Code

Merge branch 'lt/unitype' into js/c-merge-recursive
authorJunio C Hamano <junkio@cox.net>
Fri, 14 Jul 2006 06:38:11 +0000 (23:38 -0700)
committerJunio C Hamano <junkio@cox.net>
Fri, 14 Jul 2006 06:38:40 +0000 (23:38 -0700)
* lt/unitype:
  builtin-prune.c: forgot TYPE => OBJ changes.
  Remove TYPE_* constant macros and use object_type enums consistently.

1  2 
commit.c
merge-recursive.c
upload-pack.c

diff --cc commit.c
Simple merge
index cf81768ee9092dcb1bb55fb99aa4f1ed7fd5071c,0000000000000000000000000000000000000000..8d30519db177dd63ee360d6d08fb58d70a42a834
mode 100644,000000..100644
--- /dev/null
@@@ -1,1560 -1,0 +1,1560 @@@
-       if (object->type != TYPE_COMMIT)
 +/*
 + * 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 "path-list.h"
 +
 +/*#define DEBUG*/
 +
 +#ifdef DEBUG
 +#define debug(args, ...) fprintf(stderr, args, ## __VA_ARGS__)
 +#else
 +#define debug(args, ...)
 +#endif
 +
 +#ifdef DEBUG
 +#include "quote.h"
 +static void show_ce_entry(const char *tag, struct cache_entry *ce)
 +{
 +      if (tag && *tag &&
 +          (ce->ce_flags & htons(CE_VALID))) {
 +              static char alttag[4];
 +              memcpy(alttag, tag, 3);
 +              if (isalpha(tag[0]))
 +                      alttag[0] = tolower(tag[0]);
 +              else if (tag[0] == '?')
 +                      alttag[0] = '!';
 +              else {
 +                      alttag[0] = 'v';
 +                      alttag[1] = tag[0];
 +                      alttag[2] = ' ';
 +                      alttag[3] = 0;
 +              }
 +              tag = alttag;
 +      }
 +
 +      fprintf(stderr,"%s%06o %s %d\t",
 +                      tag,
 +                      ntohl(ce->ce_mode),
 +                      sha1_to_hex(ce->sha1),
 +                      ce_stage(ce));
 +      write_name_quoted("", 0, ce->name,
 +                      '\n', stderr);
 +      fputc('\n', stderr);
 +}
 +
 +static void ls_files() {
 +      int i;
 +      for (i = 0; i < active_nr; i++) {
 +              struct cache_entry *ce = active_cache[i];
 +              show_ce_entry("", ce);
 +      }
 +      fprintf(stderr, "---\n");
 +}
 +#endif
 +
 +/*
 + * A virtual commit has
 + * - (const char *)commit->util set to the name, and
 + * - *(int *)commit->object.sha1 set to the virtual id.
 + */
 +static const char *commit_title(struct commit *commit, int *len)
 +{
 +      const char *s = "(null commit)";
 +      *len = strlen(s);
 +
 +      if ( commit->util ) {
 +              s = commit->util;
 +              *len = strlen(s);
 +      } else {
 +              if ( parse_commit(commit) != 0 ) {
 +                      s = "(bad commit)";
 +                      *len = strlen(s);
 +              } else {
 +                      s = commit->buffer;
 +                      char prev = '\0';
 +                      while ( *s ) {
 +                              if ( '\n' == prev && '\n' == *s ) {
 +                                      ++s;
 +                                      break;
 +                              }
 +                              prev = *s++;
 +                      }
 +                      *len = 0;
 +                      while ( s[*len] && '\n' != s[*len] )
 +                              ++(*len);
 +              }
 +      }
 +      return s;
 +}
 +
 +static const char *commit_hex_sha1(const struct commit *commit)
 +{
 +      return commit->util ? "virtual" : commit ?
 +              sha1_to_hex(commit->object.sha1) : "undefined";
 +}
 +
 +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++;
 +      return commit;
 +}
 +
 +/*
 + * TODO: we should not have to copy the SHA1s around, but rather reference
 + * them. That way, sha_eq() is just sha1 == sha2.
 + */
 +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;
 +}
 +
 +static void memswp(void *p1, void *p2, unsigned n)
 +{
 +      unsigned char *a = p1, *b = p2;
 +      while ( n-- ) {
 +              *a ^= *b;
 +              *b ^= *a;
 +              *a ^= *b;
 +              ++a;
 +              ++b;
 +      }
 +}
 +
 +/*
 + * TODO: we should convert the merge_result users to
 + *    int blabla(..., struct commit **result)
 + * like everywhere else in git.
 + * Same goes for merge_tree_result and merge_file_info.
 + */
 +struct merge_result
 +{
 +      struct commit *commit;
 +      unsigned clean:1;
 +};
 +
 +struct merge_tree_result
 +{
 +      struct tree *tree;
 +      unsigned clean:1;
 +};
 +
 +/*
 + * TODO: check if we can just reuse the active_cache structure: it is already
 + * sorted (by name, stage).
 + * Only problem: do not write it when flushing the cache.
 + */
 +struct stage_data
 +{
 +      struct
 +      {
 +              unsigned mode;
 +              unsigned char sha[20];
 +      } stages[4];
 +      unsigned processed:1;
 +};
 +
 +static struct path_list currentFileSet = {NULL, 0, 0, 1};
 +static struct path_list currentDirectorySet = {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 const char *original_index_file;
 +static const char *temporary_index_file;
 +static int cache_dirty = 0;
 +
 +static int flush_cache()
 +{
 +      /* flush temporary index */
 +      struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
 +      int fd = hold_lock_file_for_update(lock, getenv("GIT_INDEX_FILE"));
 +      if (fd < 0)
 +              die("could not lock %s", temporary_index_file);
 +      if (write_cache(fd, active_cache, active_nr) ||
 +                      close(fd) || commit_lock_file(lock))
 +              die ("unable to write %s", getenv("GIT_INDEX_FILE"));
 +      discard_cache();
 +      cache_dirty = 0;
 +      return 0;
 +}
 +
 +static void setup_index(int temp)
 +{
 +      const char *idx = temp ? temporary_index_file: original_index_file;
 +      if (cache_dirty)
 +              die("fatal: cache changed flush_cache();");
 +      unlink(temporary_index_file);
 +      setenv("GIT_INDEX_FILE", idx, 1);
 +      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(getenv("GIT_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;
 +
 +/*
 + * TODO: this can be streamlined by refactoring builtin-read-tree.c
 + */
 +static int git_read_tree(const struct tree *tree)
 +{
 +#if 0
 +      fprintf(stderr, "GIT_INDEX_FILE='%s' git-read-tree %s\n",
 +              getenv("GIT_INDEX_FILE"),
 +              sha1_to_hex(tree->object.sha1));
 +#endif
 +      const char *argv[] = { "git-read-tree", NULL, NULL, };
 +      if (cache_dirty)
 +              die("read-tree with dirty cache");
 +      argv[1] = sha1_to_hex(tree->object.sha1);
 +      int rc = run_command_v(2, argv);
 +      return rc < 0 ? -1: rc;
 +}
 +
 +/*
 + * TODO: this can be streamlined by refactoring builtin-read-tree.c
 + */
 +static int git_merge_trees(const char *update_arg,
 +                         struct tree *common,
 +                         struct tree *head,
 +                         struct tree *merge)
 +{
 +#if 0
 +      fprintf(stderr, "GIT_INDEX_FILE='%s' git-read-tree %s -m %s %s %s\n",
 +              getenv("GIT_INDEX_FILE"),
 +              update_arg,
 +              sha1_to_hex(common->object.sha1),
 +              sha1_to_hex(head->object.sha1),
 +              sha1_to_hex(merge->object.sha1));
 +#endif
 +      const char *argv[] = {
 +              "git-read-tree", NULL, "-m", NULL, NULL, NULL,
 +              NULL,
 +      };
 +      if (cache_dirty)
 +              flush_cache();
 +      argv[1] = update_arg;
 +      argv[3] = sha1_to_hex(common->object.sha1);
 +      argv[4] = sha1_to_hex(head->object.sha1);
 +      argv[5] = sha1_to_hex(merge->object.sha1);
 +      int rc = run_command_v(6, argv);
 +      return rc < 0 ? -1: rc;
 +}
 +
 +/*
 + * TODO: this can be streamlined by refactoring builtin-write-tree.c
 + */
 +static struct tree *git_write_tree()
 +{
 +#if 0
 +      fprintf(stderr, "GIT_INDEX_FILE='%s' git-write-tree\n",
 +              getenv("GIT_INDEX_FILE"));
 +#endif
 +      if (cache_dirty)
 +              flush_cache();
 +      FILE *fp = popen("git-write-tree 2>/dev/null", "r");
 +      char buf[41];
 +      unsigned char sha1[20];
 +      int ch;
 +      unsigned i = 0;
 +      while ( (ch = fgetc(fp)) != EOF )
 +              if ( i < sizeof(buf)-1 && ch >= '0' && ch <= 'f' )
 +                      buf[i++] = ch;
 +              else
 +                      break;
 +      int rc = pclose(fp);
 +      if ( rc == -1 || WEXITSTATUS(rc) )
 +              return NULL;
 +      buf[i] = '\0';
 +      if ( get_sha1(buf, sha1) != 0 )
 +              return NULL;
 +      return lookup_tree(sha1);
 +}
 +
 +/*
 + * TODO: get rid of files_and_dirs; we do not use it except for
 + * current_file_set and current_dir_set, which are global already.
 + */
 +static struct
 +{
 +      struct path_list *files;
 +      struct path_list *dirs;
 +} files_and_dirs;
 +
 +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, files_and_dirs.dirs);
 +      else
 +              path_list_insert(newpath, files_and_dirs.files);
 +      free(newpath);
 +
 +      return READ_TREE_RECURSIVE;
 +}
 +
 +static int get_files_dirs(struct tree *tree,
 +                        struct path_list *files,
 +                        struct path_list *dirs)
 +{
 +      int n;
 +      files_and_dirs.files = files;
 +      files_and_dirs.dirs = dirs;
 +      debug("get_files_dirs ...\n");
 +      if (read_tree_recursive(tree, "", 0, 0, NULL, save_files_dirs) != 0) {
 +              debug("  get_files_dirs done (0)\n");
 +              return 0;
 +      }
 +      n = files->nr + dirs->nr;
 +      debug("  get_files_dirs done (%d)\n", n);
 +      return n;
 +}
 +
 +/*
 + * TODO: this wrapper is so small, we can use path_list_lookup directly.
 + * Same goes for index_entry_get(), free_index_entries(), find_rename_bysrc(),
 + * free_rename_entries().
 + */
 +static struct stage_data *index_entry_find(struct path_list *ents,
 +                                          const char *path)
 +{
 +      struct path_list_item *item = path_list_lookup(path, ents);
 +      if (item)
 +              return item->util;
 +      return NULL;
 +}
 +
 +static struct stage_data *index_entry_get(struct path_list *ents,
 +                                         const char *path)
 +{
 +      struct path_list_item *item = path_list_lookup(path, ents);
 +
 +      if (item == NULL) {
 +              item = path_list_insert(path, ents);
 +              item->util = xcalloc(1, sizeof(struct stage_data));
 +      }
 +      return item->util;
 +}
 +
 +/*
 + * TODO: since the result of index_entry_from_db() is tucked into a
 + * path_list anyway, this helper can do that already.
 + */
 +/*
 + * Returns a index_entry instance which doesn't have to correspond to
 + * a real cache entry in Git's index.
 + */
 +static struct stage_data *index_entry_from_db(const char *path,
 +                                             struct tree *o,
 +                                             struct tree *a,
 +                                             struct tree *b)
 +{
 +      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);
 +      return e;
 +}
 +
 +static void free_index_entries(struct path_list **ents)
 +{
 +      if (!*ents)
 +              return;
 +
 +      path_list_clear(*ents, 1);
 +      free(*ents);
 +      *ents = NULL;
 +}
 +
 +/*
 + * Create a dictionary mapping file names to CacheEntry objects. The
 + * dictionary contains one entry for every path with a non-zero stage entry.
 + */
 +static struct path_list *get_unmerged()
 +{
 +      struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
 +      int i;
 +
 +      unmerged->strdup_paths = 1;
 +      if (!cache_dirty) {
 +              read_cache_from(getenv("GIT_INDEX_FILE"));
 +              cache_dirty++;
 +      }
 +      for (i = 0; i < active_nr; i++) {
 +              struct cache_entry *ce = active_cache[i];
 +              if (!ce_stage(ce))
 +                      continue;
 +
 +              struct stage_data *e = index_entry_get(unmerged, ce->name);
 +              e->stages[ce_stage(ce)].mode = ntohl(ce->ce_mode);
 +              memcpy(e->stages[ce_stage(ce)].sha, ce->sha1, 20);
 +      }
 +
 +      debug("  get_unmerged done\n");
 +      return unmerged;
 +}
 +
 +struct rename
 +{
 +      struct diff_filepair *pair;
 +      struct stage_data *src_entry;
 +      struct stage_data *dst_entry;
 +      unsigned processed:1;
 +};
 +
 +static struct rename *find_rename_bysrc(struct path_list *e,
 +                                            const char *name)
 +{
 +      struct path_list_item *item = path_list_lookup(name, e);
 +      if (item)
 +              return item->util;
 +      return NULL;
 +}
 +
 +static void free_rename_entries(struct path_list **list)
 +{
 +      if (!*list)
 +              return;
 +
 +      path_list_clear(*list, 0);
 +      free(*list);
 +      *list = NULL;
 +}
 +
 +/*
 + * Get information of all renames which occured between 'oTree' and
 + * 'tree'. We need the three trees in the merge ('oTree', 'aTree' and
 + * 'bTree') to be able to associate the correct cache entries with
 + * the rename information. 'tree' is always equal to either aTree or bTree.
 + */
 +static struct path_list *get_renames(struct tree *tree,
 +                                      struct tree *oTree,
 +                                      struct tree *aTree,
 +                                      struct tree *bTree,
 +                                      struct path_list *entries)
 +{
 +#ifdef DEBUG
 +      time_t t = time(0);
 +      debug("getRenames ...\n");
 +#endif
 +      int i;
 +      struct path_list *renames = xcalloc(1, sizeof(struct path_list));
 +      struct diff_options opts;
 +      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(oTree->object.sha1, tree->object.sha1, "", &opts);
 +      diffcore_std(&opts);
 +      for (i = 0; i < diff_queued_diff.nr; ++i) {
 +              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;
 +              re->src_entry = index_entry_find(entries, re->pair->one->path);
 +              /* TODO: should it not be an error, if src_entry was found? */
 +              if ( !re->src_entry ) {
 +                      re->src_entry = index_entry_from_db(re->pair->one->path,
 +                                      oTree, aTree, bTree);
 +                      struct path_list_item *item =
 +                              path_list_insert(re->pair->one->path, entries);
 +                      item->util = re->src_entry;
 +              }
 +              re->dst_entry = index_entry_find(entries, re->pair->two->path);
 +              if ( !re->dst_entry ) {
 +                      re->dst_entry = index_entry_from_db(re->pair->two->path,
 +                                      oTree, aTree, bTree);
 +                      struct path_list_item *item =
 +                              path_list_insert(re->pair->two->path, entries);
 +                      item->util = re->dst_entry;
 +              }
 +              struct path_list_item *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);
 +      debug("  getRenames done in %ld\n", time(0)-t);
 +      return renames;
 +}
 +
 +/*
 + * TODO: the code would be way nicer, if we had a struct containing just sha1 and mode.
 + * In this particular case, we might get away reusing stage_data, no?
 + */
 +int update_stages(const char *path,
 +                 unsigned char *osha, unsigned omode,
 +                 unsigned char *asha, unsigned amode,
 +                 unsigned char *bsha, unsigned bmode,
 +                 int clear /* =True */)
 +{
 +      int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_OK_TO_REPLACE;
 +      if ( clear )
 +              if (add_cacheinfo(0, null_sha1, path, 0, 0, options))
 +                      return -1;
 +      if ( omode )
 +              if (add_cacheinfo(omode, osha, path, 1, 0, options))
 +                      return -1;
 +      if ( amode )
 +              if (add_cacheinfo(omode, osha, path, 2, 0, options))
 +                      return -1;
 +      if ( bmode )
 +              if (add_cacheinfo(omode, osha, path, 3, 0, options))
 +                      return -1;
 +      return 0;
 +}
 +
 +/*
 + * TODO: there has to be a function in libgit doing this exact thing.
 + */
 +static int remove_path(const char *name)
 +{
 +      int ret;
 +      char *slash;
 +
 +      ret = unlink(name);
 +      if ( ret )
 +              return ret;
 +      int len = strlen(name);
 +      char *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;
 +}
 +
 +/* General TODO: unC99ify the code: no declaration after code */
 +/* General TODO: no javaIfiCation: rename updateCache to update_cache */
 +/*
 + * TODO: once we no longer call external programs, we'd probably be better of
 + * not setting / getting the environment variable GIT_INDEX_FILE all the time.
 + */
 +int remove_file(int clean, const char *path)
 +{
 +      int updateCache = index_only || clean;
 +      int updateWd = !index_only;
 +
 +      if ( updateCache ) {
 +              if (!cache_dirty)
 +                      read_cache_from(getenv("GIT_INDEX_FILE"));
 +              cache_dirty++;
 +              if (remove_file_from_cache(path))
 +                      return -1;
 +      }
 +      if ( updateWd )
 +      {
 +              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);
 +      strcpy(newpath, path);
 +      strcat(newpath, "~");
 +      char *p = newpath + strlen(newpath);
 +      strcpy(p, branch);
 +      for ( ; *p; ++p )
 +              if ( '/' == *p )
 +                      *p = '_';
 +      int suffix = 0;
 +      struct stat st;
 +      while ( path_list_has_path(&currentFileSet, newpath) ||
 +              path_list_has_path(&currentDirectorySet, newpath) ||
 +              lstat(newpath, &st) == 0 ) {
 +              sprintf(p, "_%d", suffix++);
 +      }
 +      path_list_insert(newpath, &currentFileSet);
 +      return newpath;
 +}
 +
 +/*
 + * TODO: except for create_last, this so looks like
 + * safe_create_leading_directories().
 + */
 +static int mkdir_p(const char *path, unsigned long mode, int create_last)
 +{
 +      char *buf = strdup(path);
 +      char *p;
 +
 +      for ( p = buf; *p; ++p ) {
 +              if ( *p != '/' )
 +                      continue;
 +              *p = '\0';
 +              if (mkdir(buf, mode)) {
 +                      int e = errno;
 +                      if ( e == EEXIST ) {
 +                              struct stat st;
 +                              if ( !stat(buf, &st) && S_ISDIR(st.st_mode) )
 +                                      goto next; /* ok */
 +                              errno = e;
 +                      }
 +                      free(buf);
 +                      return -1;
 +              }
 +      next:
 +              *p = '/';
 +      }
 +      free(buf);
 +      if ( create_last && mkdir(path, mode) )
 +              return -1;
 +      return 0;
 +}
 +
 +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;
 +      }
 +}
 +
 +/* General TODO: reindent according to guide lines (no if ( blabla )) */
 +void update_file_flags(const unsigned char *sha,
 +                 unsigned mode,
 +                 const char *path,
 +                 int updateCache,
 +                 int updateWd)
 +{
 +      if ( index_only )
 +              updateWd = 0;
 +
 +      if ( updateWd ) {
 +              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) ) {
 +                      if ( mkdir_p(path, 0777, 0 /* don't create last element */) )
 +                              die("failed to create path %s: %s", path, strerror(errno));
 +                      unlink(path);
 +                      if ( mode & 0100 )
 +                              mode = 0777;
 +                      else
 +                              mode = 0666;
 +                      int 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 *linkTarget = malloc(size + 1);
 +                      memcpy(linkTarget, buf, size);
 +                      linkTarget[size] = '\0';
 +                      mkdir_p(path, 0777, 0);
 +                      symlink(linkTarget, path);
 +              } else
 +                      die("do not know what to do with %06o %s '%s'",
 +                          mode, sha1_to_hex(sha), path);
 +      }
 +      if ( updateCache )
 +              add_cacheinfo(mode, sha, path, 0, updateWd, ADD_CACHE_OK_TO_ADD);
 +}
 +
 +/* TODO: is this often used? if not, do direct call */
 +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;
 +}
 +
 +/*
 + * TODO: the signature would be much more efficient using stage_data
 + */
 +static struct merge_file_info merge_file(const char *oPath,
 +                                       const unsigned char *oSha,
 +                                       unsigned oMode,
 +                                       const char *aPath,
 +                                       const unsigned char *aSha,
 +                                       unsigned aMode,
 +                                       const char *bPath,
 +                                       const unsigned char *bSha,
 +                                       unsigned bMode,
 +                                       const char *branch1Name,
 +                                       const char *branch2Name)
 +{
 +      struct merge_file_info result;
 +      result.merge = 0;
 +      result.clean = 1;
 +
 +      if ( (S_IFMT & aMode) != (S_IFMT & bMode) ) {
 +              result.clean = 0;
 +              if ( S_ISREG(aMode) ) {
 +                      result.mode = aMode;
 +                      memcpy(result.sha, aSha, 20);
 +              } else {
 +                      result.mode = bMode;
 +                      memcpy(result.sha, bSha, 20);
 +              }
 +      } else {
 +              if ( memcmp(aSha, oSha, 20) != 0 && memcmp(bSha, oSha, 20) != 0 )
 +                      result.merge = 1;
 +
 +              result.mode = aMode == oMode ? bMode: aMode;
 +
 +              if ( memcmp(aSha, oSha, 20) == 0 )
 +                      memcpy(result.sha, bSha, 20);
 +              else if ( memcmp(bSha, oSha, 20) == 0 )
 +                      memcpy(result.sha, aSha, 20);
 +              else if ( S_ISREG(aMode) ) {
 +
 +                      int code = 1;
 +                      char orig[PATH_MAX];
 +                      char src1[PATH_MAX];
 +                      char src2[PATH_MAX];
 +
 +                      git_unpack_file(oSha, orig);
 +                      git_unpack_file(aSha, src1);
 +                      git_unpack_file(bSha, src2);
 +
 +                      const char *argv[] = {
 +                              "merge", "-L", NULL, "-L", NULL, "-L", NULL,
 +                              src1, orig, src2,
 +                              NULL
 +                      };
 +                      char *la, *lb, *lo;
 +                      argv[2] = la = strdup(mkpath("%s/%s", branch1Name, aPath));
 +                      argv[6] = lb = strdup(mkpath("%s/%s", branch2Name, bPath));
 +                      argv[4] = lo = strdup(mkpath("orig/%s", oPath));
 +
 +#if 0
 +                      printf("%s %s %s %s %s %s %s %s %s %s\n",
 +                             argv[0], argv[1], argv[2], argv[3], argv[4],
 +                             argv[5], argv[6], argv[7], argv[8], argv[9]);
 +#endif
 +                      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?");
 +                      }
 +                      struct stat st;
 +                      int 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);
 +                      close(fd);
 +
 +                      unlink(orig);
 +                      unlink(src1);
 +                      unlink(src2);
 +
 +                      result.clean = WEXITSTATUS(code) == 0;
 +              } else {
 +                      if ( !(S_ISLNK(aMode) || S_ISLNK(bMode)) )
 +                              die("cannot merge modes?");
 +
 +                      memcpy(result.sha, aSha, 20);
 +
 +                      if ( memcmp(aSha, bSha, 20) != 0 )
 +                              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 *dstName1 = ren1_dst;
 +      const char *dstName2 = ren2_dst;
 +      if (path_list_has_path(&currentDirectorySet, ren1_dst)) {
 +              dstName1 = del[delp++] = unique_path(ren1_dst, branch1);
 +              output("%s is a directory in %s adding as %s instead",
 +                     ren1_dst, branch2, dstName1);
 +              remove_file(0, ren1_dst);
 +      }
 +      if (path_list_has_path(&currentDirectorySet, ren2_dst)) {
 +              dstName2 = del[delp++] = unique_path(ren2_dst, branch2);
 +              output("%s is a directory in %s adding as %s instead",
 +                     ren2_dst, branch1, dstName2);
 +              remove_file(0, ren2_dst);
 +      }
 +      update_stages(dstName1,
 +                    NULL, 0,
 +                    ren1->pair->two->sha1, ren1->pair->two->mode,
 +                    NULL, 0,
 +                    1 /* clear */);
 +      update_stages(dstName2,
 +                    NULL, 0,
 +                    NULL, 0,
 +                    ren2->pair->two->sha1, ren2->pair->two->mode,
 +                    1 /* clear */);
 +      while ( delp-- )
 +              free(del[delp]);
 +}
 +
 +static void conflict_rename_dir(struct rename *ren1,
 +                              const char *branch1)
 +{
 +      char *newPath = unique_path(ren1->pair->two->path, branch1);
 +      output("Renaming %s to %s instead", ren1->pair->one->path, newPath);
 +      remove_file(0, ren1->pair->two->path);
 +      update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, newPath);
 +      free(newPath);
 +}
 +
 +static void conflict_rename_rename_2(struct rename *ren1,
 +                                   const char *branch1,
 +                                   struct rename *ren2,
 +                                   const char *branch2)
 +{
 +      char *newPath1 = unique_path(ren1->pair->two->path, branch1);
 +      char *newPath2 = unique_path(ren2->pair->two->path, branch2);
 +      output("Renaming %s to %s and %s to %s instead",
 +             ren1->pair->one->path, newPath1,
 +             ren2->pair->one->path, newPath2);
 +      remove_file(0, ren1->pair->two->path);
 +      update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, newPath1);
 +      update_file(0, ren2->pair->two->sha1, ren2->pair->two->mode, newPath2);
 +      free(newPath2);
 +      free(newPath1);
 +}
 +
 +/* General TODO: get rid of all the debug messages */
 +static int process_renames(struct path_list *renamesA,
 +                         struct path_list *renamesB,
 +                         const char *branchNameA,
 +                         const char *branchNameB)
 +{
 +      int cleanMerge = 1, i;
 +      struct path_list srcNames = {NULL, 0, 0, 0}, byDstA = {NULL, 0, 0, 0}, byDstB = {NULL, 0, 0, 0};
 +      const struct rename *sre;
 +
 +      /*
 +       * TODO: think about a saner way to do this.
 +       * Since both renamesA and renamesB are sorted, it should
 +       * be much more efficient to traverse both simultaneously,
 +       * only byDstA and byDstB should be needed.
 +       */
 +      debug("processRenames...\n");
 +      for (i = 0; i < renamesA->nr; i++) {
 +              sre = renamesA->items[i].util;
 +              path_list_insert(sre->pair->one->path, &srcNames);
 +              path_list_insert(sre->pair->two->path, &byDstA)->util
 +                      = sre->dst_entry;
 +      }
 +      for (i = 0; i < renamesB->nr; i++) {
 +              sre = renamesB->items[i].util;
 +              path_list_insert(sre->pair->one->path, &srcNames);
 +              path_list_insert(sre->pair->two->path, &byDstB)->util
 +                      = sre->dst_entry;
 +      }
 +
 +      for (i = 0; i < srcNames.nr; i++) {
 +              char *src = srcNames.items[i].path;
 +              struct path_list *renames1, *renames2, *renames2Dst;
 +              struct rename *ren1, *ren2;
 +              const char *branchName1, *branchName2;
 +              ren1 = find_rename_bysrc(renamesA, src);
 +              ren2 = find_rename_bysrc(renamesB, src);
 +              /* TODO: refactor, so that 1/2 are not needed */
 +              if ( ren1 ) {
 +                      renames1 = renamesA;
 +                      renames2 = renamesB;
 +                      renames2Dst = &byDstB;
 +                      branchName1 = branchNameA;
 +                      branchName2 = branchNameB;
 +              } else {
 +                      renames1 = renamesB;
 +                      renames2 = renamesA;
 +                      renames2Dst = &byDstA;
 +                      branchName1 = branchNameB;
 +                      branchName2 = branchNameA;
 +                      struct rename *tmp = ren2;
 +                      ren2 = ren1;
 +                      ren1 = tmp;
 +              }
 +
 +              ren1->dst_entry->processed = 1;
 +              ren1->src_entry->processed = 1;
 +
 +              if ( ren1->processed )
 +                      continue;
 +              ren1->processed = 1;
 +
 +              const char *ren1_src = ren1->pair->one->path;
 +              const char *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) {
 +                              cleanMerge = 0;
 +                              output("CONFLICT (rename/rename): "
 +                                     "Rename %s->%s in branch %s "
 +                                     "rename %s->%s in %s",
 +                                     src, ren1_dst, branchName1,
 +                                     src, ren2_dst, branchName2);
 +                              conflict_rename_rename(ren1, branchName1, ren2, branchName2);
 +                      } else {
 +                              remove_file(1, ren1_src);
 +                              struct merge_file_info mfi;
 +                              mfi = merge_file(ren1_src,
 +                                               ren1->pair->one->sha1,
 +                                               ren1->pair->one->mode,
 +                                               ren1_dst,
 +                                               ren1->pair->two->sha1,
 +                                               ren1->pair->two->mode,
 +                                               ren2_dst,
 +                                               ren2->pair->two->sha1,
 +                                               ren2->pair->two->mode,
 +                                               branchName1,
 +                                               branchName2);
 +                              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);
 +                                      cleanMerge = 0;
 +
 +                                      if ( !index_only )
 +                                              update_stages(ren1_dst,
 +                                                            ren1->pair->one->sha1,
 +                                                            ren1->pair->one->mode,
 +                                                            ren1->pair->two->sha1,
 +                                                            ren1->pair->two->mode,
 +                                                            ren2->pair->two->sha1,
 +                                                            ren2->pair->two->mode,
 +                                                            1 /* clear */);
 +                              }
 +                              update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 +                      }
 +              } else {
 +                      /* Renamed in 1, maybe changed in 2 */
 +                      remove_file(1, ren1_src);
 +
 +                      unsigned char srcShaOtherBranch[20], dstShaOtherBranch[20];
 +                      unsigned srcModeOtherBranch, dstModeOtherBranch;
 +
 +                      int stage = renamesA == renames1 ? 3: 2;
 +
 +                      memcpy(srcShaOtherBranch, ren1->src_entry->stages[stage].sha, 20);
 +                      srcModeOtherBranch = ren1->src_entry->stages[stage].mode;
 +
 +                      memcpy(dstShaOtherBranch, ren1->dst_entry->stages[stage].sha, 20);
 +                      dstModeOtherBranch = ren1->dst_entry->stages[stage].mode;
 +
 +                      int tryMerge = 0;
 +                      char *newPath;
 +
 +                      if (path_list_has_path(&currentDirectorySet, ren1_dst)) {
 +                              cleanMerge = 0;
 +                              output("CONFLICT (rename/directory): Rename %s->%s in %s "
 +                                     " directory %s added in %s",
 +                                     ren1_src, ren1_dst, branchName1,
 +                                     ren1_dst, branchName2);
 +                              conflict_rename_dir(ren1, branchName1);
 +                      } else if ( memcmp(srcShaOtherBranch, null_sha1, 20) == 0 ) {
 +                              cleanMerge = 0;
 +                              output("CONFLICT (rename/delete): Rename %s->%s in %s "
 +                                     "and deleted in %s",
 +                                     ren1_src, ren1_dst, branchName1,
 +                                     branchName2);
 +                              update_file(0, ren1->pair->two->sha1, ren1->pair->two->mode, ren1_dst);
 +                      } else if ( memcmp(dstShaOtherBranch, null_sha1, 20) != 0 ) {
 +                              cleanMerge = 0;
 +                              tryMerge = 1;
 +                              output("CONFLICT (rename/add): Rename %s->%s in %s. "
 +                                     "%s added in %s",
 +                                     ren1_src, ren1_dst, branchName1,
 +                                     ren1_dst, branchName2);
 +                              newPath = unique_path(ren1_dst, branchName2);
 +                              output("Adding as %s instead", newPath);
 +                              update_file(0, dstShaOtherBranch, dstModeOtherBranch, newPath);
 +                      } else if ( (ren2 = find_rename_bysrc(renames2Dst, ren1_dst)) ) {
 +                              cleanMerge = 0;
 +                              ren2->processed = 1;
 +                              output("CONFLICT (rename/rename): Rename %s->%s in %s. "
 +                                     "Rename %s->%s in %s",
 +                                     ren1_src, ren1_dst, branchName1,
 +                                     ren2->pair->one->path, ren2->pair->two->path, branchName2);
 +                              conflict_rename_rename_2(ren1, branchName1, ren2, branchName2);
 +                      } else
 +                              tryMerge = 1;
 +
 +                      if ( tryMerge ) {
 +                              const char *oname = ren1_src;
 +                              const char *aname = ren1_dst;
 +                              const char *bname = ren1_src;
 +                              unsigned char osha[20], asha[20], bsha[20];
 +                              unsigned omode = ren1->pair->one->mode;
 +                              unsigned amode = ren1->pair->two->mode;
 +                              unsigned bmode = srcModeOtherBranch;
 +                              memcpy(osha, ren1->pair->one->sha1, 20);
 +                              memcpy(asha, ren1->pair->two->sha1, 20);
 +                              memcpy(bsha, srcShaOtherBranch, 20);
 +                              const char *aBranch = branchName1;
 +                              const char *bBranch = branchName2;
 +
 +                              if ( renamesA != renames1 ) {
 +                                      memswp(&aname, &bname, sizeof(aname));
 +                                      memswp(asha, bsha, 20);
 +                                      memswp(&aBranch, &bBranch, sizeof(aBranch));
 +                              }
 +                              struct merge_file_info mfi;
 +                              mfi = merge_file(oname, osha, omode,
 +                                               aname, asha, amode,
 +                                               bname, bsha, bmode,
 +                                               aBranch, bBranch);
 +
 +                              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);
 +                                      cleanMerge = 0;
 +
 +                                      if ( !index_only )
 +                                              update_stages(ren1_dst,
 +                                                            osha, omode,
 +                                                            asha, amode,
 +                                                            bsha, bmode,
 +                                                            1 /* clear */);
 +                              }
 +                              update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
 +                      }
 +              }
 +      }
 +      path_list_clear(&srcNames, 0);
 +      debug("  processRenames done\n");
 +
 +      if (cache_dirty)
 +              flush_cache();
 +      return cleanMerge;
 +}
 +
 +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 *branch1Name,
 +                       const char *branch2Name)
 +{
 +      /*
 +      printf("processing entry, clean cache: %s\n", index_only ? "yes": "no");
 +      print_index_entry("\tpath: ", entry);
 +      */
 +      int cleanMerge = 1;
 +      unsigned char *oSha = has_sha(entry->stages[1].sha);
 +      unsigned char *aSha = has_sha(entry->stages[2].sha);
 +      unsigned char *bSha = has_sha(entry->stages[3].sha);
 +      unsigned oMode = entry->stages[1].mode;
 +      unsigned aMode = entry->stages[2].mode;
 +      unsigned bMode = entry->stages[3].mode;
 +
 +      if ( oSha && (!aSha || !bSha) ) {
 +              /* Case A: Deleted in one */
 +              if ( (!aSha && !bSha) ||
 +                   (sha_eq(aSha, oSha) && !bSha) ||
 +                   (!aSha && sha_eq(bSha, oSha)) ) {
 +                      /* Deleted in both or deleted in one and
 +                       * unchanged in the other */
 +                      if ( aSha )
 +                              output("Removing %s", path);
 +                      remove_file(1, path);
 +              } else {
 +                      /* Deleted in one and changed in the other */
 +                      cleanMerge = 0;
 +                      if ( !aSha ) {
 +                              output("CONFLICT (delete/modify): %s deleted in %s "
 +                                     "and modified in %s. Version %s of %s left in tree.",
 +                                     path, branch1Name,
 +                                     branch2Name, branch2Name, path);
 +                              update_file(0, bSha, bMode, path);
 +                      } else {
 +                              output("CONFLICT (delete/modify): %s deleted in %s "
 +                                     "and modified in %s. Version %s of %s left in tree.",
 +                                     path, branch2Name,
 +                                     branch1Name, branch1Name, path);
 +                              update_file(0, aSha, aMode, path);
 +                      }
 +              }
 +
 +      } else if ( (!oSha && aSha && !bSha) ||
 +                  (!oSha && !aSha && bSha) ) {
 +              /* Case B: Added in one. */
 +              const char *addBranch;
 +              const char *otherBranch;
 +              unsigned mode;
 +              const unsigned char *sha;
 +              const char *conf;
 +
 +              if ( aSha ) {
 +                      addBranch = branch1Name;
 +                      otherBranch = branch2Name;
 +                      mode = aMode;
 +                      sha = aSha;
 +                      conf = "file/directory";
 +              } else {
 +                      addBranch = branch2Name;
 +                      otherBranch = branch1Name;
 +                      mode = bMode;
 +                      sha = bSha;
 +                      conf = "directory/file";
 +              }
 +              if ( path_list_has_path(&currentDirectorySet, path) ) {
 +                      cleanMerge = 0;
 +                      const char *newPath = unique_path(path, addBranch);
 +                      output("CONFLICT (%s): There is a directory with name %s in %s. "
 +                             "Adding %s as %s",
 +                             conf, path, otherBranch, path, newPath);
 +                      remove_file(0, path);
 +                      update_file(0, sha, mode, newPath);
 +              } else {
 +                      output("Adding %s", path);
 +                      update_file(1, sha, mode, path);
 +              }
 +      } else if ( !oSha && aSha && bSha ) {
 +              /* Case C: Added in both (check for same permissions). */
 +              if ( sha_eq(aSha, bSha) ) {
 +                      if ( aMode != bMode ) {
 +                              cleanMerge = 0;
 +                              output("CONFLICT: File %s added identically in both branches, "
 +                                     "but permissions conflict %06o->%06o",
 +                                     path, aMode, bMode);
 +                              output("CONFLICT: adding with permission: %06o", aMode);
 +                              update_file(0, aSha, aMode, path);
 +                      } else {
 +                              /* This case is handled by git-read-tree */
 +                              assert(0 && "This case must be handled by git-read-tree");
 +                      }
 +              } else {
 +                      cleanMerge = 0;
 +                      const char *newPath1 = unique_path(path, branch1Name);
 +                      const char *newPath2 = unique_path(path, branch2Name);
 +                      output("CONFLICT (add/add): File %s added non-identically "
 +                             "in both branches. Adding as %s and %s instead.",
 +                             path, newPath1, newPath2);
 +                      remove_file(0, path);
 +                      update_file(0, aSha, aMode, newPath1);
 +                      update_file(0, bSha, bMode, newPath2);
 +              }
 +
 +      } else if ( oSha && aSha && bSha ) {
 +              /* case D: Modified in both, but differently. */
 +              output("Auto-merging %s", path);
 +              struct merge_file_info mfi;
 +              mfi = merge_file(path, oSha, oMode,
 +                               path, aSha, aMode,
 +                               path, bSha, bMode,
 +                               branch1Name, branch2Name);
 +
 +              if ( mfi.clean )
 +                      update_file(1, mfi.sha, mfi.mode, path);
 +              else {
 +                      cleanMerge = 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 /* updateCache */, 1 /* updateWd */);
 +              }
 +      } else
 +              die("Fatal merge failure, shouldn't happen.");
 +
 +      if (cache_dirty)
 +              flush_cache();
 +
 +      return cleanMerge;
 +}
 +
 +static struct merge_tree_result merge_trees(struct tree *head,
 +                                          struct tree *merge,
 +                                          struct tree *common,
 +                                          const char *branch1Name,
 +                                          const char *branch2Name)
 +{
 +      int code;
 +      struct merge_tree_result result = { NULL, 0 };
 +      if ( !memcmp(common->object.sha1, merge->object.sha1, 20) ) {
 +              output("Already uptodate!");
 +              result.tree = head;
 +              result.clean = 1;
 +              return result;
 +      }
 +
 +      debug("merge_trees ...\n");
 +      code = git_merge_trees(index_only ? "-i": "-u", 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.tree = git_write_tree();
 +
 +      if ( !result.tree ) {
 +              path_list_clear(&currentFileSet, 1);
 +              path_list_clear(&currentDirectorySet, 1);
 +              get_files_dirs(head, &currentFileSet, &currentDirectorySet);
 +              get_files_dirs(merge, &currentFileSet, &currentDirectorySet);
 +
 +              struct path_list *entries = get_unmerged();
 +              struct path_list *re_head, *re_merge;
 +              re_head  = get_renames(head, common, head, merge, entries);
 +              re_merge = get_renames(merge, common, head, merge, entries);
 +              result.clean = process_renames(re_head, re_merge,
 +                                             branch1Name, branch2Name);
 +              debug("\tprocessing entries...\n");
 +              int i;
 +              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, branch1Name, branch2Name))
 +                              result.clean = 0;
 +              }
 +
 +              free_rename_entries(&re_merge);
 +              free_rename_entries(&re_head);
 +              free_index_entries(&entries);
 +
 +              if (result.clean || index_only)
 +                      result.tree = git_write_tree();
 +              else
 +                      result.tree = NULL;
 +              debug("\t  processing entries done\n");
 +      } else {
 +              result.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.tree->object.sha1));
 +      }
 +
 +      debug("  merge_trees done\n");
 +      return result;
 +}
 +
 +/*
 + * Merge the commits h1 and h2, return the resulting virtual
 + * commit object and a flag indicating the cleaness of the merge.
 + */
 +static
 +struct merge_result merge(struct commit *h1,
 +                        struct commit *h2,
 +                        const char *branch1Name,
 +                        const char *branch2Name,
 +                        int callDepth /* =0 */,
 +                        struct commit *ancestor /* =None */)
 +{
 +      struct merge_result result = { NULL, 0 };
 +      const char *msg;
 +      int msglen;
 +      struct commit_list *ca = NULL, *iter;
 +      struct commit *mergedCA;
 +      struct merge_tree_result mtr;
 +
 +      output("Merging:");
 +      msg = commit_title(h1, &msglen);
 +      /* TODO: refactor. we always show the sha1 with the title */
 +      output("%s %.*s", commit_hex_sha1(h1), msglen, msg);
 +      msg = commit_title(h2, &msglen);
 +      output("%s %.*s", commit_hex_sha1(h2), msglen, msg);
 +
 +      if ( ancestor )
 +              commit_list_insert(ancestor, &ca);
 +      else
 +              ca = get_merge_bases(h1, h2, 1);
 +
 +      output("found %u common ancestor(s):", commit_list_count(ca));
 +      for (iter = ca; iter; iter = iter->next) {
 +              msg = commit_title(iter->item, &msglen);
 +              output("%s %.*s", commit_hex_sha1(iter->item), msglen, msg);
 +      }
 +
 +      mergedCA = pop_commit(&ca);
 +
 +      /* TODO: what happens when merge with virtual commits fails? */
 +      for (iter = ca; iter; iter = iter->next) {
 +              output_indent = callDepth + 1;
 +              result = merge(mergedCA, iter->item,
 +                             "Temporary merge branch 1",
 +                             "Temporary merge branch 2",
 +                             callDepth + 1,
 +                             NULL);
 +              mergedCA = result.commit;
 +              output_indent = callDepth;
 +
 +              if ( !mergedCA )
 +                      die("merge returned no commit");
 +      }
 +
 +      if ( callDepth == 0 ) {
 +              setup_index(0);
 +              index_only = 0;
 +      } else {
 +              setup_index(1);
 +              git_read_tree(h1->tree);
 +              index_only = 1;
 +      }
 +
 +      mtr = merge_trees(h1->tree, h2->tree,
 +                        mergedCA->tree, branch1Name, branch2Name);
 +
 +      if ( !ancestor && (mtr.clean || index_only) ) {
 +              result.commit = make_virtual_commit(mtr.tree, "merged tree");
 +              commit_list_insert(h1, &result.commit->parents);
 +              commit_list_insert(h2, &result.commit->parents->next);
 +      } else
 +              result.commit = NULL;
 +
 +      result.clean = mtr.clean;
 +      return result;
 +}
 +
 +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;
 +
 +      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]);
 +
 +      int i;
 +      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.");
 +
 +      const char *branch1, *branch2;
 +
 +      branch1 = argv[++i];
 +      branch2 = argv[++i];
 +      printf("Merging %s with %s\n", branch1, branch2);
 +
 +      struct merge_result result;
 +      struct commit *h1 = get_ref(branch1);
 +      struct commit *h2 = get_ref(branch2);
 +
 +      if (bases_count == 1) {
 +              struct commit *ancestor = get_ref(bases[0]);
 +              result = merge(h1, h2, branch1, branch2, 0, ancestor);
 +      } else
 +              result = merge(h1, h2, branch1, branch2, 0, NULL);
 +
 +      if (cache_dirty)
 +              flush_cache();
 +
 +      return result.clean ? 0: 1;
 +}
 +
 +/*
 +vim: sw=8 noet
 +*/
diff --cc upload-pack.c
Simple merge