Merge branch 'master' into js/c-merge-recursive
authorJunio C Hamano <junkio@cox.net>
Sun, 13 Aug 2006 01:34:36 +0000 (18:34 -0700)
committerJunio C Hamano <junkio@cox.net>
Sun, 13 Aug 2006 01:35:14 +0000 (18:35 -0700)
Adjust to hold_lock_file_for_update() change on the master.

1  2 
Makefile
builtin-read-tree.c
cache.h
git-rebase.sh
merge-recursive.c
read-cache.c

diff --cc Makefile
index 81d26a0881eb813f556ff4cd45084b3f4ebad565,0761d6c6eddd7894f2d1625cfed0ef2623661a32..1c327c1d5c42ca73d4c55d5341d57606ea80ec61
+++ b/Makefile
@@@ -180,9 -185,8 +185,9 @@@ PROGRAMS = 
        git-unpack-objects$X git-update-server-info$X \
        git-upload-pack$X git-verify-pack$X \
        git-symbolic-ref$X \
-       git-name-rev$X git-pack-redundant$X git-repo-config$X git-var$X \
+       git-name-rev$X git-pack-redundant$X git-var$X \
 -      git-describe$X git-merge-tree$X git-blame$X git-imap-send$X
 +      git-describe$X git-merge-tree$X git-blame$X git-imap-send$X \
 +      git-merge-recur$X
  
  BUILT_INS = git-log$X git-whatchanged$X git-show$X git-update-ref$X \
        git-count-objects$X git-diff$X git-push$X git-mailsplit$X \
index 8869cedea1f9b07d78520858876cca614283d01b,71a7026df4bec244acdf36ef9559eecc5b65fae3..8da8acbb0a25f88073254e21936a6ad5c6d0cca4
@@@ -92,17 -874,17 +92,15 @@@ int cmd_read_tree(int argc, const char 
  {
        int i, newfd, stage = 0;
        unsigned char sha1[20];
 -      merge_fn_t fn = NULL;
 +      struct unpack_trees_options opts;
  
 -      df_conflict_list.next = &df_conflict_list;
 -      state.base_dir = "";
 -      state.force = 1;
 -      state.quiet = 1;
 -      state.refresh_cache = 1;
 +      memset(&opts, 0, sizeof(opts));
 +      opts.head_idx = -1;
  
 +      setup_git_directory();
        git_config(git_default_config);
  
-       newfd = hold_lock_file_for_update(&lock_file, get_index_file());
-       if (newfd < 0)
-               die("unable to create new index file");
+       newfd = hold_lock_file_for_update(&lock_file, get_index_file(), 1);
  
        git_config(git_default_config);
  
diff --cc cache.h
Simple merge
diff --cc git-rebase.sh
Simple merge
index 454e2935780ced518b85869b36d0a62d8129e89c,0000000000000000000000000000000000000000..048cca1d13fa72540b6e989618f1490c04dc1eaa
mode 100644,000000..100644
--- /dev/null
@@@ -1,1358 -1,0 +1,1356 @@@
-       int fd = hold_lock_file_for_update(lock, current_index_file);
-       if (fd < 0)
-               die("could not lock %s", lock->filename);
 +/*
 + * 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 <stdarg.h>
 +#include <string.h>
 +#include <assert.h>
 +#include <sys/wait.h>
 +#include <sys/types.h>
 +#include <sys/stat.h>
 +#include <time.h>
 +#include "cache.h"
 +#include "cache-tree.h"
 +#include "commit.h"
 +#include "blob.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"
 +
 +/*
 + * A virtual commit has
 + * - (const char *)commit->util set to the name, and
 + * - *(int *)commit->object.sha1 set to the virtual id.
 + */
 +
 +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 *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;
 +}
 +
 +/*
 + * 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 && memcmp(a, b, 20) == 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 struct path_list current_file_set = {NULL, 0, 0, 1};
 +static struct path_list current_directory_set = {NULL, 0, 0, 1};
 +
 +static int output_indent = 0;
 +
 +static void output(const char *fmt, ...)
 +{
 +      va_list args;
 +      int i;
 +      for (i = output_indent; i--;)
 +              fputs("  ", stdout);
 +      va_start(args, fmt);
 +      vfprintf(stdout, fmt, args);
 +      va_end(args);
 +      fputc('\n', stdout);
 +}
 +
 +static void output_commit_title(struct commit *commit)
 +{
 +      int i;
 +      for (i = output_indent; i--;)
 +              fputs("  ", stdout);
 +      if (commit->util)
 +              printf("virtual %s\n", (char *)commit->util);
 +      else {
 +              printf("%s ", sha1_to_hex(commit->object.sha1));
 +              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 const char *current_index_file = NULL;
 +static const char *original_index_file;
 +static const char *temporary_index_file;
 +static int cache_dirty = 0;
 +
 +static int flush_cache(void)
 +{
 +      /* flush temporary index */
 +      struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
++      int fd = hold_lock_file_for_update(lock, current_index_file, 1);
 +      if (write_cache(fd, active_cache, active_nr) ||
 +                      close(fd) || commit_lock_file(lock))
 +              die ("unable to write %s", current_index_file);
 +      discard_cache();
 +      cache_dirty = 0;
 +      return 0;
 +}
 +
 +static void setup_index(int temp)
 +{
 +      current_index_file = temp ? temporary_index_file: original_index_file;
 +      if (cache_dirty) {
 +              discard_cache();
 +              cache_dirty = 0;
 +      }
 +      unlink(temporary_index_file);
 +      discard_cache();
 +}
 +
 +static struct cache_entry *make_cache_entry(unsigned int mode,
 +              const unsigned char *sha1, const char *path, int stage, int refresh)
 +{
 +      int size, len;
 +      struct cache_entry *ce;
 +
 +      if (!verify_path(path))
 +              return NULL;
 +
 +      len = strlen(path);
 +      size = cache_entry_size(len);
 +      ce = xcalloc(1, size);
 +
 +      memcpy(ce->sha1, sha1, 20);
 +      memcpy(ce->name, path, len);
 +      ce->ce_flags = create_ce_flags(len, stage);
 +      ce->ce_mode = create_ce_mode(mode);
 +
 +      if (refresh)
 +              return refresh_cache_entry(ce, 0);
 +
 +      return ce;
 +}
 +
 +static int add_cacheinfo(unsigned int mode, const unsigned char *sha1,
 +              const char *path, int stage, int refresh, int options)
 +{
 +      struct cache_entry *ce;
 +      if (!cache_dirty)
 +              read_cache_from(current_index_file);
 +      cache_dirty++;
 +      ce = make_cache_entry(mode, sha1 ? sha1 : null_sha1, path, stage, refresh);
 +      if (!ce)
 +              return error("cache_addinfo failed: %s", strerror(cache_errno));
 +      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 int git_read_tree(struct tree *tree)
 +{
 +      int rc;
 +      struct object_list *trees = NULL;
 +      struct unpack_trees_options opts;
 +
 +      if (cache_dirty)
 +              die("read-tree with dirty cache");
 +
 +      memset(&opts, 0, sizeof(opts));
 +      object_list_append(&tree->object, &trees);
 +      rc = unpack_trees(trees, &opts);
 +      cache_tree_free(&active_cache_tree);
 +
 +      if (rc == 0)
 +              cache_dirty = 1;
 +
 +      return rc;
 +}
 +
 +static int git_merge_trees(int index_only,
 +                         struct tree *common,
 +                         struct tree *head,
 +                         struct tree *merge)
 +{
 +      int rc;
 +      struct object_list *trees = NULL;
 +      struct unpack_trees_options opts;
 +
 +      if (!cache_dirty) {
 +              read_cache_from(current_index_file);
 +              cache_dirty = 1;
 +      }
 +
 +      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;
 +
 +      object_list_append(&common->object, &trees);
 +      object_list_append(&head->object, &trees);
 +      object_list_append(&merge->object, &trees);
 +
 +      rc = unpack_trees(trees, &opts);
 +      cache_tree_free(&active_cache_tree);
 +
 +      cache_dirty = 1;
 +
 +      return rc;
 +}
 +
 +static struct tree *git_write_tree(void)
 +{
 +      struct tree *result = NULL;
 +
 +      if (cache_dirty) {
 +              unsigned i;
 +              for (i = 0; i < active_nr; i++) {
 +                      struct cache_entry *ce = active_cache[i];
 +                      if (ce_stage(ce))
 +                              return NULL;
 +              }
 +      } else
 +              read_cache_from(current_index_file);
 +
 +      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);
 +
 +      flush_cache();
 +      cache_dirty = 0;
 +
 +      return result;
 +}
 +
 +static int save_files_dirs(const unsigned char *sha1,
 +              const char *base, int baselen, const char *path,
 +              unsigned int mode, int stage)
 +{
 +      int len = strlen(path);
 +      char *newpath = malloc(baselen + len + 1);
 +      memcpy(newpath, base, baselen);
 +      memcpy(newpath + baselen, path, len);
 +      newpath[baselen + len] = '\0';
 +
 +      if (S_ISDIR(mode))
 +              path_list_insert(newpath, &current_directory_set);
 +      else
 +              path_list_insert(newpath, &current_file_set);
 +      free(newpath);
 +
 +      return READ_TREE_RECURSIVE;
 +}
 +
 +static int get_files_dirs(struct tree *tree)
 +{
 +      int n;
 +      if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0)
 +              return 0;
 +      n = current_file_set.nr + current_directory_set.nr;
 +      return n;
 +}
 +
 +/*
 + * Returns a 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 path_list *entries)
 +{
 +      struct path_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 = path_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 path_list *get_unmerged(void)
 +{
 +      struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
 +      int i;
 +
 +      unmerged->strdup_paths = 1;
 +      if (!cache_dirty) {
 +              read_cache_from(current_index_file);
 +              cache_dirty++;
 +      }
 +      for (i = 0; i < active_nr; i++) {
 +              struct path_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);
 +              if (!item) {
 +                      item = path_list_insert(ce->name, unmerged);
 +                      item->util = xcalloc(1, sizeof(struct stage_data));
 +              }
 +              e = item->util;
 +              e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
 +              memcpy(e->stages[ce_stage(ce)].sha, ce->sha1, 20);
 +      }
 +
 +      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 occured 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 path_list *get_renames(struct tree *tree,
 +                                      struct tree *o_tree,
 +                                      struct tree *a_tree,
 +                                      struct tree *b_tree,
 +                                      struct path_list *entries)
 +{
 +      int i;
 +      struct path_list *renames;
 +      struct diff_options opts;
 +
 +      renames = xcalloc(1, sizeof(struct path_list));
 +      diff_setup(&opts);
 +      opts.recursive = 1;
 +      opts.detect_rename = DIFF_DETECT_RENAME;
 +      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 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 = path_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);
 +              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->util = re;
 +      }
 +      opts.output_format = DIFF_FORMAT_NO_OUTPUT;
 +      diff_queued_diff.nr = 0;
 +      diff_flush(&opts);
 +      return renames;
 +}
 +
 +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_path(const char *name)
 +{
 +      int ret, len;
 +      char *slash, *dirs;
 +
 +      ret = unlink(name);
 +      if (ret)
 +              return ret;
 +      len = strlen(name);
 +      dirs = malloc(len+1);
 +      memcpy(dirs, name, len);
 +      dirs[len] = '\0';
 +      while ((slash = strrchr(name, '/'))) {
 +              *slash = '\0';
 +              len = slash - name;
 +              if (rmdir(name) != 0)
 +                      break;
 +      }
 +      free(dirs);
 +      return ret;
 +}
 +
 +int remove_file(int clean, const char *path)
 +{
 +      int update_cache = index_only || clean;
 +      int update_working_directory = !index_only;
 +
 +      if (update_cache) {
 +              if (!cache_dirty)
 +                      read_cache_from(current_index_file);
 +              cache_dirty++;
 +              if (remove_file_from_cache(path))
 +                      return -1;
 +      }
 +      if (update_working_directory)
 +      {
 +              unlink(path);
 +              if (errno != ENOENT || errno != EISDIR)
 +                      return -1;
 +              remove_path(path);
 +      }
 +      return 0;
 +}
 +
 +static char *unique_path(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 (path_list_has_path(&current_file_set, newpath) ||
 +             path_list_has_path(&current_directory_set, newpath) ||
 +             lstat(newpath, &st) == 0)
 +              sprintf(p, "_%d", suffix++);
 +
 +      path_list_insert(newpath, &current_file_set);
 +      return newpath;
 +}
 +
 +static int mkdir_p(const char *path, unsigned long mode)
 +{
 +      /* path points to cache entries, so strdup before messing with it */
 +      char *buf = strdup(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) {
 +              long ret = xwrite(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;
 +      }
 +}
 +
 +void update_file_flags(const unsigned char *sha,
 +                     unsigned mode,
 +                     const char *path,
 +                     int update_cache,
 +                     int update_wd)
 +{
 +      if (index_only)
 +              update_wd = 0;
 +
 +      if (update_wd) {
 +              char type[20];
 +              void *buf;
 +              unsigned long size;
 +
 +              buf = read_sha1_file(sha, type, &size);
 +              if (!buf)
 +                      die("cannot read object %s '%s'", sha1_to_hex(sha), path);
 +              if (strcmp(type, blob_type) != 0)
 +                      die("blob expected for %s '%s'", sha1_to_hex(sha), path);
 +
 +              if (S_ISREG(mode)) {
 +                      int fd;
 +                      if (mkdir_p(path, 0777))
 +                              die("failed to create path %s: %s", path, strerror(errno));
 +                      unlink(path);
 +                      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 = malloc(size + 1);
 +                      memcpy(lnk, buf, size);
 +                      lnk[size] = '\0';
 +                      mkdir_p(path, 0777);
 +                      unlink(lnk);
 +                      symlink(lnk, path);
 +              } else
 +                      die("do not know what to do with %06o %s '%s'",
 +                          mode, sha1_to_hex(sha), path);
 +      }
 +      if (update_cache)
 +              add_cacheinfo(mode, sha, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
 +}
 +
 +void update_file(int clean,
 +              const unsigned char *sha,
 +              unsigned mode,
 +              const char *path)
 +{
 +      update_file_flags(sha, mode, path, index_only || clean, !index_only);
 +}
 +
 +/* Low level file merging, update and removal */
 +
 +struct merge_file_info
 +{
 +      unsigned char sha[20];
 +      unsigned mode;
 +      unsigned clean:1,
 +               merge:1;
 +};
 +
 +static char *git_unpack_file(const unsigned char *sha1, char *path)
 +{
 +      void *buf;
 +      char type[20];
 +      unsigned long size;
 +      int fd;
 +
 +      buf = read_sha1_file(sha1, type, &size);
 +      if (!buf || strcmp(type, blob_type))
 +              die("unable to read blob object %s", sha1_to_hex(sha1));
 +
 +      strcpy(path, ".merge_file_XXXXXX");
 +      fd = mkstemp(path);
 +      if (fd < 0)
 +              die("unable to create temp-file");
 +      flush_buffer(fd, buf, size);
 +      close(fd);
 +      return path;
 +}
 +
 +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)
 +{
 +      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;
 +                      memcpy(result.sha, a->sha1, 20);
 +              } else {
 +                      result.mode = b->mode;
 +                      memcpy(result.sha, b->sha1, 20);
 +              }
 +      } else {
 +              if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
 +                      result.merge = 1;
 +
 +              result.mode = a->mode == o->mode ? b->mode: a->mode;
 +
 +              if (sha_eq(a->sha1, o->sha1))
 +                      memcpy(result.sha, b->sha1, 20);
 +              else if (sha_eq(b->sha1, o->sha1))
 +                      memcpy(result.sha, a->sha1, 20);
 +              else if (S_ISREG(a->mode)) {
 +                      int code = 1, fd;
 +                      struct stat st;
 +                      char orig[PATH_MAX];
 +                      char src1[PATH_MAX];
 +                      char src2[PATH_MAX];
 +                      const char *argv[] = {
 +                              "merge", "-L", NULL, "-L", NULL, "-L", NULL,
 +                              NULL, NULL, NULL,
 +                              NULL
 +                      };
 +                      char *la, *lb, *lo;
 +
 +                      git_unpack_file(o->sha1, orig);
 +                      git_unpack_file(a->sha1, src1);
 +                      git_unpack_file(b->sha1, src2);
 +
 +                      argv[2] = la = strdup(mkpath("%s/%s", branch1, a->path));
 +                      argv[6] = lb = strdup(mkpath("%s/%s", branch2, b->path));
 +                      argv[4] = lo = strdup(mkpath("orig/%s", o->path));
 +                      argv[7] = src1;
 +                      argv[8] = orig;
 +                      argv[9] = src2,
 +
 +                      code = run_command_v(10, argv);
 +
 +                      free(la);
 +                      free(lb);
 +                      free(lo);
 +                      if (code && code < -256) {
 +                              die("Failed to execute 'merge'. merge(1) is used as the "
 +                                  "file-level merge tool. Is 'merge' in your path?");
 +                      }
 +                      fd = open(src1, O_RDONLY);
 +                      if (fd < 0 || fstat(fd, &st) < 0 ||
 +                                      index_fd(result.sha, fd, &st, 1,
 +                                              "blob"))
 +                              die("Unable to add %s to database", src1);
 +
 +                      unlink(orig);
 +                      unlink(src1);
 +                      unlink(src2);
 +
 +                      result.clean = WEXITSTATUS(code) == 0;
 +              } else {
 +                      if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
 +                              die("cannot merge modes?");
 +
 +                      memcpy(result.sha, a->sha1, 20);
 +
 +                      if (!sha_eq(a->sha1, b->sha1))
 +                              result.clean = 0;
 +              }
 +      }
 +
 +      return result;
 +}
 +
 +static void conflict_rename_rename(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 (path_list_has_path(&current_directory_set, ren1_dst)) {
 +              dst_name1 = del[delp++] = unique_path(ren1_dst, branch1);
 +              output("%s is a directory in %s adding as %s instead",
 +                     ren1_dst, branch2, dst_name1);
 +              remove_file(0, ren1_dst);
 +      }
 +      if (path_list_has_path(&current_directory_set, ren2_dst)) {
 +              dst_name2 = del[delp++] = unique_path(ren2_dst, branch2);
 +              output("%s is a directory in %s adding as %s instead",
 +                     ren2_dst, branch1, dst_name2);
 +              remove_file(0, ren2_dst);
 +      }
 +      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 rename *ren1,
 +                              const char *branch1)
 +{
 +      char *new_path = unique_path(ren1->pair->two->path, branch1);
 +      output("Renaming %s to %s instead", ren1->pair->one->path, new_path);
 +      remove_file(0, ren1->pair->two->path);
 +      update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, new_path);
 +      free(new_path);
 +}
 +
 +static void conflict_rename_rename_2(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("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);
 +      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);
 +      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)
 +{
 +      int clean_merge = 1, i, j;
 +      struct path_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
 +                      = 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
 +                      = 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 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].path,
 +                                      b_renames->items[j].path);
 +                      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 = a_branch;
 +                      branch2 = b_branch;
 +              } else {
 +                      struct rename *tmp;
 +                      renames1 = b_renames;
 +                      renames2 = a_renames;
 +                      renames2Dst = &a_by_dst;
 +                      branch1 = b_branch;
 +                      branch2 = a_branch;
 +                      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("CONFLICT (rename/rename): "
 +                                     "Rename %s->%s in branch %s "
 +                                     "rename %s->%s in %s",
 +                                     src, ren1_dst, branch1,
 +                                     src, ren2_dst, branch2);
 +                              conflict_rename_rename(ren1, branch1, ren2, branch2);
 +                      } else {
 +                              struct merge_file_info mfi;
 +                              remove_file(1, ren1_src);
 +                              mfi = merge_file(ren1->pair->one,
 +                                               ren1->pair->two,
 +                                               ren2->pair->two,
 +                                               branch1,
 +                                               branch2);
 +                              if (mfi.merge || !mfi.clean)
 +                                      output("Renaming %s->%s", src, ren1_dst);
 +
 +                              if (mfi.merge)
 +                                      output("Auto-merging %s", ren1_dst);
 +
 +                              if (!mfi.clean) {
 +                                      output("CONFLICT (content): merge conflict in %s",
 +                                             ren1_dst);
 +                                      clean_merge = 0;
 +
 +                                      if (!index_only)
 +                                              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);
 +                      }
 +              } else {
 +                      /* Renamed in 1, maybe changed in 2 */
 +                      struct path_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);
 +
 +                      memcpy(src_other.sha1,
 +                                      ren1->src_entry->stages[stage].sha, 20);
 +                      src_other.mode = ren1->src_entry->stages[stage].mode;
 +                      memcpy(dst_other.sha1,
 +                                      ren1->dst_entry->stages[stage].sha, 20);
 +                      dst_other.mode = ren1->dst_entry->stages[stage].mode;
 +
 +                      try_merge = 0;
 +
 +                      if (path_list_has_path(&current_directory_set, ren1_dst)) {
 +                              clean_merge = 0;
 +                              output("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);
 +                      } else if (sha_eq(src_other.sha1, null_sha1)) {
 +                              clean_merge = 0;
 +                              output("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);
 +                      } else if (!sha_eq(dst_other.sha1, null_sha1)) {
 +                              const char *new_path;
 +                              clean_merge = 0;
 +                              try_merge = 1;
 +                              output("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("Adding 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))) {
 +                              ren2 = item->util;
 +                              clean_merge = 0;
 +                              ren2->processed = 1;
 +                              output("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);
 +                      } else
 +                              try_merge = 1;
 +
 +                      if (try_merge) {
 +                              struct diff_filespec *o, *a, *b;
 +                              struct merge_file_info mfi;
 +                              src_other.path = (char *)ren1_src;
 +
 +                              o = 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, a, b,
 +                                              a_branch, b_branch);
 +
 +                              if (mfi.merge || !mfi.clean)
 +                                      output("Renaming %s => %s", ren1_src, ren1_dst);
 +                              if (mfi.merge)
 +                                      output("Auto-merging %s", ren1_dst);
 +                              if (!mfi.clean) {
 +                                      output("CONFLICT (rename/modify): Merge conflict in %s",
 +                                             ren1_dst);
 +                                      clean_merge = 0;
 +
 +                                      if (!index_only)
 +                                              update_stages(ren1_dst,
 +                                                              o, a, b, 1);
 +                              }
 +                              update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 +                      }
 +              }
 +      }
 +      path_list_clear(&a_by_dst, 0);
 +      path_list_clear(&b_by_dst, 0);
 +
 +      if (cache_dirty)
 +              flush_cache();
 +      return clean_merge;
 +}
 +
 +static unsigned char *has_sha(const unsigned char *sha)
 +{
 +      return memcmp(sha, null_sha1, 20) == 0 ? NULL: (unsigned char *)sha;
 +}
 +
 +/* Per entry merge function */
 +static int process_entry(const char *path, struct stage_data *entry,
 +                       const char *branch1,
 +                       const char *branch2)
 +{
 +      /*
 +      printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
 +      print_index_entry("\tpath: ", entry);
 +      */
 +      int clean_merge = 1;
 +      unsigned char *o_sha = has_sha(entry->stages[1].sha);
 +      unsigned char *a_sha = has_sha(entry->stages[2].sha);
 +      unsigned char *b_sha = has_sha(entry->stages[3].sha);
 +      unsigned o_mode = entry->stages[1].mode;
 +      unsigned a_mode = entry->stages[2].mode;
 +      unsigned b_mode = entry->stages[3].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("Removing %s", path);
 +                      remove_file(1, path);
 +              } else {
 +                      /* Deleted in one and changed in the other */
 +                      clean_merge = 0;
 +                      if (!a_sha) {
 +                              output("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);
 +                      } else {
 +                              output("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);
 +                      }
 +              }
 +
 +      } 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 = branch1;
 +                      other_branch = branch2;
 +                      mode = a_mode;
 +                      sha = a_sha;
 +                      conf = "file/directory";
 +              } else {
 +                      add_branch = branch2;
 +                      other_branch = 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);
 +                      clean_merge = 0;
 +                      output("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);
 +                      update_file(0, sha, mode, new_path);
 +              } else {
 +                      output("Adding %s", path);
 +                      update_file(1, sha, mode, path);
 +              }
 +      } else if (!o_sha && a_sha && b_sha) {
 +              /* Case C: Added in both (check for same permissions). */
 +              if (sha_eq(a_sha, b_sha)) {
 +                      if (a_mode != b_mode) {
 +                              clean_merge = 0;
 +                              output("CONFLICT: File %s added identically in both branches, "
 +                                     "but permissions conflict %06o->%06o",
 +                                     path, a_mode, b_mode);
 +                              output("CONFLICT: adding with permission: %06o", a_mode);
 +                              update_file(0, a_sha, a_mode, path);
 +                      } else {
 +                              /* This case is handled by git-read-tree */
 +                              assert(0 && "This case must be handled by git-read-tree");
 +                      }
 +              } else {
 +                      const char *new_path1, *new_path2;
 +                      clean_merge = 0;
 +                      new_path1 = unique_path(path, branch1);
 +                      new_path2 = unique_path(path, branch2);
 +                      output("CONFLICT (add/add): File %s added non-identically "
 +                             "in both branches. Adding as %s and %s instead.",
 +                             path, new_path1, new_path2);
 +                      remove_file(0, path);
 +                      update_file(0, a_sha, a_mode, new_path1);
 +                      update_file(0, b_sha, b_mode, new_path2);
 +              }
 +
 +      } else if (o_sha && a_sha && b_sha) {
 +              /* case D: Modified in both, but differently. */
 +              struct merge_file_info mfi;
 +              struct diff_filespec o, a, b;
 +
 +              output("Auto-merging %s", path);
 +              o.path = a.path = b.path = (char *)path;
 +              memcpy(o.sha1, o_sha, 20);
 +              o.mode = o_mode;
 +              memcpy(a.sha1, a_sha, 20);
 +              a.mode = a_mode;
 +              memcpy(b.sha1, b_sha, 20);
 +              b.mode = b_mode;
 +
 +              mfi = merge_file(&o, &a, &b,
 +                               branch1, branch2);
 +
 +              if (mfi.clean)
 +                      update_file(1, mfi.sha, mfi.mode, path);
 +              else {
 +                      clean_merge = 0;
 +                      output("CONFLICT (content): Merge conflict in %s", path);
 +
 +                      if (index_only)
 +                              update_file(0, mfi.sha, mfi.mode, path);
 +                      else
 +                              update_file_flags(mfi.sha, mfi.mode, path,
 +                                            0 /* update_cache */, 1 /* update_working_directory */);
 +              }
 +      } else
 +              die("Fatal merge failure, shouldn't happen.");
 +
 +      if (cache_dirty)
 +              flush_cache();
 +
 +      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 code, clean;
 +      if (sha_eq(common->object.sha1, merge->object.sha1)) {
 +              output("Already uptodate!");
 +              *result = head;
 +              return 1;
 +      }
 +
 +      code = git_merge_trees(index_only, 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));
 +
 +      *result = git_write_tree();
 +
 +      if (!*result) {
 +              struct path_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);
 +
 +              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);
 +              for (i = 0; i < entries->nr; i++) {
 +                      const char *path = entries->items[i].path;
 +                      struct stage_data *e = entries->items[i].util;
 +                      if (e->processed)
 +                              continue;
 +                      if (!process_entry(path, e, branch1, branch2))
 +                              clean = 0;
 +              }
 +
 +              path_list_clear(re_merge, 0);
 +              path_list_clear(re_head, 0);
 +              path_list_clear(entries, 1);
 +
 +              if (clean || index_only)
 +                      *result = git_write_tree();
 +              else
 +                      *result = NULL;
 +      } else {
 +              clean = 1;
 +              printf("merging of trees %s and %s resulted in %s\n",
 +                     sha1_to_hex(head->object.sha1),
 +                     sha1_to_hex(merge->object.sha1),
 +                     sha1_to_hex((*result)->object.sha1));
 +      }
 +
 +      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 cleaness of the merge.
 + */
 +static
 +int merge(struct commit *h1,
 +                        struct commit *h2,
 +                        const char *branch1,
 +                        const char *branch2,
 +                        int call_depth /* =0 */,
 +                        struct commit *ancestor /* =None */,
 +                        struct commit **result)
 +{
 +      struct commit_list *ca = NULL, *iter;
 +      struct commit *merged_common_ancestors;
 +      struct tree *mrtree;
 +      int clean;
 +
 +      output("Merging:");
 +      output_commit_title(h1);
 +      output_commit_title(h2);
 +
 +      if (ancestor)
 +              commit_list_insert(ancestor, &ca);
 +      else
 +              ca = reverse_commit_list(get_merge_bases(h1, h2, 1));
 +
 +      output("found %u common ancestor(s):", commit_list_count(ca));
 +      for (iter = ca; iter; iter = iter->next)
 +              output_commit_title(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));
 +              unsigned char hdr[40];
 +              int hdrlen;
 +
 +              tree->object.parsed = 1;
 +              tree->object.type = OBJ_TREE;
 +              write_sha1_file_prepare(NULL, 0, tree_type, tree->object.sha1,
 +                                      hdr, &hdrlen);
 +              merged_common_ancestors = make_virtual_commit(tree, "ancestor");
 +      }
 +
 +      for (iter = ca; iter; iter = iter->next) {
 +              output_indent = call_depth + 1;
 +              /*
 +               * When the merge fails, the result contains files
 +               * with conflict markers. The cleanness flag is
 +               * ignored, it was never acutally used, as result of
 +               * merge_trees has always overwritten it: the commited
 +               * "conflicts" were already resolved.
 +               */
 +              merge(merged_common_ancestors, iter->item,
 +                    "Temporary merge branch 1",
 +                    "Temporary merge branch 2",
 +                    call_depth + 1,
 +                    NULL,
 +                    &merged_common_ancestors);
 +              output_indent = call_depth;
 +
 +              if (!merged_common_ancestors)
 +                      die("merge returned no commit");
 +      }
 +
 +      if (call_depth == 0) {
 +              setup_index(0 /* $GIT_DIR/index */);
 +              index_only = 0;
 +      } else {
 +              setup_index(1 /* temporary index */);
 +              git_read_tree(h1->tree);
 +              index_only = 1;
 +      }
 +
 +      clean = merge_trees(h1->tree, h2->tree, merged_common_ancestors->tree,
 +                          branch1, branch2, &mrtree);
 +
 +      if (!ancestor && (clean || index_only)) {
 +              *result = make_virtual_commit(mrtree, "merged tree");
 +              commit_list_insert(h1, &(*result)->parents);
 +              commit_list_insert(h2, &(*result)->parents->next);
 +      } else
 +              *result = NULL;
 +
 +      return clean;
 +}
 +
 +static struct commit *get_ref(const char *ref)
 +{
 +      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));
 +      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 (struct commit *)object;
 +}
 +
 +int main(int argc, char *argv[])
 +{
 +      static const char *bases[2];
 +      static unsigned bases_count = 0;
 +      int i, clean;
 +      const char *branch1, *branch2;
 +      struct commit *result, *h1, *h2;
 +
 +      original_index_file = getenv("GIT_INDEX_FILE");
 +
 +      if (!original_index_file)
 +              original_index_file = strdup(git_path("index"));
 +
 +      temporary_index_file = strdup(git_path("mrg-rcrsv-tmp-idx"));
 +
 +      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.");
 +
 +      branch1 = argv[++i];
 +      branch2 = argv[++i];
 +      printf("Merging %s with %s\n", branch1, branch2);
 +
 +      h1 = get_ref(branch1);
 +      h2 = get_ref(branch2);
 +
 +      if (bases_count == 1) {
 +              struct commit *ancestor = get_ref(bases[0]);
 +              clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
 +      } else
 +              clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
 +
 +      if (cache_dirty)
 +              flush_cache();
 +
 +      return clean ? 0: 1;
 +}
 +
 +/*
 +vim: sw=8 noet
 +*/
diff --cc read-cache.c
Simple merge