Cumulative update of merge-recursive in C
[gitweb.git] / merge-recursive.c
index 8d30519db177dd63ee360d6d08fb58d70a42a834..d78f58d8d2463c49bf14d3639ec60772b232f7f9 100644 (file)
@@ -25,9 +25,9 @@
 /*#define DEBUG*/
 
 #ifdef DEBUG
-#define debug(args, ...) fprintf(stderr, args, ## __VA_ARGS__)
+#define debug(...) fprintf(stderr, __VA_ARGS__)
 #else
-#define debug(args, ...)
+#define debug(...) do { ; /* nothing */ } while (0)
 #endif
 
 #ifdef DEBUG
@@ -61,13 +61,14 @@ static void show_ce_entry(const char *tag, struct cache_entry *ce)
        fputc('\n', stderr);
 }
 
-static void ls_files() {
+static void ls_files(void) {
        int i;
        for (i = 0; i < active_nr; i++) {
                struct cache_entry *ce = active_cache[i];
                show_ce_entry("", ce);
        }
        fprintf(stderr, "---\n");
+       if (0) ls_files(); /* avoid "unused" warning */
 }
 #endif
 
@@ -76,41 +77,6 @@ static void ls_files() {
  * - (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)
 {
@@ -136,41 +102,11 @@ static struct commit *make_virtual_commit(struct tree *tree, const char *comment
  */
 static int sha_eq(const unsigned char *a, const unsigned char *b)
 {
-       if ( !a && !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).
@@ -195,7 +131,7 @@ static void output(const char *fmt, ...)
 {
        va_list args;
        int i;
-       for ( i = output_indent; i--; )
+       for (i = output_indent; i--;)
                fputs("  ", stdout);
        va_start(args, fmt);
        vfprintf(stdout, fmt, args);
@@ -203,11 +139,37 @@ static void output(const char *fmt, ...)
        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 *original_index_file;
 static const char *temporary_index_file;
 static int cache_dirty = 0;
 
-static int flush_cache()
+static int flush_cache(void)
 {
        /* flush temporary index */
        struct lock_file *lock = xcalloc(1, sizeof(struct lock_file));
@@ -290,11 +252,12 @@ static int git_read_tree(const struct tree *tree)
                getenv("GIT_INDEX_FILE"),
                sha1_to_hex(tree->object.sha1));
 #endif
+       int rc;
        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);
+       rc = run_command_v(2, argv);
        return rc < 0 ? -1: rc;
 }
 
@@ -314,6 +277,7 @@ static int git_merge_trees(const char *update_arg,
                sha1_to_hex(head->object.sha1),
                sha1_to_hex(merge->object.sha1));
 #endif
+       int rc;
        const char *argv[] = {
                "git-read-tree", NULL, "-m", NULL, NULL, NULL,
                NULL,
@@ -324,50 +288,42 @@ static int git_merge_trees(const char *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);
+       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()
+static struct tree *git_write_tree(void)
 {
 #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");
+       FILE *fp;
+       int rc;
        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' )
+       if (cache_dirty)
+               flush_cache();
+       fp = popen("git-write-tree 2>/dev/null", "r");
+       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) )
+       rc = pclose(fp);
+       if (rc == -1 || WEXITSTATUS(rc))
                return NULL;
        buf[i] = '\0';
-       if ( get_sha1(buf, sha1) != 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)
@@ -379,70 +335,36 @@ static int save_files_dirs(const unsigned char *sha1,
        newpath[baselen + len] = '\0';
 
        if (S_ISDIR(mode))
-               path_list_insert(newpath, files_and_dirs.dirs);
+               path_list_insert(newpath, &currentDirectorySet);
        else
-               path_list_insert(newpath, files_and_dirs.files);
+               path_list_insert(newpath, &currentFileSet);
        free(newpath);
 
        return READ_TREE_RECURSIVE;
 }
 
-static int get_files_dirs(struct tree *tree,
-                         struct path_list *files,
-                         struct path_list *dirs)
+static int get_files_dirs(struct tree *tree)
 {
        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;
+       n = currentFileSet.nr + currentDirectorySet.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)
+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);
@@ -450,24 +372,16 @@ static struct stage_data *index_entry_from_db(const char *path,
                        e->stages[2].sha, &e->stages[2].mode);
        get_tree_entry(b->object.sha1, path,
                        e->stages[3].sha, &e->stages[3].mode);
+       item = path_list_insert(path, entries);
+       item->util = e;
        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()
+static struct path_list *get_unmerged(void)
 {
        struct path_list *unmerged = xcalloc(1, sizeof(struct path_list));
        int i;
@@ -478,16 +392,22 @@ static struct path_list *get_unmerged()
                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;
 
-               struct stage_data *e = index_entry_get(unmerged, ce->name);
+               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);
        }
 
-       debug("  get_unmerged done\n");
        return unmerged;
 }
 
@@ -499,25 +419,6 @@ struct rename
        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
@@ -530,13 +431,16 @@ static struct path_list *get_renames(struct tree *tree,
                                        struct tree *bTree,
                                        struct path_list *entries)
 {
+       int i;
+       struct path_list *renames;
+       struct diff_options opts;
 #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;
+
+       renames = xcalloc(1, sizeof(struct path_list));
        diff_setup(&opts);
        opts.recursive = 1;
        opts.detect_rename = DIFF_DETECT_RENAME;
@@ -546,6 +450,7 @@ static struct path_list *get_renames(struct tree *tree,
        diff_tree_sha1(oTree->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') {
@@ -555,78 +460,66 @@ static struct path_list *get_renames(struct tree *tree,
                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 = path_list_lookup(re->pair->one->path, entries);
+               if (!item)
+                       re->src_entry = insert_stage_data(re->pair->one->path,
+                                       oTree, aTree, bTree, 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,
+                                       oTree, aTree, bTree, 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);
+#ifdef DEBUG
        debug("  getRenames done in %ld\n", time(0)-t);
+#endif
        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 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 (add_cacheinfo(0, null_sha1, path, 0, 0, options))
+       if (clear)
+               if (remove_file_from_cache(path))
                        return -1;
-       if ( omode )
-               if (add_cacheinfo(omode, osha, path, 1, 0, options))
+       if (o)
+               if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
                        return -1;
-       if ( amode )
-               if (add_cacheinfo(omode, osha, path, 2, 0, options))
+       if (a)
+               if (add_cacheinfo(a->mode, a->sha1, path, 2, 0, options))
                        return -1;
-       if ( bmode )
-               if (add_cacheinfo(omode, osha, path, 3, 0, options))
+       if (b)
+               if (add_cacheinfo(b->mode, b->sha1, 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;
+       int ret, len;
+       char *slash, *dirs;
 
        ret = unlink(name);
-       if ( ret )
+       if (ret)
                return ret;
-       int len = strlen(name);
-       char *dirs = malloc(len+1);
+       len = strlen(name);
+       dirs = malloc(len+1);
        memcpy(dirs, name, len);
        dirs[len] = '\0';
-       while ( (slash = strrchr(name, '/')) ) {
+       while ((slash = strrchr(name, '/'))) {
                *slash = '\0';
                len = slash - name;
-               if ( rmdir(name) != 0 )
+               if (rmdir(name) != 0)
                        break;
        }
        free(dirs);
@@ -636,7 +529,7 @@ static int remove_path(const char *name)
 /* 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
+ * TODO: once we no longer call external programs, we'd probably be better off
  * not setting / getting the environment variable GIT_INDEX_FILE all the time.
  */
 int remove_file(int clean, const char *path)
@@ -644,17 +537,17 @@ int remove_file(int clean, const char *path)
        int updateCache = index_only || clean;
        int updateWd = !index_only;
 
-       if ( updateCache ) {
+       if (updateCache) {
                if (!cache_dirty)
                        read_cache_from(getenv("GIT_INDEX_FILE"));
                cache_dirty++;
                if (remove_file_from_cache(path))
                        return -1;
        }
-       if ( updateWd )
+       if (updateWd)
        {
                unlink(path);
-               if ( errno != ENOENT || errno != EISDIR )
+               if (errno != ENOENT || errno != EISDIR)
                        return -1;
                remove_path(path);
        }
@@ -664,55 +557,31 @@ int remove_file(int clean, const char *path)
 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(newpath);
        strcpy(newpath, path);
        strcat(newpath, "~");
-       char *p = newpath + strlen(newpath);
        strcpy(p, branch);
-       for ( ; *p; ++p )
-               if ( '/' == *p )
+       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 ) {
+       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)
+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);
-       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 = '/';
-       }
+       int result = safe_create_leading_directories(buf);
        free(buf);
-       if ( create_last && mkdir(path, mode) )
-               return -1;
-       return 0;
+       return result;
 }
 
 static void flush_buffer(int fd, const char *buf, unsigned long size)
@@ -732,17 +601,16 @@ static void flush_buffer(int fd, const char *buf, unsigned long size)
        }
 }
 
-/* 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)
+                      unsigned mode,
+                      const char *path,
+                      int update_cache,
+                      int update_wd)
 {
-       if ( index_only )
-               updateWd = 0;
+       if (index_only)
+               update_wd = 0;
 
-       if ( updateWd ) {
+       if (update_wd) {
                char type[20];
                void *buf;
                unsigned long size;
@@ -750,37 +618,38 @@ void update_file_flags(const unsigned char *sha,
                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 )
+               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 */) )
+               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 )
+                       if (mode & 0100)
                                mode = 0777;
                        else
                                mode = 0666;
-                       int fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
-                       if ( fd < 0 )
+                       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 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 ( updateCache )
-               add_cacheinfo(mode, sha, path, 0, updateWd, ADD_CACHE_OK_TO_ADD);
+       if (update_cache)
+               add_cacheinfo(mode, sha, path, 0, update_wd, 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,
@@ -819,64 +688,53 @@ static char *git_unpack_file(const unsigned char *sha1, char *path)
        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)
+static struct merge_file_info merge_file(struct diff_filespec *o,
+               struct diff_filespec *a, struct diff_filespec *b,
+               const char *branch1Name, const char *branch2Name)
 {
        struct merge_file_info result;
        result.merge = 0;
        result.clean = 1;
 
-       if ( (S_IFMT & aMode) != (S_IFMT & bMode) ) {
+       if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
                result.clean = 0;
-               if ( S_ISREG(aMode) ) {
-                       result.mode = aMode;
-                       memcpy(result.sha, aSha, 20);
+               if (S_ISREG(a->mode)) {
+                       result.mode = a->mode;
+                       memcpy(result.sha, a->sha1, 20);
                } else {
-                       result.mode = bMode;
-                       memcpy(result.sha, bSha, 20);
+                       result.mode = b->mode;
+                       memcpy(result.sha, b->sha1, 20);
                }
        } else {
-               if ( memcmp(aSha, oSha, 20) != 0 && memcmp(bSha, oSha, 20) != 0 )
+               if (!sha_eq(a->sha1, o->sha1) && !sha_eq(b->sha1, o->sha1))
                        result.merge = 1;
 
-               result.mode = aMode == oMode ? bMode: aMode;
+               result.mode = a->mode == o->mode ? b->mode: a->mode;
 
-               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;
+               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];
-
-                       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));
+
+                       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", branch1Name, a->path));
+                       argv[6] = lb = strdup(mkpath("%s/%s", branch2Name, b->path));
+                       argv[4] = lo = strdup(mkpath("orig/%s", o->path));
 
 #if 0
                        printf("%s %s %s %s %s %s %s %s %s %s\n",
@@ -888,17 +746,15 @@ static struct merge_file_info merge_file(const char *oPath,
                        free(la);
                        free(lb);
                        free(lo);
-                       if ( code && code < -256 ) {
+                       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);
+                       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);
@@ -906,12 +762,12 @@ static struct merge_file_info merge_file(const char *oPath,
 
                        result.clean = WEXITSTATUS(code) == 0;
                } else {
-                       if ( !(S_ISLNK(aMode) || S_ISLNK(bMode)) )
+                       if (!(S_ISLNK(a->mode) || S_ISLNK(b->mode)))
                                die("cannot merge modes?");
 
-                       memcpy(result.sha, aSha, 20);
+                       memcpy(result.sha, a->sha1, 20);
 
-                       if ( memcmp(aSha, bSha, 20) != 0 )
+                       if (!sha_eq(a->sha1, b->sha1))
                                result.clean = 0;
                }
        }
@@ -942,17 +798,9 @@ static void conflict_rename_rename(struct rename *ren1,
                       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-- )
+       update_stages(dstName1, NULL, ren1->pair->two, NULL, 1);
+       update_stages(dstName2, NULL, NULL, ren2->pair->two, 1);
+       while (delp--)
                free(del[delp]);
 }
 
@@ -989,66 +837,73 @@ static int process_renames(struct path_list *renamesA,
                           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};
+       int cleanMerge = 1, i, j;
+       struct path_list 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;
+       for (i = 0, j = 0; i < renamesA->nr || j < renamesB->nr;) {
+               int compare;
+               char *src;
                struct path_list *renames1, *renames2, *renames2Dst;
-               struct rename *ren1, *ren2;
+               struct rename *ren1 = NULL, *ren2 = NULL;
                const char *branchName1, *branchName2;
-               ren1 = find_rename_bysrc(renamesA, src);
-               ren2 = find_rename_bysrc(renamesB, src);
+               const char *ren1_src, *ren1_dst;
+
+               if (i >= renamesA->nr) {
+                       compare = 1;
+                       ren2 = renamesB->items[j++].util;
+               } else if (j >= renamesB->nr) {
+                       compare = -1;
+                       ren1 = renamesA->items[i++].util;
+               } else {
+                       compare = strcmp(renamesA->items[i].path,
+                                       renamesB->items[j].path);
+                       ren1 = renamesA->items[i++].util;
+                       ren2 = renamesB->items[j++].util;
+               }
+
                /* TODO: refactor, so that 1/2 are not needed */
-               if ( ren1 ) {
+               if (ren1) {
                        renames1 = renamesA;
                        renames2 = renamesB;
                        renames2Dst = &byDstB;
                        branchName1 = branchNameA;
                        branchName2 = branchNameB;
                } else {
+                       struct rename *tmp;
                        renames1 = renamesB;
                        renames2 = renamesA;
                        renames2Dst = &byDstA;
                        branchName1 = branchNameB;
                        branchName2 = branchNameA;
-                       struct rename *tmp = ren2;
+                       tmp = ren2;
                        ren2 = ren1;
                        ren1 = tmp;
                }
+               src = ren1->pair->one->path;
 
                ren1->dst_entry->processed = 1;
                ren1->src_entry->processed = 1;
 
-               if ( ren1->processed )
+               if (ren1->processed)
                        continue;
                ren1->processed = 1;
 
-               const char *ren1_src = ren1->pair->one->path;
-               const char *ren1_dst = ren1->pair->two->path;
+               ren1_src = ren1->pair->one->path;
+               ren1_dst = ren1->pair->two->path;
 
-               if ( ren2 ) {
+               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 */
@@ -1067,57 +922,48 @@ static int process_renames(struct path_list *renamesA,
                        } 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,
+                               mfi = merge_file(ren1->pair->one,
+                                                ren1->pair->two,
+                                                ren2->pair->two,
                                                 branchName1,
                                                 branchName2);
-                               if ( mfi.merge || !mfi.clean )
+                               if (mfi.merge || !mfi.clean)
                                        output("Renaming %s->%s", src, ren1_dst);
 
-                               if ( mfi.merge )
+                               if (mfi.merge)
                                        output("Auto-merging %s", ren1_dst);
 
-                               if ( !mfi.clean ) {
+                               if (!mfi.clean) {
                                        output("CONFLICT (content): merge conflict in %s",
                                               ren1_dst);
                                        cleanMerge = 0;
 
-                                       if ( !index_only )
+                                       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,
+                                                             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 */
-                       remove_file(1, ren1_src);
-
-                       unsigned char srcShaOtherBranch[20], dstShaOtherBranch[20];
-                       unsigned srcModeOtherBranch, dstModeOtherBranch;
+                       struct path_list_item *item;
+                       /* we only use sha1 and mode of these */
+                       struct diff_filespec src_other, dst_other;
+                       int tryMerge, stage = renamesA == renames1 ? 3: 2;
 
-                       int stage = renamesA == renames1 ? 3: 2;
-
-                       memcpy(srcShaOtherBranch, ren1->src_entry->stages[stage].sha, 20);
-                       srcModeOtherBranch = ren1->src_entry->stages[stage].mode;
+                       remove_file(1, ren1_src);
 
-                       memcpy(dstShaOtherBranch, ren1->dst_entry->stages[stage].sha, 20);
-                       dstModeOtherBranch = ren1->dst_entry->stages[stage].mode;
+                       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;
 
-                       int tryMerge = 0;
-                       char *newPath;
+                       tryMerge = 0;
 
                        if (path_list_has_path(&currentDirectorySet, ren1_dst)) {
                                cleanMerge = 0;
@@ -1126,14 +972,15 @@ static int process_renames(struct path_list *renamesA,
                                       ren1_src, ren1_dst, branchName1,
                                       ren1_dst, branchName2);
                                conflict_rename_dir(ren1, branchName1);
-                       } else if ( memcmp(srcShaOtherBranch, null_sha1, 20) == 0 ) {
+                       } else if (sha_eq(src_other.sha1, null_sha1)) {
                                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 ) {
+                       } else if (!sha_eq(dst_other.sha1, null_sha1)) {
+                               const char *newPath;
                                cleanMerge = 0;
                                tryMerge = 1;
                                output("CONFLICT (rename/add): Rename %s->%s in %s. "
@@ -1142,8 +989,9 @@ static int process_renames(struct path_list *renamesA,
                                       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)) ) {
+                               update_file(0, dst_other.sha1, dst_other.mode, newPath);
+                       } else if ((item = path_list_lookup(ren1_dst, renames2Dst))) {
+                               ren2 = item->util;
                                cleanMerge = 0;
                                ren2->processed = 1;
                                output("CONFLICT (rename/rename): Rename %s->%s in %s. "
@@ -1154,53 +1002,41 @@ static int process_renames(struct path_list *renamesA,
                        } 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));
-                               }
+                       if (tryMerge) {
+                               struct diff_filespec *o, *a, *b;
                                struct merge_file_info mfi;
-                               mfi = merge_file(oname, osha, omode,
-                                                aname, asha, amode,
-                                                bname, bsha, bmode,
-                                                aBranch, bBranch);
+                               src_other.path = (char *)ren1_src;
+
+                               o = ren1->pair->one;
+                               if (renamesA == renames1) {
+                                       a = ren1->pair->two;
+                                       b = &src_other;
+                               } else {
+                                       b = ren1->pair->two;
+                                       a = &src_other;
+                               }
+                               mfi = merge_file(o, a, b,
+                                               branchNameA, branchNameB);
 
-                               if ( mfi.merge || !mfi.clean )
+                               if (mfi.merge || !mfi.clean)
                                        output("Renaming %s => %s", ren1_src, ren1_dst);
-                               if ( mfi.merge )
+                               if (mfi.merge)
                                        output("Auto-merging %s", ren1_dst);
-                               if ( !mfi.clean ) {
+                               if (!mfi.clean) {
                                        output("CONFLICT (rename/modify): Merge conflict in %s",
                                               ren1_dst);
                                        cleanMerge = 0;
 
-                                       if ( !index_only )
+                                       if (!index_only)
                                                update_stages(ren1_dst,
-                                                             osha, omode,
-                                                             asha, amode,
-                                                             bsha, bmode,
-                                                             1 /* clear */);
+                                                               o, a, b, 1);
                                }
                                update_file(mfi.clean, mfi.sha, mfi.mode, ren1_dst);
                        }
                }
        }
-       path_list_clear(&srcNames, 0);
-       debug("  processRenames done\n");
+       path_list_clear(&byDstA, 0);
+       path_list_clear(&byDstB, 0);
 
        if (cache_dirty)
                flush_cache();
@@ -1229,20 +1065,20 @@ static int process_entry(const char *path, struct stage_data *entry,
        unsigned aMode = entry->stages[2].mode;
        unsigned bMode = entry->stages[3].mode;
 
-       if ( oSha && (!aSha || !bSha) ) {
+       if (oSha && (!aSha || !bSha)) {
                /* Case A: Deleted in one */
-               if ( (!aSha && !bSha) ||
-                    (sha_eq(aSha, oSha) && !bSha) ||
-                    (!aSha && sha_eq(bSha, oSha)) ) {
+               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 )
+                       if (aSha)
                                output("Removing %s", path);
                        remove_file(1, path);
                } else {
                        /* Deleted in one and changed in the other */
                        cleanMerge = 0;
-                       if ( !aSha ) {
+                       if (!aSha) {
                                output("CONFLICT (delete/modify): %s deleted in %s "
                                       "and modified in %s. Version %s of %s left in tree.",
                                       path, branch1Name,
@@ -1257,8 +1093,8 @@ static int process_entry(const char *path, struct stage_data *entry,
                        }
                }
 
-       } else if ( (!oSha && aSha && !bSha) ||
-                   (!oSha && !aSha && bSha) ) {
+       } else if ((!oSha && aSha && !bSha) ||
+                  (!oSha && !aSha && bSha)) {
                /* Case B: Added in one. */
                const char *addBranch;
                const char *otherBranch;
@@ -1266,7 +1102,7 @@ static int process_entry(const char *path, struct stage_data *entry,
                const unsigned char *sha;
                const char *conf;
 
-               if ( aSha ) {
+               if (aSha) {
                        addBranch = branch1Name;
                        otherBranch = branch2Name;
                        mode = aMode;
@@ -1279,9 +1115,9 @@ static int process_entry(const char *path, struct stage_data *entry,
                        sha = bSha;
                        conf = "directory/file";
                }
-               if ( path_list_has_path(&currentDirectorySet, path) ) {
-                       cleanMerge = 0;
+               if (path_list_has_path(&currentDirectorySet, path)) {
                        const char *newPath = unique_path(path, addBranch);
+                       cleanMerge = 0;
                        output("CONFLICT (%s): There is a directory with name %s in %s. "
                               "Adding %s as %s",
                               conf, path, otherBranch, path, newPath);
@@ -1291,10 +1127,10 @@ static int process_entry(const char *path, struct stage_data *entry,
                        output("Adding %s", path);
                        update_file(1, sha, mode, path);
                }
-       } else if ( !oSha && aSha && bSha ) {
+       } else if (!oSha && aSha && bSha) {
                /* Case C: Added in both (check for same permissions). */
-               if ( sha_eq(aSha, bSha) ) {
-                       if ( aMode != bMode ) {
+               if (sha_eq(aSha, bSha)) {
+                       if (aMode != bMode) {
                                cleanMerge = 0;
                                output("CONFLICT: File %s added identically in both branches, "
                                       "but permissions conflict %06o->%06o",
@@ -1306,9 +1142,10 @@ static int process_entry(const char *path, struct stage_data *entry,
                                assert(0 && "This case must be handled by git-read-tree");
                        }
                } else {
+                       const char *newPath1, *newPath2;
                        cleanMerge = 0;
-                       const char *newPath1 = unique_path(path, branch1Name);
-                       const char *newPath2 = unique_path(path, branch2Name);
+                       newPath1 = unique_path(path, branch1Name);
+                       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);
@@ -1317,22 +1154,30 @@ static int process_entry(const char *path, struct stage_data *entry,
                        update_file(0, bSha, bMode, newPath2);
                }
 
-       } else if ( oSha && aSha && bSha ) {
+       } 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,
+               struct diff_filespec o, a, b;
+
+               output("Auto-merging %s", path);
+               o.path = a.path = b.path = (char *)path;
+               memcpy(o.sha1, oSha, 20);
+               o.mode = oMode;
+               memcpy(a.sha1, aSha, 20);
+               a.mode = aMode;
+               memcpy(b.sha1, bSha, 20);
+               b.mode = bMode;
+
+               mfi = merge_file(&o, &a, &b,
                                 branch1Name, branch2Name);
 
-               if ( mfi.clean )
+               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 )
+                       if (index_only)
                                update_file(0, mfi.sha, mfi.mode, path);
                        else
                                update_file_flags(mfi.sha, mfi.mode, path,
@@ -1347,73 +1192,68 @@ static int process_entry(const char *path, struct stage_data *entry,
        return cleanMerge;
 }
 
-static struct merge_tree_result merge_trees(struct tree *head,
-                                           struct tree *merge,
-                                           struct tree *common,
-                                           const char *branch1Name,
-                                           const char *branch2Name)
+static int merge_trees(struct tree *head,
+                      struct tree *merge,
+                      struct tree *common,
+                      const char *branch1Name,
+                      const char *branch2Name,
+                      struct tree **result)
 {
-       int code;
-       struct merge_tree_result result = { NULL, 0 };
-       if ( !memcmp(common->object.sha1, merge->object.sha1, 20) ) {
+       int code, clean;
+       if (sha_eq(common->object.sha1, merge->object.sha1)) {
                output("Already uptodate!");
-               result.tree = head;
-               result.clean = 1;
-               return result;
+               *result = head;
+               return 1;
        }
 
-       debug("merge_trees ...\n");
        code = git_merge_trees(index_only ? "-i": "-u", common, head, merge);
 
-       if ( code != 0 )
+       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();
+       *result = git_write_tree();
 
-       if ( !result.tree ) {
+       if (!*result) {
+               struct path_list *entries, *re_head, *re_merge;
+               int i;
                path_list_clear(&currentFileSet, 1);
                path_list_clear(&currentDirectorySet, 1);
-               get_files_dirs(head, &currentFileSet, &currentDirectorySet);
-               get_files_dirs(merge, &currentFileSet, &currentDirectorySet);
+               get_files_dirs(head);
+               get_files_dirs(merge);
 
-               struct path_list *entries = get_unmerged();
-               struct path_list *re_head, *re_merge;
+               entries = get_unmerged();
                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;
+               clean = process_renames(re_head, re_merge,
+                               branch1Name, branch2Name);
                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;
+                               clean = 0;
                }
 
-               free_rename_entries(&re_merge);
-               free_rename_entries(&re_head);
-               free_index_entries(&entries);
+               path_list_clear(re_merge, 0);
+               path_list_clear(re_head, 0);
+               path_list_clear(entries, 1);
 
-               if (result.clean || index_only)
-                       result.tree = git_write_tree();
+               if (clean || index_only)
+                       *result = git_write_tree();
                else
-                       result.tree = NULL;
-               debug("\t  processing entries done\n");
+                       *result = NULL;
        } else {
-               result.clean = 1;
+               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));
+                      sha1_to_hex((*result)->object.sha1));
        }
 
-       debug("  merge_trees done\n");
-       return result;
+       return clean;
 }
 
 /*
@@ -1421,76 +1261,75 @@ static struct merge_tree_result merge_trees(struct tree *head,
  * commit object and a flag indicating the cleaness of the merge.
  */
 static
-struct merge_result merge(struct commit *h1,
+int merge(struct commit *h1,
                          struct commit *h2,
                          const char *branch1Name,
                          const char *branch2Name,
                          int callDepth /* =0 */,
-                         struct commit *ancestor /* =None */)
+                         struct commit *ancestor /* =None */,
+                         struct commit **result)
 {
-       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;
+       struct tree *mrtree;
+       int clean;
 
        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);
+       output_commit_title(h1);
+       output_commit_title(h2);
 
-       if ( ancestor )
+       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);
-       }
+       for (iter = ca; iter; iter = iter->next)
+               output_commit_title(iter->item);
 
        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;
+               /*
+                * 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(mergedCA, iter->item,
+                     "Temporary merge branch 1",
+                     "Temporary merge branch 2",
+                     callDepth + 1,
+                     NULL,
+                     &mergedCA);
                output_indent = callDepth;
 
-               if ( !mergedCA )
+               if (!mergedCA)
                        die("merge returned no commit");
        }
 
-       if ( callDepth == 0 ) {
-               setup_index(0);
+       if (callDepth == 0) {
+               setup_index(0 /* $GIT_DIR/index */);
                index_only = 0;
        } else {
-               setup_index(1);
+               setup_index(1 /* temporary index */);
                git_read_tree(h1->tree);
                index_only = 1;
        }
 
-       mtr = merge_trees(h1->tree, h2->tree,
-                         mergedCA->tree, branch1Name, branch2Name);
+       clean = merge_trees(h1->tree, h2->tree, mergedCA->tree,
+                           branch1Name, branch2Name, &mrtree);
 
-       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);
+       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.commit = NULL;
+               *result = NULL;
 
-       result.clean = mtr.clean;
-       return result;
+       return clean;
 }
 
 static struct commit *get_ref(const char *ref)
@@ -1512,6 +1351,9 @@ 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");
 
@@ -1523,7 +1365,6 @@ int main(int argc, char *argv[])
        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;
@@ -1533,26 +1374,23 @@ int main(int argc, char *argv[])
        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);
+       h1 = get_ref(branch1);
+       h2 = get_ref(branch2);
 
        if (bases_count == 1) {
                struct commit *ancestor = get_ref(bases[0]);
-               result = merge(h1, h2, branch1, branch2, 0, ancestor);
+               clean = merge(h1, h2, branch1, branch2, 0, ancestor, &result);
        } else
-               result = merge(h1, h2, branch1, branch2, 0, NULL);
+               clean = merge(h1, h2, branch1, branch2, 0, NULL, &result);
 
        if (cache_dirty)
                flush_cache();
 
-       return result.clean ? 0: 1;
+       return clean ? 0: 1;
 }
 
 /*