X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=merge-recursive.c;h=245232a4083bbd8cdadf3b32a0a20db559941f8a;hb=a324fc45e4d04e3b879cd2d9a603d73ca696b775;hp=55ef76f5a5f855475f796dfda39fa3417179be8b;hpb=b23b27eb5dc950081d4f76ae84f10168c4d149bd;p=git.git

diff --git a/merge-recursive.c b/merge-recursive.c
index 55ef76f5a..245232a40 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -7,18 +7,19 @@
 #include "cache-tree.h"
 #include "commit.h"
 #include "blob.h"
+#include "builtin.h"
 #include "tree-walk.h"
 #include "diff.h"
 #include "diffcore.h"
-#include "run-command.h"
 #include "tag.h"
 #include "unpack-trees.h"
-#include "path-list.h"
+#include "string-list.h"
 #include "xdiff-interface.h"
+#include "ll-merge.h"
 #include "interpolate.h"
 #include "attr.h"
-
-static int subtree_merge;
+#include "merge-recursive.h"
+#include "dir.h"
 
 static struct tree *shift_tree_object(struct tree *one, struct tree *two)
 {
@@ -35,26 +36,14 @@ static struct tree *shift_tree_object(struct tree *one, struct tree *two)
 }
 
 /*
- * A virtual commit has
- * - (const char *)commit->util set to the name, and
- * - *(int *)commit->object.sha1 set to the virtual id.
+ * A virtual commit has (const char *)commit->util set to the name.
  */
 
-static unsigned commit_list_count(const struct commit_list *l)
-{
-	unsigned c = 0;
-	for (; l; l = l->next )
-		c++;
-	return c;
-}
-
-static struct commit *make_virtual_commit(struct tree *tree, const char *comment)
+struct commit *make_virtual_commit(struct tree *tree, const char *comment)
 {
 	struct commit *commit = xcalloc(1, sizeof(struct commit));
-	static unsigned virtual_id = 1;
 	commit->tree = tree;
 	commit->util = (void*)comment;
-	*(int*)commit->object.sha1 = virtual_id++;
 	/* avoid warnings */
 	commit->object.parsed = 1;
 	return commit;
@@ -85,66 +74,57 @@ struct stage_data
 	unsigned processed:1;
 };
 
-static struct path_list current_file_set = {NULL, 0, 0, 1};
-static struct path_list current_directory_set = {NULL, 0, 0, 1};
-
-static int call_depth = 0;
-static int verbosity = 2;
-static int rename_limit = -1;
-static int buffer_output = 1;
-static struct strbuf obuf = STRBUF_INIT;
-
-static int show(int v)
+static int show(struct merge_options *o, int v)
 {
-	return (!call_depth && verbosity >= v) || verbosity >= 5;
+	return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
 }
 
-static void flush_output(void)
+static void flush_output(struct merge_options *o)
 {
-	if (obuf.len) {
-		fputs(obuf.buf, stdout);
-		strbuf_reset(&obuf);
+	if (o->obuf.len) {
+		fputs(o->obuf.buf, stdout);
+		strbuf_reset(&o->obuf);
 	}
 }
 
-static void output(int v, const char *fmt, ...)
+static void output(struct merge_options *o, int v, const char *fmt, ...)
 {
 	int len;
 	va_list ap;
 
-	if (!show(v))
+	if (!show(o, v))
 		return;
 
-	strbuf_grow(&obuf, call_depth * 2 + 2);
-	memset(obuf.buf + obuf.len, ' ', call_depth * 2);
-	strbuf_setlen(&obuf, obuf.len + call_depth * 2);
+	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(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
+	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(&obuf)) {
-		strbuf_grow(&obuf, len + 2);
+	if (len >= strbuf_avail(&o->obuf)) {
+		strbuf_grow(&o->obuf, len + 2);
 		va_start(ap, fmt);
-		len = vsnprintf(obuf.buf + obuf.len, strbuf_avail(&obuf), fmt, ap);
+		len = vsnprintf(o->obuf.buf + o->obuf.len, strbuf_avail(&o->obuf), fmt, ap);
 		va_end(ap);
-		if (len >= strbuf_avail(&obuf)) {
+		if (len >= strbuf_avail(&o->obuf)) {
 			die("this should not happen, your snprintf is broken");
 		}
 	}
-	strbuf_setlen(&obuf, obuf.len + len);
-	strbuf_add(&obuf, "\n", 1);
-	if (!buffer_output)
-		flush_output();
+	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 commit *commit)
+static void output_commit_title(struct merge_options *o, struct commit *commit)
 {
 	int i;
-	flush_output();
-	for (i = call_depth; i--;)
+	flush_output(o);
+	for (i = o->call_depth; i--;)
 		fputs("  ", stdout);
 	if (commit->util)
 		printf("virtual %s\n", (char *)commit->util);
@@ -177,17 +157,6 @@ static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 	return add_cache_entry(ce, options);
 }
 
-/*
- * This is a global variable which is used in a number of places but
- * only written to in the 'merge' function.
- *
- * index_only == 1    => Don't leave any non-stage 0 entries in the cache and
- *                       don't update the working directory.
- *               0    => Leave unmerged entries in the cache and update
- *                       the working directory.
- */
-static int index_only = 0;
-
 static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
 {
 	parse_tree(tree);
@@ -211,6 +180,8 @@ static int git_merge_trees(int index_only,
 	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);
@@ -221,28 +192,17 @@ static int git_merge_trees(int index_only,
 	return rc;
 }
 
-static int unmerged_index(void)
-{
-	int i;
-	for (i = 0; i < active_nr; i++) {
-		struct cache_entry *ce = active_cache[i];
-		if (ce_stage(ce))
-			return 1;
-	}
-	return 0;
-}
-
-static struct tree *git_write_tree(void)
+struct tree *write_tree_from_memory(struct merge_options *o)
 {
 	struct tree *result = NULL;
 
-	if (unmerged_index()) {
+	if (unmerged_cache()) {
 		int i;
-		output(0, "There are unmerged index entries:");
+		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(0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
+				output(o, 0, "%d %.*s", ce_stage(ce), ce_namelen(ce), ce->name);
 		}
 		return NULL;
 	}
@@ -262,29 +222,31 @@ static struct tree *git_write_tree(void)
 
 static int save_files_dirs(const unsigned char *sha1,
 		const char *base, int baselen, const char *path,
-		unsigned int mode, int stage)
+		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))
-		path_list_insert(newpath, &current_directory_set);
+		string_list_insert(newpath, &o->current_directory_set);
 	else
-		path_list_insert(newpath, &current_file_set);
+		string_list_insert(newpath, &o->current_file_set);
 	free(newpath);
 
 	return READ_TREE_RECURSIVE;
 }
 
-static int get_files_dirs(struct tree *tree)
+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) != 0)
+	if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs, o))
 		return 0;
-	n = current_file_set.nr + current_directory_set.nr;
+	n = o->current_file_set.nr + o->current_directory_set.nr;
 	return n;
 }
 
@@ -294,9 +256,9 @@ static int get_files_dirs(struct tree *tree)
  */
 static struct stage_data *insert_stage_data(const char *path,
 		struct tree *o, struct tree *a, struct tree *b,
-		struct path_list *entries)
+		struct string_list *entries)
 {
-	struct path_list_item *item;
+	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);
@@ -304,7 +266,7 @@ static struct stage_data *insert_stage_data(const char *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 = path_list_insert(path, entries);
+	item = string_list_insert(path, entries);
 	item->util = e;
 	return e;
 }
@@ -313,23 +275,23 @@ static struct stage_data *insert_stage_data(const char *path,
  * 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 path_list *get_unmerged(void)
+static struct string_list *get_unmerged(void)
 {
-	struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
+	struct string_list *unmerged = xcalloc(1, sizeof(struct string_list));
 	int i;
 
-	unmerged->strdup_paths = 1;
+	unmerged->strdup_strings = 1;
 
 	for (i = 0; i < active_nr; i++) {
-		struct path_list_item *item;
+		struct string_list_item *item;
 		struct stage_data *e;
 		struct cache_entry *ce = active_cache[i];
 		if (!ce_stage(ce))
 			continue;
 
-		item = path_list_lookup(ce->name, unmerged);
+		item = string_list_lookup(ce->name, unmerged);
 		if (!item) {
-			item = path_list_insert(ce->name, unmerged);
+			item = string_list_insert(ce->name, unmerged);
 			item->util = xcalloc(1, sizeof(struct stage_data));
 		}
 		e = item->util;
@@ -354,28 +316,32 @@ struct rename
  * '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 path_list *get_renames(struct tree *tree,
-					struct tree *o_tree,
-					struct tree *a_tree,
-					struct tree *b_tree,
-					struct path_list *entries)
+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 path_list *renames;
+	struct string_list *renames;
 	struct diff_options opts;
 
-	renames = xcalloc(1, sizeof(struct path_list));
+	renames = xcalloc(1, sizeof(struct string_list));
 	diff_setup(&opts);
 	DIFF_OPT_SET(&opts, RECURSIVE);
 	opts.detect_rename = DIFF_DETECT_RENAME;
-	opts.rename_limit = rename_limit;
+	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 path_list_item *item;
+		struct string_list_item *item;
 		struct rename *re;
 		struct diff_filepair *pair = diff_queued_diff.queue[i];
 		if (pair->status != 'R') {
@@ -385,20 +351,20 @@ static struct path_list *get_renames(struct tree *tree,
 		re = xmalloc(sizeof(*re));
 		re->processed = 0;
 		re->pair = pair;
-		item = path_list_lookup(re->pair->one->path, entries);
+		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 = path_list_lookup(re->pair->two->path, entries);
+		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 = path_list_insert(pair->one->path, renames);
+		item = string_list_insert(pair->one->path, renames);
 		item->util = re;
 	}
 	opts.output_format = DIFF_FORMAT_NO_OUTPUT;
@@ -427,43 +393,24 @@ static int update_stages(const char *path, struct diff_filespec *o,
 	return 0;
 }
 
-static int remove_path(const char *name)
+static int remove_file(struct merge_options *o, int clean,
+		       const char *path, int no_wd)
 {
-	int ret;
-	char *slash, *dirs;
-
-	ret = unlink(name);
-	if (ret)
-		return ret;
-	dirs = xstrdup(name);
-	while ((slash = strrchr(name, '/'))) {
-		*slash = '\0';
-		if (rmdir(name) != 0)
-			break;
-	}
-	free(dirs);
-	return ret;
-}
-
-static int remove_file(int clean, const char *path, int no_wd)
-{
-	int update_cache = index_only || clean;
-	int update_working_directory = !index_only && !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) {
-		unlink(path);
-		if (errno != ENOENT || errno != EISDIR)
+		if (remove_path(path) && errno != ENOENT)
 			return -1;
-		remove_path(path);
 	}
 	return 0;
 }
 
-static char *unique_path(const char *path, const char *branch)
+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;
@@ -475,24 +422,15 @@ static char *unique_path(const char *path, const char *branch)
 	for (; *p; ++p)
 		if ('/' == *p)
 			*p = '_';
-	while (path_list_has_path(&current_file_set, newpath) ||
-	       path_list_has_path(&current_directory_set, newpath) ||
+	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++);
 
-	path_list_insert(newpath, &current_file_set);
+	string_list_insert(newpath, &o->current_file_set);
 	return newpath;
 }
 
-static int mkdir_p(const char *path, unsigned long mode)
-{
-	/* path points to cache entries, so xstrdup before messing with it */
-	char *buf = xstrdup(path);
-	int result = safe_create_leading_directories(buf);
-	free(buf);
-	return result;
-}
-
 static void flush_buffer(int fd, const char *buf, unsigned long size)
 {
 	while (size > 0) {
@@ -515,7 +453,7 @@ static int make_room_for_path(const char *path)
 	int status;
 	const char *msg = "failed to create path '%s'%s";
 
-	status = mkdir_p(path, 0777);
+	status = safe_create_leading_directories_const(path);
 	if (status) {
 		if (status == -3) {
 			/* something else exists */
@@ -535,13 +473,14 @@ static int make_room_for_path(const char *path)
 	return error(msg, path, ": perhaps a D/F conflict?");
 }
 
-static void update_file_flags(const unsigned char *sha,
+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 (index_only)
+	if (o->call_depth)
 		update_wd = 0;
 
 	if (update_wd) {
@@ -558,9 +497,18 @@ static void update_file_flags(const unsigned char *sha,
 			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))) {
@@ -576,25 +524,27 @@ static void update_file_flags(const unsigned char *sha,
 			close(fd);
 		} else if (S_ISLNK(mode)) {
 			char *lnk = xmemdupz(buf, size);
-			mkdir_p(path, 0777);
+			safe_create_leading_directories_const(path);
 			unlink(path);
 			symlink(lnk, path);
 			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(int clean,
+static void update_file(struct merge_options *o,
+			int clean,
 			const unsigned char *sha,
 			unsigned mode,
 			const char *path)
 {
-	update_file_flags(sha, mode, path, index_only || clean, !index_only);
+	update_file_flags(o, sha, mode, path, o->call_depth || clean, !o->call_depth);
 }
 
 /* Low level file merging, update and removal */
@@ -624,380 +574,28 @@ static void fill_mm(const unsigned char *sha1, mmfile_t *mm)
 	mm->size = size;
 }
 
-/*
- * Customizable low-level merge drivers support.
- */
-
-struct ll_merge_driver;
-typedef int (*ll_merge_fn)(const struct ll_merge_driver *,
-			   const char *path,
-			   mmfile_t *orig,
-			   mmfile_t *src1, const char *name1,
-			   mmfile_t *src2, const char *name2,
-			   mmbuffer_t *result);
-
-struct ll_merge_driver {
-	const char *name;
-	const char *description;
-	ll_merge_fn fn;
-	const char *recursive;
-	struct ll_merge_driver *next;
-	char *cmdline;
-};
-
-/*
- * Built-in low-levels
- */
-static int ll_binary_merge(const struct ll_merge_driver *drv_unused,
-			   const char *path_unused,
-			   mmfile_t *orig,
-			   mmfile_t *src1, const char *name1,
-			   mmfile_t *src2, const char *name2,
-			   mmbuffer_t *result)
-{
-	/*
-	 * The tentative merge result is "ours" for the final round,
-	 * or common ancestor for an internal merge.  Still return
-	 * "conflicted merge" status.
-	 */
-	mmfile_t *stolen = index_only ? orig : src1;
-
-	result->ptr = stolen->ptr;
-	result->size = stolen->size;
-	stolen->ptr = NULL;
-	return 1;
-}
-
-static int ll_xdl_merge(const struct ll_merge_driver *drv_unused,
-			const char *path_unused,
-			mmfile_t *orig,
-			mmfile_t *src1, const char *name1,
-			mmfile_t *src2, const char *name2,
-			mmbuffer_t *result)
-{
-	xpparam_t xpp;
-
-	if (buffer_is_binary(orig->ptr, orig->size) ||
-	    buffer_is_binary(src1->ptr, src1->size) ||
-	    buffer_is_binary(src2->ptr, src2->size)) {
-		warning("Cannot merge binary files: %s vs. %s\n",
-			name1, name2);
-		return ll_binary_merge(drv_unused, path_unused,
-				       orig, src1, name1,
-				       src2, name2,
-				       result);
-	}
-
-	memset(&xpp, 0, sizeof(xpp));
-	return xdl_merge(orig,
-			 src1, name1,
-			 src2, name2,
-			 &xpp, XDL_MERGE_ZEALOUS,
-			 result);
-}
-
-static int ll_union_merge(const struct ll_merge_driver *drv_unused,
-			  const char *path_unused,
-			  mmfile_t *orig,
-			  mmfile_t *src1, const char *name1,
-			  mmfile_t *src2, const char *name2,
-			  mmbuffer_t *result)
-{
-	char *src, *dst;
-	long size;
-	const int marker_size = 7;
-
-	int status = ll_xdl_merge(drv_unused, path_unused,
-				  orig, src1, NULL, src2, NULL, result);
-	if (status <= 0)
-		return status;
-	size = result->size;
-	src = dst = result->ptr;
-	while (size) {
-		char ch;
-		if ((marker_size < size) &&
-		    (*src == '<' || *src == '=' || *src == '>')) {
-			int i;
-			ch = *src;
-			for (i = 0; i < marker_size; i++)
-				if (src[i] != ch)
-					goto not_a_marker;
-			if (src[marker_size] != '\n')
-				goto not_a_marker;
-			src += marker_size + 1;
-			size -= marker_size + 1;
-			continue;
-		}
-	not_a_marker:
-		do {
-			ch = *src++;
-			*dst++ = ch;
-			size--;
-		} while (ch != '\n' && size);
-	}
-	result->size = dst - result->ptr;
-	return 0;
-}
-
-#define LL_BINARY_MERGE 0
-#define LL_TEXT_MERGE 1
-#define LL_UNION_MERGE 2
-static struct ll_merge_driver ll_merge_drv[] = {
-	{ "binary", "built-in binary merge", ll_binary_merge },
-	{ "text", "built-in 3-way text merge", ll_xdl_merge },
-	{ "union", "built-in union merge", ll_union_merge },
-};
-
-static void create_temp(mmfile_t *src, char *path)
-{
-	int fd;
-
-	strcpy(path, ".merge_file_XXXXXX");
-	fd = xmkstemp(path);
-	if (write_in_full(fd, src->ptr, src->size) != src->size)
-		die("unable to write temp-file");
-	close(fd);
-}
-
-/*
- * User defined low-level merge driver support.
- */
-static int ll_ext_merge(const struct ll_merge_driver *fn,
-			const char *path,
-			mmfile_t *orig,
-			mmfile_t *src1, const char *name1,
-			mmfile_t *src2, const char *name2,
-			mmbuffer_t *result)
-{
-	char temp[3][50];
-	char cmdbuf[2048];
-	struct interp table[] = {
-		{ "%O" },
-		{ "%A" },
-		{ "%B" },
-	};
-	struct child_process child;
-	const char *args[20];
-	int status, fd, i;
-	struct stat st;
-
-	if (fn->cmdline == NULL)
-		die("custom merge driver %s lacks command line.", fn->name);
-
-	result->ptr = NULL;
-	result->size = 0;
-	create_temp(orig, temp[0]);
-	create_temp(src1, temp[1]);
-	create_temp(src2, temp[2]);
-
-	interp_set_entry(table, 0, temp[0]);
-	interp_set_entry(table, 1, temp[1]);
-	interp_set_entry(table, 2, temp[2]);
-
-	output(1, "merging %s using %s", path,
-	       fn->description ? fn->description : fn->name);
-
-	interpolate(cmdbuf, sizeof(cmdbuf), fn->cmdline, table, 3);
-
-	memset(&child, 0, sizeof(child));
-	child.argv = args;
-	args[0] = "sh";
-	args[1] = "-c";
-	args[2] = cmdbuf;
-	args[3] = NULL;
-
-	status = run_command(&child);
-	if (status < -ERR_RUN_COMMAND_FORK)
-		; /* failure in run-command */
-	else
-		status = -status;
-	fd = open(temp[1], O_RDONLY);
-	if (fd < 0)
-		goto bad;
-	if (fstat(fd, &st))
-		goto close_bad;
-	result->size = st.st_size;
-	result->ptr = xmalloc(result->size + 1);
-	if (read_in_full(fd, result->ptr, result->size) != result->size) {
-		free(result->ptr);
-		result->ptr = NULL;
-		result->size = 0;
-	}
- close_bad:
-	close(fd);
- bad:
-	for (i = 0; i < 3; i++)
-		unlink(temp[i]);
-	return status;
-}
-
-/*
- * merge.default and merge.driver configuration items
- */
-static struct ll_merge_driver *ll_user_merge, **ll_user_merge_tail;
-static const char *default_ll_merge;
-
-static int read_merge_config(const char *var, const char *value)
-{
-	struct ll_merge_driver *fn;
-	const char *ep, *name;
-	int namelen;
-
-	if (!strcmp(var, "merge.default")) {
-		if (!value)
-			return config_error_nonbool(var);
-		default_ll_merge = strdup(value);
-		return 0;
-	}
-
-	/*
-	 * We are not interested in anything but "merge.<name>.variable";
-	 * especially, we do not want to look at variables such as
-	 * "merge.summary", "merge.tool", and "merge.verbosity".
-	 */
-	if (prefixcmp(var, "merge.") || (ep = strrchr(var, '.')) == var + 5)
-		return 0;
-
-	/*
-	 * Find existing one as we might be processing merge.<name>.var2
-	 * after seeing merge.<name>.var1.
-	 */
-	name = var + 6;
-	namelen = ep - name;
-	for (fn = ll_user_merge; fn; fn = fn->next)
-		if (!strncmp(fn->name, name, namelen) && !fn->name[namelen])
-			break;
-	if (!fn) {
-		fn = xcalloc(1, sizeof(struct ll_merge_driver));
-		fn->name = xmemdupz(name, namelen);
-		fn->fn = ll_ext_merge;
-		*ll_user_merge_tail = fn;
-		ll_user_merge_tail = &(fn->next);
-	}
-
-	ep++;
-
-	if (!strcmp("name", ep)) {
-		if (!value)
-			return config_error_nonbool(var);
-		fn->description = strdup(value);
-		return 0;
-	}
-
-	if (!strcmp("driver", ep)) {
-		if (!value)
-			return config_error_nonbool(var);
-		/*
-		 * merge.<name>.driver specifies the command line:
-		 *
-		 *	command-line
-		 *
-		 * The command-line will be interpolated with the following
-		 * tokens and is given to the shell:
-		 *
-		 *    %O - temporary file name for the merge base.
-		 *    %A - temporary file name for our version.
-		 *    %B - temporary file name for the other branches' version.
-		 *
-		 * The external merge driver should write the results in the
-		 * file named by %A, and signal that it has done with zero exit
-		 * status.
-		 */
-		fn->cmdline = strdup(value);
-		return 0;
-	}
-
-	if (!strcmp("recursive", ep)) {
-		if (!value)
-			return config_error_nonbool(var);
-		fn->recursive = strdup(value);
-		return 0;
-	}
-
-	return 0;
-}
-
-static void initialize_ll_merge(void)
-{
-	if (ll_user_merge_tail)
-		return;
-	ll_user_merge_tail = &ll_user_merge;
-	git_config(read_merge_config);
-}
-
-static const struct ll_merge_driver *find_ll_merge_driver(const char *merge_attr)
-{
-	struct ll_merge_driver *fn;
-	const char *name;
-	int i;
-
-	initialize_ll_merge();
-
-	if (ATTR_TRUE(merge_attr))
-		return &ll_merge_drv[LL_TEXT_MERGE];
-	else if (ATTR_FALSE(merge_attr))
-		return &ll_merge_drv[LL_BINARY_MERGE];
-	else if (ATTR_UNSET(merge_attr)) {
-		if (!default_ll_merge)
-			return &ll_merge_drv[LL_TEXT_MERGE];
-		else
-			name = default_ll_merge;
-	}
-	else
-		name = merge_attr;
-
-	for (fn = ll_user_merge; fn; fn = fn->next)
-		if (!strcmp(fn->name, name))
-			return fn;
-
-	for (i = 0; i < ARRAY_SIZE(ll_merge_drv); i++)
-		if (!strcmp(ll_merge_drv[i].name, name))
-			return &ll_merge_drv[i];
-
-	/* default to the 3-way */
-	return &ll_merge_drv[LL_TEXT_MERGE];
-}
-
-static const char *git_path_check_merge(const char *path)
-{
-	static struct git_attr_check attr_merge_check;
-
-	if (!attr_merge_check.attr)
-		attr_merge_check.attr = git_attr("merge", 5);
-
-	if (git_checkattr(path, 1, &attr_merge_check))
-		return NULL;
-	return attr_merge_check.value;
-}
-
-static int ll_merge(mmbuffer_t *result_buf,
-		    struct diff_filespec *o,
-		    struct diff_filespec *a,
-		    struct diff_filespec *b,
-		    const char *branch1,
-		    const char *branch2)
+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;
-	const char *ll_driver_name;
-	const struct ll_merge_driver *driver;
 
 	name1 = xstrdup(mkpath("%s:%s", branch1, a->path));
 	name2 = xstrdup(mkpath("%s:%s", branch2, b->path));
 
-	fill_mm(o->sha1, &orig);
+	fill_mm(one->sha1, &orig);
 	fill_mm(a->sha1, &src1);
 	fill_mm(b->sha1, &src2);
 
-	ll_driver_name = git_path_check_merge(a->path);
-	driver = find_ll_merge_driver(ll_driver_name);
-
-	if (index_only && driver->recursive)
-		driver = find_ll_merge_driver(driver->recursive);
-	merge_status = driver->fn(driver, a->path,
-				  &orig, &src1, name1, &src2, name2,
-				  result_buf);
+	merge_status = ll_merge(result_buf, a->path, &orig,
+				&src1, name1, &src2, name2,
+				o->call_depth);
 
 	free(name1);
 	free(name2);
@@ -1007,9 +605,12 @@ static int ll_merge(mmbuffer_t *result_buf,
 	return merge_status;
 }
 
-static struct merge_file_info merge_file(struct diff_filespec *o,
-		struct diff_filespec *a, struct diff_filespec *b,
-		const char *branch1, const char *branch2)
+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;
@@ -1025,21 +626,32 @@ static struct merge_file_info merge_file(struct diff_filespec *o,
 			hashcpy(result.sha, b->sha1);
 		}
 	} else {
-		if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
+		if (!sha_eq(a->sha1, one->sha1) && !sha_eq(b->sha1, one->sha1))
 			result.merge = 1;
 
-		result.mode = a->mode == o->mode ? b->mode: a->mode;
+		/*
+		 * 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, o->sha1))
+		if (sha_eq(a->sha1, b->sha1) || sha_eq(a->sha1, one->sha1))
 			hashcpy(result.sha, b->sha1);
-		else if (sha_eq(b->sha1, o->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 = ll_merge(&result_buf, o, a, b,
-						branch1, branch2);
+			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");
@@ -1067,7 +679,8 @@ static struct merge_file_info merge_file(struct diff_filespec *o,
 	return result;
 }
 
-static void conflict_rename_rename(struct rename *ren1,
+static void conflict_rename_rename(struct merge_options *o,
+				   struct rename *ren1,
 				   const char *branch1,
 				   struct rename *ren2,
 				   const char *branch2)
@@ -1078,26 +691,26 @@ static void conflict_rename_rename(struct rename *ren1,
 	const char *ren2_dst = ren2->pair->two->path;
 	const char *dst_name1 = ren1_dst;
 	const char *dst_name2 = ren2_dst;
-	if (path_list_has_path(&current_directory_set, ren1_dst)) {
-		dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
-		output(1, "%s is a directory in %s added as %s instead",
+	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(0, ren1_dst, 0);
+		remove_file(o, 0, ren1_dst, 0);
 	}
-	if (path_list_has_path(&current_directory_set, ren2_dst)) {
-		dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
-		output(1, "%s is a directory in %s added as %s instead",
+	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(0, ren2_dst, 0);
+		remove_file(o, 0, ren2_dst, 0);
 	}
-	if (index_only) {
+	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(0, ren1->pair->two->sha1, ren1->pair->two->mode, dst_name1);
-		 * update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, dst_name2);
+		 * 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);
@@ -1107,57 +720,58 @@ static void conflict_rename_rename(struct rename *ren1,
 		free(del[delp]);
 }
 
-static void conflict_rename_dir(struct rename *ren1,
+static void conflict_rename_dir(struct merge_options *o,
+				struct rename *ren1,
 				const char *branch1)
 {
-	char *new_path = unique_path(ren1->pair->two->path, branch1);
-	output(1, "Renamed %s to %s instead", ren1->pair->one->path, new_path);
-	remove_file(0, ren1->pair->two->path, 0);
-	update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
+	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 rename *ren1,
+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(ren1->pair->two->path, branch1);
-	char *new_path2 = unique_path(ren2->pair->two->path, branch2);
-	output(1, "Renamed %s to %s and %s to %s instead",
+	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(0, ren1->pair->two->path, 0);
-	update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path1);
-	update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, 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 path_list *a_renames,
-			   struct path_list *b_renames,
-			   const char *a_branch,
-			   const char *b_branch)
+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 path_list a_by_dst = {NULL, 0, 0, 0}, b_by_dst = {NULL, 0, 0, 0};
+	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;
-		path_list_insert(sre->pair->two->path, &a_by_dst)->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;
-		path_list_insert(sre->pair->two->path, &b_by_dst)->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 path_list *renames1, *renames2, *renames2Dst;
+		struct string_list *renames1, *renames2, *renames2Dst;
 		struct rename *ren1 = NULL, *ren2 = NULL;
 		const char *branch1, *branch2;
 		const char *ren1_src, *ren1_dst;
@@ -1169,8 +783,8 @@ static int process_renames(struct path_list *a_renames,
 			compare = -1;
 			ren1 = a_renames->items[i++].util;
 		} else {
-			compare = strcmp(a_renames->items[i].path,
-					b_renames->items[j].path);
+			compare = strcmp(a_renames->items[i].string,
+					b_renames->items[j].string);
 			if (compare <= 0)
 				ren1 = a_renames->items[i++].util;
 			if (compare >= 0)
@@ -1182,15 +796,15 @@ static int process_renames(struct path_list *a_renames,
 			renames1 = a_renames;
 			renames2 = b_renames;
 			renames2Dst = &b_by_dst;
-			branch1 = a_branch;
-			branch2 = b_branch;
+			branch1 = o->branch1;
+			branch2 = o->branch2;
 		} else {
 			struct rename *tmp;
 			renames1 = b_renames;
 			renames2 = a_renames;
 			renames2Dst = &a_by_dst;
-			branch1 = b_branch;
-			branch2 = a_branch;
+			branch1 = o->branch2;
+			branch2 = o->branch1;
 			tmp = ren2;
 			ren2 = ren1;
 			ren1 = tmp;
@@ -1217,54 +831,55 @@ static int process_renames(struct path_list *a_renames,
 			ren2->processed = 1;
 			if (strcmp(ren1_dst, ren2_dst) != 0) {
 				clean_merge = 0;
-				output(1, "CONFLICT (rename/rename): "
+				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,
-				       index_only ? " (left unresolved)": "");
-				if (index_only) {
+				       o->call_depth ? " (left unresolved)": "");
+				if (o->call_depth) {
 					remove_file_from_cache(src);
-					update_file(0, ren1->pair->one->sha1,
+					update_file(o, 0, ren1->pair->one->sha1,
 						    ren1->pair->one->mode, src);
 				}
-				conflict_rename_rename(ren1, branch1, ren2, branch2);
+				conflict_rename_rename(o, ren1, branch1, ren2, branch2);
 			} else {
 				struct merge_file_info mfi;
-				remove_file(1, ren1_src, 1);
-				mfi = merge_file(ren1->pair->one,
+				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(1, "Renamed %s->%s", src, ren1_dst);
+					output(o, 1, "Renaming %s->%s", src, ren1_dst);
 
 				if (mfi.merge)
-					output(2, "Auto-merged %s", ren1_dst);
+					output(o, 2, "Auto-merging %s", ren1_dst);
 
 				if (!mfi.clean) {
-					output(1, "CONFLICT (content): merge conflict in %s",
+					output(o, 1, "CONFLICT (content): merge conflict in %s",
 					       ren1_dst);
 					clean_merge = 0;
 
-					if (!index_only)
+					if (!o->call_depth)
 						update_stages(ren1_dst,
 							      ren1->pair->one,
 							      ren1->pair->two,
 							      ren2->pair->two,
 							      1 /* clear */);
 				}
-				update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
+				update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 			}
 		} else {
 			/* Renamed in 1, maybe changed in 2 */
-			struct path_list_item *item;
+			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(1, ren1_src, index_only || stage == 3);
+			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;
@@ -1273,49 +888,50 @@ static int process_renames(struct path_list *a_renames,
 
 			try_merge = 0;
 
-			if (path_list_has_path(&current_directory_set, ren1_dst)) {
+			if (string_list_has_string(&o->current_directory_set, ren1_dst)) {
 				clean_merge = 0;
-				output(1, "CONFLICT (rename/directory): Renamed %s->%s in %s "
+				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(ren1, branch1);
+				conflict_rename_dir(o, ren1, branch1);
 			} else if (sha_eq(src_other.sha1, null_sha1)) {
 				clean_merge = 0;
-				output(1, "CONFLICT (rename/delete): Renamed %s->%s in %s "
+				output(o, 1, "CONFLICT (rename/delete): Rename %s->%s in %s "
 				       "and deleted in %s",
 				       ren1_src, ren1_dst, branch1,
 				       branch2);
-				update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
+				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(1, "CONFLICT (rename/add): Renamed %s->%s in %s. "
+				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(ren1_dst, branch2);
-				output(1, "Added as %s instead", new_path);
-				update_file(0, dst_other.sha1, dst_other.mode, new_path);
-			} else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
+				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(1, "CONFLICT (rename/rename): Renamed %s->%s in %s. "
-				       "Renamed %s->%s in %s",
+				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(ren1, branch1, ren2, branch2);
+				conflict_rename_rename_2(o, ren1, branch1, ren2, branch2);
 			} else
 				try_merge = 1;
 
 			if (try_merge) {
-				struct diff_filespec *o, *a, *b;
+				struct diff_filespec *one, *a, *b;
 				struct merge_file_info mfi;
 				src_other.path = (char *)ren1_src;
 
-				o = ren1->pair->one;
+				one = ren1->pair->one;
 				if (a_renames == renames1) {
 					a = ren1->pair->two;
 					b = &src_other;
@@ -1323,8 +939,8 @@ static int process_renames(struct path_list *a_renames,
 					b = ren1->pair->two;
 					a = &src_other;
 				}
-				mfi = merge_file(o, a, b,
-						a_branch, b_branch);
+				mfi = merge_file(o, one, a, b,
+						o->branch1, o->branch2);
 
 				if (mfi.clean &&
 				    sha_eq(mfi.sha, ren1->pair->two->sha1) &&
@@ -1334,28 +950,28 @@ static int process_renames(struct path_list *a_renames,
 					 * t6022 test. If you change
 					 * it update the test too.
 					 */
-					output(3, "Skipped %s (merged same as existing)", ren1_dst);
+					output(o, 3, "Skipped %s (merged same as existing)", ren1_dst);
 				else {
 					if (mfi.merge || !mfi.clean)
-						output(1, "Renamed %s => %s", ren1_src, ren1_dst);
+						output(o, 1, "Renaming %s => %s", ren1_src, ren1_dst);
 					if (mfi.merge)
-						output(2, "Auto-merged %s", ren1_dst);
+						output(o, 2, "Auto-merging %s", ren1_dst);
 					if (!mfi.clean) {
-						output(1, "CONFLICT (rename/modify): Merge conflict in %s",
+						output(o, 1, "CONFLICT (rename/modify): Merge conflict in %s",
 						       ren1_dst);
 						clean_merge = 0;
 
-						if (!index_only)
+						if (!o->call_depth)
 							update_stages(ren1_dst,
-								      o, a, b, 1);
+								      one, a, b, 1);
 					}
-					update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
+					update_file(o, mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 				}
 			}
 		}
 	}
-	path_list_clear(&a_by_dst, 0);
-	path_list_clear(&b_by_dst, 0);
+	string_list_clear(&a_by_dst, 0);
+	string_list_clear(&b_by_dst, 0);
 
 	return clean_merge;
 }
@@ -1366,9 +982,8 @@ static unsigned char *stage_sha(const unsigned char *sha, unsigned mode)
 }
 
 /* Per entry merge function */
-static int process_entry(const char *path, struct stage_data *entry,
-			 const char *branch1,
-			 const char *branch2)
+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");
@@ -1390,24 +1005,24 @@ static int process_entry(const char *path, struct stage_data *entry,
 			/* Deleted in both or deleted in one and
 			 * unchanged in the other */
 			if (a_sha)
-				output(2, "Removed %s", path);
+				output(o, 2, "Removing %s", path);
 			/* do not touch working file if it did not exist */
-			remove_file(1, path, !a_sha);
+			remove_file(o, 1, path, !a_sha);
 		} else {
 			/* Deleted in one and changed in the other */
 			clean_merge = 0;
 			if (!a_sha) {
-				output(1, "CONFLICT (delete/modify): %s deleted in %s "
+				output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
 				       "and modified in %s. Version %s of %s left in tree.",
-				       path, branch1,
-				       branch2, branch2, path);
-				update_file(0, b_sha, b_mode, path);
+				       path, o->branch1,
+				       o->branch2, o->branch2, path);
+				update_file(o, 0, b_sha, b_mode, path);
 			} else {
-				output(1, "CONFLICT (delete/modify): %s deleted in %s "
+				output(o, 1, "CONFLICT (delete/modify): %s deleted in %s "
 				       "and modified in %s. Version %s of %s left in tree.",
-				       path, branch2,
-				       branch1, branch1, path);
-				update_file(0, a_sha, a_mode, path);
+				       path, o->branch2,
+				       o->branch1, o->branch1, path);
+				update_file(o, 0, a_sha, a_mode, path);
 			}
 		}
 
@@ -1421,67 +1036,67 @@ static int process_entry(const char *path, struct stage_data *entry,
 		const char *conf;
 
 		if (a_sha) {
-			add_branch = branch1;
-			other_branch = branch2;
+			add_branch = o->branch1;
+			other_branch = o->branch2;
 			mode = a_mode;
 			sha = a_sha;
 			conf = "file/directory";
 		} else {
-			add_branch = branch2;
-			other_branch = branch1;
+			add_branch = o->branch2;
+			other_branch = o->branch1;
 			mode = b_mode;
 			sha = b_sha;
 			conf = "directory/file";
 		}
-		if (path_list_has_path(&current_directory_set, path)) {
-			const char *new_path = unique_path(path, add_branch);
+		if (string_list_has_string(&o->current_directory_set, path)) {
+			const char *new_path = unique_path(o, path, add_branch);
 			clean_merge = 0;
-			output(1, "CONFLICT (%s): There is a directory with name %s in %s. "
-			       "Added %s as %s",
+			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(0, path, 0);
-			update_file(0, sha, mode, new_path);
+			remove_file(o, 0, path, 0);
+			update_file(o, 0, sha, mode, new_path);
 		} else {
-			output(2, "Added %s", path);
-			update_file(1, sha, mode, path);
+			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 o, a, b;
+		struct diff_filespec one, a, b;
 
 		if (!o_sha) {
 			reason = "add/add";
 			o_sha = (unsigned char *)null_sha1;
 		}
-		output(2, "Auto-merged %s", path);
-		o.path = a.path = b.path = (char *)path;
-		hashcpy(o.sha1, o_sha);
-		o.mode = o_mode;
+		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, &a, &b,
-				 branch1, branch2);
+		mfi = merge_file(o, &one, &a, &b,
+				 o->branch1, o->branch2);
 
 		clean_merge = mfi.clean;
 		if (mfi.clean)
-			update_file(1, mfi.sha, mfi.mode, path);
+			update_file(o, 1, mfi.sha, mfi.mode, path);
 		else if (S_ISGITLINK(mfi.mode))
-			output(1, "CONFLICT (submodule): Merge conflict in %s "
+			output(o, 1, "CONFLICT (submodule): Merge conflict in %s "
 			       "- needs %s", path, sha1_to_hex(b.sha1));
 		else {
-			output(1, "CONFLICT (%s): Merge conflict in %s",
+			output(o, 1, "CONFLICT (%s): Merge conflict in %s",
 					reason, path);
 
-			if (index_only)
-				update_file(0, mfi.sha, mfi.mode, path);
+			if (o->call_depth)
+				update_file(o, 0, mfi.sha, mfi.mode, path);
 			else
-				update_file_flags(mfi.sha, mfi.mode, path,
+				update_file_flags(o, mfi.sha, mfi.mode, path,
 					      0 /* update_cache */, 1 /* update_working_directory */);
 		}
 	} else if (!o_sha && !a_sha && !b_sha) {
@@ -1489,71 +1104,69 @@ static int process_entry(const char *path, struct stage_data *entry,
 		 * this entry was deleted altogether. a_mode == 0 means
 		 * we had that path and want to actively remove it.
 		 */
-		remove_file(1, path, !a_mode);
+		remove_file(o, 1, path, !a_mode);
 	} else
 		die("Fatal merge failure, shouldn't happen.");
 
 	return clean_merge;
 }
 
-static int merge_trees(struct tree *head,
-		       struct tree *merge,
-		       struct tree *common,
-		       const char *branch1,
-		       const char *branch2,
-		       struct tree **result)
+int merge_trees(struct merge_options *o,
+		struct tree *head,
+		struct tree *merge,
+		struct tree *common,
+		struct tree **result)
 {
 	int code, clean;
 
-	if (subtree_merge) {
+	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(0, "Already uptodate!");
+		output(o, 0, "Already uptodate!");
 		*result = head;
 		return 1;
 	}
 
-	code = git_merge_trees(index_only, common, head, merge);
+	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_index()) {
-		struct path_list *entries, *re_head, *re_merge;
+	if (unmerged_cache()) {
+		struct string_list *entries, *re_head, *re_merge;
 		int i;
-		path_list_clear(&current_file_set, 1);
-		path_list_clear(&current_directory_set, 1);
-		get_files_dirs(head);
-		get_files_dirs(merge);
+		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(head, common, head, merge, entries);
-		re_merge = get_renames(merge, common, head, merge, entries);
-		clean = process_renames(re_head, re_merge,
-				branch1, branch2);
+		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].path;
+			const char *path = entries->items[i].string;
 			struct stage_data *e = entries->items[i].util;
 			if (!e->processed
-				&& !process_entry(path, e, branch1, branch2))
+				&& !process_entry(o, path, e))
 				clean = 0;
 		}
 
-		path_list_clear(re_merge, 0);
-		path_list_clear(re_head, 0);
-		path_list_clear(entries, 1);
+		string_list_clear(re_merge, 0);
+		string_list_clear(re_head, 0);
+		string_list_clear(entries, 1);
 
 	}
 	else
 		clean = 1;
 
-	if (index_only)
-		*result = git_write_tree();
+	if (o->call_depth)
+		*result = write_tree_from_memory(o);
 
 	return clean;
 }
@@ -1573,22 +1186,21 @@ static struct commit_list *reverse_commit_list(struct commit_list *list)
  * Merge the commits h1 and h2, return the resulting virtual
  * commit object and a flag indicating the cleanness of the merge.
  */
-static int merge(struct commit *h1,
-		 struct commit *h2,
-		 const char *branch1,
-		 const char *branch2,
-		 struct commit_list *ca,
-		 struct commit **result)
+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(4)) {
-		output(4, "Merging:");
-		output_commit_title(h1);
-		output_commit_title(h2);
+	if (show(o, 4)) {
+		output(o, 4, "Merging:");
+		output_commit_title(o, h1);
+		output_commit_title(o, h2);
 	}
 
 	if (!ca) {
@@ -1596,10 +1208,10 @@ static int merge(struct commit *h1,
 		ca = reverse_commit_list(ca);
 	}
 
-	if (show(5)) {
-		output(5, "found %u common ancestor(s):", commit_list_count(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(iter->item);
+			output_commit_title(o, iter->item);
 	}
 
 	merged_common_ancestors = pop_commit(&ca);
@@ -1614,7 +1226,8 @@ static int merge(struct commit *h1,
 	}
 
 	for (iter = ca; iter; iter = iter->next) {
-		call_depth++;
+		const char *saved_b1, *saved_b2;
+		o->call_depth++;
 		/*
 		 * When the merge fails, the result contains files
 		 * with conflict markers. The cleanness flag is
@@ -1623,141 +1236,121 @@ static int merge(struct commit *h1,
 		 * "conflicts" were already resolved.
 		 */
 		discard_cache();
-		merge(merged_common_ancestors, iter->item,
-		      "Temporary merge branch 1",
-		      "Temporary merge branch 2",
-		      NULL,
-		      &merged_common_ancestors);
-		call_depth--;
+		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 (!call_depth) {
+	if (!o->call_depth)
 		read_cache();
-		index_only = 0;
-	} else
-		index_only = 1;
 
-	clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
-			    branch1, branch2, &mrtree);
+	clean = merge_trees(o, h1->tree, h2->tree, merged_common_ancestors->tree,
+			    &mrtree);
 
-	if (index_only) {
+	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();
+	flush_output(o);
 	return clean;
 }
 
-static const char *better_branch_name(const char *branch)
-{
-	static char githead_env[8 + 40 + 1];
-	char *name;
-
-	if (strlen(branch) != 40)
-		return branch;
-	sprintf(githead_env, "GITHEAD_%s", branch);
-	name = getenv(githead_env);
-	return name ? name : branch;
-}
-
-static struct commit *get_ref(const char *ref)
+static struct commit *get_ref(const unsigned char *sha1, const char *name)
 {
-	unsigned char sha1[20];
 	struct object *object;
 
-	if (get_sha1(ref, sha1))
-		die("Could not resolve ref '%s'", ref);
-	object = deref_tag(parse_object(sha1), ref, strlen(ref));
+	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,
-			better_branch_name(ref));
+		return make_virtual_commit((struct tree*)object, name);
 	if (object->type != OBJ_COMMIT)
 		return NULL;
 	if (parse_commit((struct commit *)object))
-		die("Could not parse commit '%s'", sha1_to_hex(object->sha1));
+		return NULL;
 	return (struct commit *)object;
 }
 
-static int merge_config(const char *var, const char *value)
+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")) {
-		verbosity = git_config_int(var, value);
+		o->verbosity = git_config_int(var, value);
 		return 0;
 	}
 	if (!strcasecmp(var, "diff.renamelimit")) {
-		rename_limit = git_config_int(var, value);
+		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_default_config(var, value);
+	return git_default_config(var, value, cb);
 }
 
-int main(int argc, char *argv[])
+void init_merge_options(struct merge_options *o)
 {
-	static const char *bases[20];
-	static unsigned bases_count = 0;
-	int i, clean;
-	const char *branch1, *branch2;
-	struct commit *result, *h1, *h2;
-	struct commit_list *ca = NULL;
-	struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
-	int index_fd;
-
-	if (argv[0]) {
-		int namelen = strlen(argv[0]);
-		if (8 < namelen &&
-		    !strcmp(argv[0] + namelen - 8, "-subtree"))
-			subtree_merge = 1;
-	}
-
-	git_config(merge_config);
+	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"))
-		verbosity = strtol(getenv("GIT_MERGE_VERBOSITY"), NULL, 10);
-
-	if (argc < 4)
-		die("Usage: %s <base>... -- <head> <remote> ...\n", argv[0]);
-
-	for (i = 1; i < argc; ++i) {
-		if (!strcmp(argv[i], "--"))
-			break;
-		if (bases_count < sizeof(bases)/sizeof(*bases))
-			bases[bases_count++] = argv[i];
-	}
-	if (argc - i != 3) /* "--" "<head>" "<remote>" */
-		die("Not handling anything other than two heads merge.");
-	if (verbosity >= 5)
-		buffer_output = 0;
-
-	branch1 = argv[++i];
-	branch2 = argv[++i];
-
-	h1 = get_ref(branch1);
-	h2 = get_ref(branch2);
-
-	branch1 = better_branch_name(branch1);
-	branch2 = better_branch_name(branch2);
-
-	if (show(3))
-		printf("Merging %s with %s\n", branch1, branch2);
-
-	index_fd = hold_locked_index(lock, 1);
-
-	for (i = 0; i < bases_count; i++) {
-		struct commit *ancestor = get_ref(bases[i]);
-		ca = commit_list_insert(ancestor, &ca);
-	}
-	clean = merge(h1, h2, branch1, branch2, ca, &result);
-
-	if (active_cache_changed &&
-	    (write_cache(index_fd, active_cache, active_nr) ||
-	     commit_locked_index(lock)))
-			die ("unable to write %s", get_index_file());
-
-	return clean ? 0: 1;
+		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;
 }