		 * If stage #0, it is definitely tracked.
++		 * If it has stage #2 then it was tracked
++		 * before this merge started.  All other
++		 * cases the path was not tracked.
++		 */
++		switch (ce_stage(active_cache[pos])) {
++		case 0:
++		case 2:
++			return 0;
++		}
++		pos++;
++	}
++	return file_exists(path);
++}
++
 +static int make_room_for_path(const char *path)
 +{
 +	int status;
 +	const char *msg = "failed to create path '%s'%s";
 +
 +	status = safe_create_leading_directories_const(path);
 +	if (status) {
 +		if (status == -3) {
 +			/* something else exists */
 +			error(msg, path, ": perhaps a D/F conflict?");
 +			return -1;
 +		}
 +		die(msg, path, "");
 +	}
 +
++	/*
++	 * Do not unlink a file in the work tree if we are not
++	 * tracking it.
++	 */
++	if (would_lose_untracked(path))
++		return error("refusing to lose untracked file at '%s'",
++			     path);
++
 +	/* Successful unlink is good.. */
 +	if (!unlink(path))
 +		return 0;
 +	/* .. and so is no existing file */
 +	if (errno == ENOENT)
 +		return 0;
 +	/* .. but not some other error (who really cares what?) */
 +	return error(msg, path, ": perhaps a D/F conflict?");
 +}
 +
 +static void update_file_flags(struct merge_options *o,
 +			      const unsigned char *sha,
 +			      unsigned mode,
 +			      const char *path,
 +			      int update_cache,
 +			      int update_wd)
 +{
 +	if (o->call_depth)
 +		update_wd = 0;
 +
 +	if (update_wd) {
 +		enum object_type type;
 +		void *buf;
 +		unsigned long size;
 +
 +		if (S_ISGITLINK(mode))
 +			die("cannot read object %s '%s': It is a submodule!",
 +			    sha1_to_hex(sha), path);
 +
 +		buf = read_sha1_file(sha, &type, &size);
 +		if (!buf)
 +			die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 +		if (type != OBJ_BLOB)
 +			die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 +		if (S_ISREG(mode)) {
 +			struct strbuf strbuf = STRBUF_INIT;
 +			if (convert_to_working_tree(path, buf, size, &strbuf)) {
 +				free(buf);
 +				size = strbuf.len;
 +				buf = strbuf_detach(&strbuf, NULL);
 +			}
 +		}
 +
 +		if (make_room_for_path(path) < 0) {
 +			update_wd = 0;
 +			free(buf);
 +			goto update_index;
 +		}
 +		if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 +			int fd;
 +			if (mode & 0100)
 +				mode = 0777;
 +			else
 +				mode = 0666;
 +			fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
 +			if (fd < 0)
 +				die("failed to open %s: %s", path, strerror(errno));
 +			flush_buffer(fd, buf, size);
 +			close(fd);
 +		} else if (S_ISLNK(mode)) {
 +			char *lnk = xmemdupz(buf, size);
 +			safe_create_leading_directories_const(path);
 +			unlink(path);
 +			if (symlink(lnk, path))
 +				die("failed to symlink %s: %s", path, strerror(errno));
 +			free(lnk);
 +		} else
 +			die("do not know what to do with %06o %s '%s'",
 +			    mode, sha1_to_hex(sha), path);
 +		free(buf);
 +	}
 + update_index:
 +	if (update_cache)
 +		add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 +}
 +
 +static void update_file(struct merge_options *o,
 +			int clean,
 +			const unsigned char *sha,
 +			unsigned mode,
 +			const char *path)
 +{
 +	update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 +}
 +
 +/* Low level file merging, update and removal */
 +
 +struct merge_file_info
 +{
 +	unsigned char sha[20];
 +	unsigned mode;
 +	unsigned clean:1,
 +		 merge:1;
 +};
 +
 +static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 +{
 +	unsigned long size;
 +	enum object_type type;
 +
 +	if (!hashcmp(sha1, null_sha1)) {
 +		mm->ptr = xstrdup("");
 +		mm->size = 0;
 +		return;
 +	}
 +
 +	mm->ptr = read_sha1_file(sha1, &type, &size);
 +	if (!mm->ptr || type != OBJ_BLOB)
 +		die("unable to read blob object %s", sha1_to_hex(sha1));
 +	mm->size = size;
 +}
 +
 +static int merge_3way(struct merge_options *o,
 +		      mmbuffer_t *result_buf,
 +		      struct diff_filespec *one,
 +		      struct diff_filespec *a,
 +		      struct diff_filespec *b,
 +		      const char *branch1,
 +		      const char *branch2)
 +{
 +	mmfile_t orig, src1, src2;
 +	char *name1, *name2;
 +	int merge_status;
 +
 +	name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 +	name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 +
 +	fill_mm(one->sha1, &orig);
 +	fill_mm(a->sha1, &src1);
 +	fill_mm(b->sha1, &src2);
 +
 +	merge_status = ll_merge(result_buf, a->path, &orig,
 +				&src1, name1, &src2, name2,
 +				o->call_depth);
 +
 +	free(name1);
 +	free(name2);
 +	free(orig.ptr);
 +	free(src1.ptr);
 +	free(src2.ptr);
 +	return merge_status;
 +}
 +
 +static struct merge_file_info merge_file(struct merge_options *o,
 +				         struct diff_filespec *one,
 +					 struct diff_filespec *a,
 +					 struct diff_filespec *b,
 +					 const char *branch1,
 +					 const char *branch2)
 +{
 +	struct merge_file_info result;
 +	result.merge = 0;
 +	result.clean = 1;
 +
 +	if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
 +		result.clean = 0;
 +		if (S_ISREG(a->mode)) {
 +			result.mode = a->mode;
 +			hashcpy(result.sha, a->sha1);
 +		} else {
 +			result.mode = b->mode;
 +			hashcpy(result.sha, b->sha1);
 +		}
 +	} else {
 +		if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 +			result.merge = 1;
 +
 +		/*
 +		 * Merge modes
 +		 */
 +		if (a->mode == b->mode || a->mode == one->mode)
 +			result.mode = b->mode;
 +		else {
 +			result.mode = a->mode;
 +			if (b->mode != one->mode) {
 +				result.clean = 0;
 +				result.merge = 1;
 +			}
 +		}
 +
 +		if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 +			hashcpy(result.sha, b->sha1);
 +		else if (sha_eq(b->sha1, one->sha1))
 +			hashcpy(result.sha, a->sha1);
 +		else if (S_ISREG(a->mode)) {
 +			mmbuffer_t result_buf;
 +			int merge_status;
 +
 +			merge_status = merge_3way(o, &result_buf, one, a, b,
 +						  branch1, branch2);
 +
 +			if ((merge_status < 0) || !result_buf.ptr)
 +				die("Failed to execute internal merge");
 +
 +			if (write_sha1_file(result_buf.ptr, result_buf.size,
 +					    blob_type, result.sha))
 +				die("Unable to add %s to database",
 +				    a->path);
 +
 +			free(result_buf.ptr);
 +			result.clean = (merge_status == 0);
 +		} else if (S_ISGITLINK(a->mode)) {
 +			result.clean = 0;
 +			hashcpy(result.sha, a->sha1);
 +		} else if (S_ISLNK(a->mode)) {
 +			hashcpy(result.sha, a->sha1);
 +
 +			if (!sha_eq(a->sha1, b->sha1))
 +				result.clean = 0;
 +		} else {
 +			die("unsupported object type in the tree");
 +		}
 +	}
 +
 +	return result;
 +}
 +
 +static void conflict_rename_rename(struct merge_options *o,
 +				   struct rename *ren1,
 +				   const char *branch1,
 +				   struct rename *ren2,
 +				   const char *branch2)
 +{
 +	char *del[2];
 +	int delp = 0;
 +	const char *ren1_dst = ren1->pair->two->path;
 +	const char *ren2_dst = ren2->pair->two->path;
 +	const char *dst_name1 = ren1_dst;
 +	const char *dst_name2 = ren2_dst;
 +	if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 +		dst_name1 = del[delp++] = unique_path(o, ren1_dst, branch1);
 +		output(o, 1, "%s is a directory in %s adding as %s instead",
 +		       ren1_dst, branch2, dst_name1);
 +		remove_file(o, 0, ren1_dst, 0);
 +	}
 +	if (string_list_has_string(&o->current_directory_set, ren2_dst)) {
 +		dst_name2 = del[delp++] = unique_path(o, ren2_dst, branch2);
 +		output(o, 1, "%s is a directory in %s adding as %s instead",
 +		       ren2_dst, branch1, dst_name2);
 +		remove_file(o, 0, ren2_dst, 0);
 +	}
 +	if (o->call_depth) {
 +		remove_file_from_cache(dst_name1);
 +		remove_file_from_cache(dst_name2);
 +		/*
 +		 * Uncomment to leave the conflicting names in the resulting tree
 +		 *
 +		 * update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
 +		 * update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
 +		 */
 +	} else {
 +		update_stages(dst_name1, NULL, ren1->pair->two, NULL, 1);
 +		update_stages(dst_name2, NULL, NULL, ren2->pair->two, 1);
 +	}
 +	while (delp--)
 +		free(del[delp]);
 +}
 +
 +static void conflict_rename_dir(struct merge_options *o,
 +				struct rename *ren1,
 +				const char *branch1)
 +{
 +	char *new_path = unique_path(o, ren1->pair->two->path, branch1);
 +	output(o, 1, "Renaming %s to %s instead", ren1->pair->one->path, new_path);
 +	remove_file(o, 0, ren1->pair->two->path, 0);
 +	update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 +	free(new_path);
 +}
 +
 +static void conflict_rename_rename_2(struct merge_options *o,
 +				     struct rename *ren1,
 +				     const char *branch1,
 +				     struct rename *ren2,
 +				     const char *branch2)
 +{
 +	char *new_path1 = unique_path(o, ren1->pair->two->path, branch1);
 +	char *new_path2 = unique_path(o, ren2->pair->two->path, branch2);
 +	output(o, 1, "Renaming %s to %s and %s to %s instead",
 +	       ren1->pair->one->path, new_path1,
 +	       ren2->pair->one->path, new_path2);
 +	remove_file(o, 0, ren1->pair->two->path, 0);
 +	update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
 +	update_file(o, 0, ren2->pair->two->sha1, ren2->pair->two->mode, new_path2);
 +	free(new_path2);
 +	free(new_path1);
 +}
 +
 +static int process_renames(struct merge_options *o,
 +			   struct string_list *a_renames,
 +			   struct string_list *b_renames)
 +{
 +	int clean_merge = 1, i, j;
 +	struct string_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
 +	const struct rename *sre;
 +
 +	for (i = 0; i < a_renames->nr; i++) {
 +		sre = a_renames->items[i].util;
 +		string_list_insert(sre->pair->two->path, &a_by_dst)->util
 +			= sre->dst_entry;
 +	}
 +	for (i = 0; i < b_renames->nr; i++) {
 +		sre = b_renames->items[i].util;
 +		string_list_insert(sre->pair->two->path, &b_by_dst)->util
 +			= sre->dst_entry;
 +	}
 +
 +	for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
 +		int compare;
 +		char *src;
 +		struct string_list *renames1, *renames2, *renames2Dst;
 +		struct rename *ren1 = NULL, *ren2 = NULL;
 +		const char *branch1, *branch2;
 +		const char *ren1_src, *ren1_dst;
 +
 +		if (i >= a_renames->nr) {
 +			compare = 1;
 +			ren2 = b_renames->items[j++].util;
 +		} else if (j >= b_renames->nr) {
 +			compare = -1;
 +			ren1 = a_renames->items[i++].util;
 +		} else {
 +			compare = strcmp(a_renames->items[i].string,
 +					b_renames->items[j].string);
 +			if (compare <= 0)
 +				ren1 = a_renames->items[i++].util;
 +			if (compare >= 0)
 +				ren2 = b_renames->items[j++].util;
 +		}
 +
 +		/* TODO: refactor, so that 1/2 are not needed */
 +		if (ren1) {
 +			renames1 = a_renames;
 +			renames2 = b_renames;
 +			renames2Dst = &b_by_dst;
 +			branch1 = o->branch1;
 +			branch2 = o->branch2;
 +		} else {
 +			struct rename *tmp;
 +			renames1 = b_renames;
 +			renames2 = a_renames;
 +			renames2Dst = &a_by_dst;
 +			branch1 = o->branch2;
 +			branch2 = o->branch1;
 +			tmp = ren2;
 +			ren2 = ren1;
 +			ren1 = tmp;
 +		}
 +		src = ren1->pair->one->path;
 +
 +		ren1->dst_entry->processed = 1;
 +		ren1->src_entry->processed = 1;
 +
 +		if (ren1->processed)
 +			continue;
 +		ren1->processed = 1;
 +
 +		ren1_src = ren1->pair->one->path;
 +		ren1_dst = ren1->pair->two->path;
 +
 +		if (ren2) {
 +			const char *ren2_src = ren2->pair->one->path;
 +			const char *ren2_dst = ren2->pair->two->path;
 +			/* Renamed in 1 and renamed in 2 */
 +			if (strcmp(ren1_src, ren2_src) != 0)
 +				die("ren1.src != ren2.src");
 +			ren2->dst_entry->processed = 1;
 +			ren2->processed = 1;
 +			if (strcmp(ren1_dst, ren2_dst) != 0) {
 +				clean_merge = 0;
 +				output(o, 1, "CONFLICT (rename/rename): "
 +				       "Rename \"%s\"->\"%s\" in branch \"%s\" "
 +				       "rename \"%s\"->\"%s\" in \"%s\"%s",
 +				       src, ren1_dst, branch1,
 +				       src, ren2_dst, branch2,
 +				       o->call_depth ? " (left unresolved)": "");
 +				if (o->call_depth) {
 +					remove_file_from_cache(src);
 +					update_file(o, 0, ren1->pair->one->sha1,
 +						    ren1->pair->one->mode, src);
 +				}
 +				conflict_rename_rename(o, ren1, branch1, ren2, branch2);
 +			} else {
 +				struct merge_file_info mfi;
 +				remove_file(o, 1, ren1_src, 1);
 +				mfi = merge_file(o,
 +						 ren1->pair->one,
 +						 ren1->pair->two,
 +						 ren2->pair->two,
 +						 branch1,
 +						 branch2);
 +				if (mfi.merge || !mfi.clean)
 +					output(o, 1, "Renaming %s->%s", src, ren1_dst);
 +
 +				if (mfi.merge)
 +					output(o, 2, "Auto-merging %s", ren1_dst);
 +
 +				if (!mfi.clean) {
 +					output(o, 1, "CONFLICT (content): merge conflict in %s",
 +					       ren1_dst);
 +					clean_merge = 0;
 +
 +					if (!o->call_depth)
 +						update_stages(ren1_dst,
 +							      ren1->pair->one,
 +							      ren1->pair->two,
 +							      ren2->pair->two,
 +							      1 /* clear */);
 +				}
 +				update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 +			}
 +		} else {
 +			/* Renamed in 1, maybe changed in 2 */
 +			struct string_list_item *item;
 +			/* we only use sha1 and mode of these */
 +			struct diff_filespec src_other, dst_other;
 +			int try_merge, stage = a_renames == renames1 ? 3: 2;
 +
 +			remove_file(o, 1, ren1_src, o->call_depth || stage == 3);
 +
 +			hashcpy(src_other.sha1, ren1->src_entry->stages[stage].sha);
 +			src_other.mode = ren1->src_entry->stages[stage].mode;
 +			hashcpy(dst_other.sha1, ren1->dst_entry->stages[stage].sha);
 +			dst_other.mode = ren1->dst_entry->stages[stage].mode;
 +
 +			try_merge = 0;
 +
 +			if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 +				clean_merge = 0;
 +				output(o, 1, "CONFLICT (rename/directory): Rename %s->%s in %s "
 +				       " directory %s added in %s",
 +				       ren1_src, ren1_dst, branch1,
 +				       ren1_dst, branch2);
 +				conflict_rename_dir(o, ren1, branch1);
 +			} else if (sha_eq(src_other.sha1, null_sha1)) {
 +				clean_merge = 0;
 +				output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 +				       "and deleted in %s",
 +				       ren1_src, ren1_dst, branch1,
 +				       branch2);
 +				update_file(o, 0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 +			} else if (!sha_eq(dst_other.sha1, null_sha1)) {
 +				const char *new_path;
 +				clean_merge = 0;
 +				try_merge = 1;
 +				output(o, 1, "CONFLICT (rename/add): Rename %s->%s in %s. "
 +				       "%s added in %s",
 +				       ren1_src, ren1_dst, branch1,
 +				       ren1_dst, branch2);
 +				new_path = unique_path(o, ren1_dst, branch2);
 +				output(o, 1, "Adding as %s instead", new_path);
 +				update_file(o, 0, dst_other.sha1, dst_other.mode, new_path);
 +			} else if ((item = string_list_lookup(ren1_dst, renames2Dst))) {
 +				ren2 = item->util;
 +				clean_merge = 0;
 +				ren2->processed = 1;
 +				output(o, 1, "CONFLICT (rename/rename): "
 +				       "Rename %s->%s in %s. "
 +				       "Rename %s->%s in %s",
 +				       ren1_src, ren1_dst, branch1,
 +				       ren2->pair->one->path, ren2->pair->two->path, branch2);
 +				conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
 +			} else
 +				try_merge = 1;
 +
 +			if (try_merge) {
 +				struct diff_filespec *one, *a, *b;
 +				struct merge_file_info mfi;
 +				src_other.path = (char *)ren1_src;
 +
 +				one = ren1->pair->one;
 +				if (a_renames == renames1) {
 +					a = ren1->pair->two;
 +					b = &src_other;
 +				} else {
 +					b = ren1->pair->two;
 +					a = &src_other;
 +				}
 +				mfi = merge_file(o, one, a, b,
 +						o->branch1, o->branch2);
 +
 +				if (mfi.clean &&
 +				    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
 +				    mfi.mode == ren1->pair->two->mode)
 +					/*
 +					 * This messaged is part of
 +					 * t6022 test. If you change
 +					 * it update the test too.
 +					 */
 +					output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
 +				else {
 +					if (mfi.merge || !mfi.clean)
 +						output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
 +					if (mfi.merge)
 +						output(o, 2, "Auto-merging %s", ren1_dst);
 +					if (!mfi.clean) {
 +						output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
 +						       ren1_dst);
 +						clean_merge = 0;
 +
 +						if (!o->call_depth)
 +							update_stages(ren1_dst,
 +								      one, a, b, 1);
 +					}
 +					update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 +				}
 +			}
 +		}
 +	}
 +	string_list_clear(&a_by_dst, 0);
 +	string_list_clear(&b_by_dst, 0);
 +
 +	return clean_merge;
 +}
 +
 +static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
 +{
 +	return (is_null_sha1(sha) || mode == 0) ? NULL: (unsigned char *)sha;
 +}
 +
 +/* Per entry merge function */
 +static int process_entry(struct merge_options *o,
 +			 const char *path, struct stage_data *entry)
 +{
 +	/*
 +	printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
 +	print_index_entry("\tpath: ", entry);
 +	*/
 +	int clean_merge = 1;
 +	unsigned o_mode = entry->stages[1].mode;
 +	unsigned a_mode = entry->stages[2].mode;
 +	unsigned b_mode = entry->stages[3].mode;
 +	unsigned char *o_sha = stage_sha(entry->stages[1].sha, o_mode);
 +	unsigned char *a_sha = stage_sha(entry->stages[2].sha, a_mode);
 +	unsigned char *b_sha = stage_sha(entry->stages[3].sha, b_mode);
 +
 +	if (o_sha && (!a_sha || !b_sha)) {
 +		/* Case A: Deleted in one */
 +		if ((!a_sha && !b_sha) ||
 +		    (sha_eq(a_sha, o_sha) && !b_sha) ||
 +		    (!a_sha && sha_eq(b_sha, o_sha))) {
 +			/* Deleted in both or deleted in one and
 +			 * unchanged in the other */
 +			if (a_sha)
 +				output(o, 2, "Removing %s", path);
 +			/* do not touch working file if it did not exist */
 +			remove_file(o, 1, path, !a_sha);
 +		} else {
 +			/* Deleted in one and changed in the other */
 +			clean_merge = 0;
 +			if (!a_sha) {
 +				output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
 +				       "and modified in %s. Version %s of %s left in tree.",
 +				       path, o->branch1,
 +				       o->branch2, o->branch2, path);
 +				update_file(o, 0, b_sha, b_mode, path);
 +			} else {
 +				output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
 +				       "and modified in %s. Version %s of %s left in tree.",
 +				       path, o->branch2,
 +				       o->branch1, o->branch1, path);
 +				update_file(o, 0, a_sha, a_mode, path);
 +			}
 +		}
 +
 +	} else if ((!o_sha && a_sha && !b_sha) ||
 +		   (!o_sha && !a_sha && b_sha)) {
 +		/* Case B: Added in one. */
 +		const char *add_branch;
 +		const char *other_branch;
 +		unsigned mode;
 +		const unsigned char *sha;
 +		const char *conf;
 +
 +		if (a_sha) {
 +			add_branch = o->branch1;
 +			other_branch = o->branch2;
 +			mode = a_mode;
 +			sha = a_sha;
 +			conf = "file/directory";
 +		} else {
 +			add_branch = o->branch2;
 +			other_branch = o->branch1;
 +			mode = b_mode;
 +			sha = b_sha;
 +			conf = "directory/file";
 +		}
 +		if (string_list_has_string(&o->current_directory_set, path)) {
 +			const char *new_path = unique_path(o, path, add_branch);
 +			clean_merge = 0;
 +			output(o, 1, "CONFLICT (%s): There is a directory with name %s in %s. "
 +			       "Adding %s as %s",
 +			       conf, path, other_branch, path, new_path);
 +			remove_file(o, 0, path, 0);
 +			update_file(o, 0, sha, mode, new_path);
 +		} else {
 +			output(o, 2, "Adding %s", path);
 +			update_file(o, 1, sha, mode, path);
 +		}
 +	} else if (a_sha && b_sha) {
 +		/* Case C: Added in both (check for same permissions) and */
 +		/* case D: Modified in both, but differently. */
 +		const char *reason = "content";
 +		struct merge_file_info mfi;
 +		struct diff_filespec one, a, b;
 +
 +		if (!o_sha) {
 +			reason = "add/add";
 +			o_sha = (unsigned char *)null_sha1;
 +		}
 +		output(o, 2, "Auto-merging %s", path);
 +		one.path = a.path = b.path = (char *)path;
 +		hashcpy(one.sha1, o_sha);
 +		one.mode = o_mode;
 +		hashcpy(a.sha1, a_sha);
 +		a.mode = a_mode;
 +		hashcpy(b.sha1, b_sha);
 +		b.mode = b_mode;
 +
 +		mfi = merge_file(o, &one, &a, &b,
 +				 o->branch1, o->branch2);
 +
 +		clean_merge = mfi.clean;
 +		if (mfi.clean)
 +			update_file(o, 1, mfi.sha, mfi.mode, path);
 +		else if (S_ISGITLINK(mfi.mode))
 +			output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
 +			       "- needs %s", path, sha1_to_hex(b.sha1));
 +		else {
 +			output(o, 1, "CONFLICT (%s): Merge conflict in %s",
 +					reason, path);
 +
 +			if (o->call_depth)
 +				update_file(o, 0, mfi.sha, mfi.mode, path);
 +			else
 +				update_file_flags(o, mfi.sha, mfi.mode, path,
 +					      0 /* update_cache */, 1 /* update_working_directory */);
 +		}
 +	} else if (!o_sha && !a_sha && !b_sha) {
 +		/*
 +		 * this entry was deleted altogether. a_mode == 0 means
 +		 * we had that path and want to actively remove it.
 +		 */
 +		remove_file(o, 1, path, !a_mode);
 +	} else
 +		die("Fatal merge failure, shouldn't happen.");
 +
 +	return clean_merge;
 +}
 +
 +int merge_trees(struct merge_options *o,
 +		struct tree *head,
 +		struct tree *merge,
 +		struct tree *common,
 +		struct tree **result)
 +{
 +	int code, clean;
 +
 +	if (o->subtree_merge) {
 +		merge = shift_tree_object(head, merge);
 +		common = shift_tree_object(head, common);
 +	}
 +
 +	if (sha_eq(common->object.sha1, merge->object.sha1)) {
 +		output(o, 0, "Already uptodate!");
 +		*result = head;
 +		return 1;
 +	}
 +
 +	code = git_merge_trees(o->call_depth, common, head, merge);
 +
 +	if (code != 0)
 +		die("merging of trees %s and %s failed",
 +		    sha1_to_hex(head->object.sha1),
 +		    sha1_to_hex(merge->object.sha1));
 +
 +	if (unmerged_cache()) {
 +		struct string_list *entries, *re_head, *re_merge;
 +		int i;
 +		string_list_clear(&o->current_file_set, 1);
 +		string_list_clear(&o->current_directory_set, 1);
 +		get_files_dirs(o, head);
 +		get_files_dirs(o, merge);
 +
 +		entries = get_unmerged();
 +		re_head  = get_renames(o, head, common, head, merge, entries);
 +		re_merge = get_renames(o, merge, common, head, merge, entries);
 +		clean = process_renames(o, re_head, re_merge);
 +		for (i = 0; i < entries->nr; i++) {
 +			const char *path = entries->items[i].string;
 +			struct stage_data *e = entries->items[i].util;
 +			if (!e->processed
 +				&& !process_entry(o, path, e))
 +				clean = 0;
 +		}
 +
 +		string_list_clear(re_merge, 0);
 +		string_list_clear(re_head, 0);
 +		string_list_clear(entries, 1);
 +
 +	}
 +	else
 +		clean = 1;
 +
 +	if (o->call_depth)
 +		*result = write_tree_from_memory(o);
 +
 +	return clean;
 +}
 +
 +static struct commit_list *reverse_commit_list(struct commit_list *list)
 +{
 +	struct commit_list *next = NULL, *current, *backup;
 +	for (current = list; current; current = backup) {
 +		backup = current->next;
 +		current->next = next;
 +		next = current;
 +	}
 +	return next;
 +}
 +
 +/*
 + * Merge the commits h1 and h2, return the resulting virtual
 + * commit object and a flag indicating the cleanness of the merge.
 + */
 +int merge_recursive(struct merge_options *o,
 +		    struct commit *h1,
 +		    struct commit *h2,
 +		    struct commit_list *ca,
 +		    struct commit **result)
 +{
 +	struct commit_list *iter;
 +	struct commit *merged_common_ancestors;
 +	struct tree *mrtree = mrtree;
 +	int clean;
 +
 +	if (show(o, 4)) {
 +		output(o, 4, "Merging:");
 +		output_commit_title(o, h1);
 +		output_commit_title(o, h2);
 +	}
 +
 +	if (!ca) {
 +		ca = get_merge_bases(h1, h2, 1);
 +		ca = reverse_commit_list(ca);
 +	}
 +
 +	if (show(o, 5)) {
 +		output(o, 5, "found %u common ancestor(s):", commit_list_count(ca));
 +		for (iter = ca; iter; iter = iter->next)
 +			output_commit_title(o, iter->item);
 +	}
 +
 +	merged_common_ancestors = pop_commit(&ca);
 +	if (merged_common_ancestors == NULL) {
 +		/* if there is no common ancestor, make an empty tree */
 +		struct tree *tree = xcalloc(1, sizeof(struct tree));
 +
 +		tree->object.parsed = 1;
 +		tree->object.type = OBJ_TREE;
 +		pretend_sha1_file(NULL, 0, OBJ_TREE, tree->object.sha1);
 +		merged_common_ancestors = make_virtual_commit(tree, "ancestor");
 +	}
 +
 +	for (iter = ca; iter; iter = iter->next) {
 +		const char *saved_b1, *saved_b2;
 +		o->call_depth++;
 +		/*
 +		 * When the merge fails, the result contains files
 +		 * with conflict markers. The cleanness flag is
 +		 * ignored, it was never actually used, as result of
 +		 * merge_trees has always overwritten it: the committed
 +		 * "conflicts" were already resolved.
 +		 */
 +		discard_cache();
 +		saved_b1 = o->branch1;
 +		saved_b2 = o->branch2;
 +		o->branch1 = "Temporary merge branch 1";
 +		o->branch2 = "Temporary merge branch 2";
 +		merge_recursive(o, merged_common_ancestors, iter->item,
 +				NULL, &merged_common_ancestors);
 +		o->branch1 = saved_b1;
 +		o->branch2 = saved_b2;
 +		o->call_depth--;
 +
 +		if (!merged_common_ancestors)
 +			die("merge returned no commit");
 +	}
 +
 +	discard_cache();
 +	if (!o->call_depth)
 +		read_cache();
 +
 +	clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
 +			    &mrtree);
 +
 +	if (o->call_depth) {
 +		*result = make_virtual_commit(mrtree, "merged tree");
 +		commit_list_insert(h1, &(*result)->parents);
 +		commit_list_insert(h2, &(*result)->parents->next);
 +	}
 +	flush_output(o);
 +	return clean;
 +}
 +
 +static struct commit *get_ref(const unsigned char *sha1, const char *name)
 +{
 +	struct object *object;
 +
 +	object = deref_tag(parse_object(sha1), name, strlen(name));
 +	if (!object)
 +		return NULL;
 +	if (object->type == OBJ_TREE)
 +		return make_virtual_commit((struct tree*)object, name);
 +	if (object->type != OBJ_COMMIT)
 +		return NULL;
 +	if (parse_commit((struct commit *)object))
 +		return NULL;
 +	return (struct commit *)object;
 +}
 +
 +int merge_recursive_generic(struct merge_options *o,
 +			    const unsigned char *head,
 +			    const unsigned char *merge,
 +			    int num_base_list,
 +			    const unsigned char **base_list,
 +			    struct commit **result)
 +{
 +	int clean, index_fd;
 +	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 +	struct commit *head_commit = get_ref(head, o->branch1);
 +	struct commit *next_commit = get_ref(merge, o->branch2);
 +	struct commit_list *ca = NULL;
 +
 +	if (base_list) {
 +		int i;
 +		for (i = 0; i < num_base_list; ++i) {
 +			struct commit *base;
 +			if (!(base = get_ref(base_list[i], sha1_to_hex(base_list[i]))))
 +				return error("Could not parse object '%s'",
 +					sha1_to_hex(base_list[i]));
 +			commit_list_insert(base, &ca);
 +		}
 +	}
 +
 +	index_fd = hold_locked_index(lock, 1);
 +	clean = merge_recursive(o, head_commit, next_commit, ca,
 +			result);
 +	if (active_cache_changed &&
 +			(write_cache(index_fd, active_cache, active_nr) ||
 +			 commit_locked_index(lock)))
 +		return error("Unable to write index.");
 +
 +	return clean ? 0 : 1;
 +}
 +
 +static int merge_recursive_config(const char *var, const char *value, void *cb)
 +{
 +	struct merge_options *o = cb;
 +	if (!strcasecmp(var, "merge.verbosity")) {
 +		o->verbosity = git_config_int(var, value);
 +		return 0;
 +	}
 +	if (!strcasecmp(var, "diff.renamelimit")) {
 +		o->diff_rename_limit = git_config_int(var, value);
 +		return 0;
 +	}
 +	if (!strcasecmp(var, "merge.renamelimit")) {
 +		o->merge_rename_limit = git_config_int(var, value);
 +		return 0;
 +	}
 +	return git_xmerge_config(var, value, cb);
 +}
 +
 +void init_merge_options(struct merge_options *o)
 +{
 +	memset(o, 0, sizeof(struct merge_options));
 +	o->verbosity = 2;
 +	o->buffer_output = 1;
 +	o->diff_rename_limit = -1;
 +	o->merge_rename_limit = -1;
 +	git_config(merge_recursive_config, o);
 +	if (getenv("GIT_MERGE_VERBOSITY"))
 +		o->verbosity =
 +			strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
 +	if (o->verbosity >= 5)
 +		o->buffer_output = 0;
 +	strbuf_init(&o->obuf, 0);
 +	memset(&o->current_file_set, 0, sizeof(struct string_list));
 +	o->current_file_set.strdup_strings = 1;
 +	memset(&o->current_directory_set, 0, sizeof(struct string_list));
 +	o->current_directory_set.strdup_strings = 1;
 +}