test-lib: introduce test_commit_bulk
[gitweb.git] / merge-recursive.c
index 6126773a7bfbd21ef38471d69d36b262e50a4050..d2e380b7ed845e6fb2cd5616754a3f12a11c7b18 100644 (file)
@@ -115,32 +115,32 @@ static void collision_init(struct hashmap *map)
        hashmap_init(map, (hashmap_cmp_fn) collision_cmp, NULL, 0);
 }
 
-static void flush_output(struct merge_options *o)
+static void flush_output(struct merge_options *opt)
 {
-       if (o->buffer_output < 2 && o->obuf.len) {
-               fputs(o->obuf.buf, stdout);
-               strbuf_reset(&o->obuf);
+       if (opt->buffer_output < 2 && opt->obuf.len) {
+               fputs(opt->obuf.buf, stdout);
+               strbuf_reset(&opt->obuf);
        }
 }
 
-static int err(struct merge_options *o, const char *err, ...)
+static int err(struct merge_options *opt, const char *err, ...)
 {
        va_list params;
 
-       if (o->buffer_output < 2)
-               flush_output(o);
+       if (opt->buffer_output < 2)
+               flush_output(opt);
        else {
-               strbuf_complete(&o->obuf, '\n');
-               strbuf_addstr(&o->obuf, "error: ");
+               strbuf_complete(&opt->obuf, '\n');
+               strbuf_addstr(&opt->obuf, "error: ");
        }
        va_start(params, err);
-       strbuf_vaddf(&o->obuf, err, params);
+       strbuf_vaddf(&opt->obuf, err, params);
        va_end(params);
-       if (o->buffer_output > 1)
-               strbuf_addch(&o->obuf, '\n');
+       if (opt->buffer_output > 1)
+               strbuf_addch(&opt->obuf, '\n');
        else {
-               error("%s", o->obuf.buf);
-               strbuf_reset(&o->obuf);
+               error("%s", opt->obuf.buf);
+               strbuf_reset(&opt->obuf);
        }
 
        return -1;
@@ -163,6 +163,11 @@ static struct tree *shift_tree_object(struct repository *repo,
        return lookup_tree(repo, &shifted);
 }
 
+static inline void set_commit_tree(struct commit *c, struct tree *t)
+{
+       c->maybe_tree = t;
+}
+
 static struct commit *make_virtual_commit(struct repository *repo,
                                          struct tree *tree,
                                          const char *comment)
@@ -170,7 +175,7 @@ static struct commit *make_virtual_commit(struct repository *repo,
        struct commit *commit = alloc_commit_node(repo);
 
        set_merge_remote_desc(commit, comment, (struct object *)commit);
-       commit->maybe_tree = tree;
+       set_commit_tree(commit, tree);
        commit->object.parsed = 1;
        return commit;
 }
@@ -196,163 +201,148 @@ enum rename_type {
        RENAME_TWO_FILES_TO_ONE
 };
 
-struct rename_conflict_info {
-       enum rename_type rename_type;
-       struct diff_filepair *pair1;
-       struct diff_filepair *pair2;
-       const char *branch1;
-       const char *branch2;
-       struct stage_data *dst_entry1;
-       struct stage_data *dst_entry2;
-       struct diff_filespec ren1_other;
-       struct diff_filespec ren2_other;
-};
-
 /*
  * Since we want to write the index eventually, we cannot reuse the index
  * for these (temporary) data.
  */
 struct stage_data {
-       struct {
-               unsigned mode;
-               struct object_id oid;
-       } stages[4];
+       struct diff_filespec stages[4]; /* mostly for oid & mode; maybe path */
        struct rename_conflict_info *rename_conflict_info;
        unsigned processed:1;
 };
 
+struct rename {
+       unsigned processed:1;
+       struct diff_filepair *pair;
+       const char *branch; /* branch that the rename occurred on */
+       /*
+        * If directory rename detection affected this rename, what was its
+        * original type ('A' or 'R') and it's original destination before
+        * the directory rename (otherwise, '\0' and NULL for these two vars).
+        */
+       char dir_rename_original_type;
+       char *dir_rename_original_dest;
+       /*
+        * Purpose of src_entry and dst_entry:
+        *
+        * If 'before' is renamed to 'after' then src_entry will contain
+        * the versions of 'before' from the merge_base, HEAD, and MERGE in
+        * stages 1, 2, and 3; dst_entry will contain the respective
+        * versions of 'after' in corresponding locations.  Thus, we have a
+        * total of six modes and oids, though some will be null.  (Stage 0
+        * is ignored; we're interested in handling conflicts.)
+        *
+        * Since we don't turn on break-rewrites by default, neither
+        * src_entry nor dst_entry can have all three of their stages have
+        * non-null oids, meaning at most four of the six will be non-null.
+        * Also, since this is a rename, both src_entry and dst_entry will
+        * have at least one non-null oid, meaning at least two will be
+        * non-null.  Of the six oids, a typical rename will have three be
+        * non-null.  Only two implies a rename/delete, and four implies a
+        * rename/add.
+        */
+       struct stage_data *src_entry;
+       struct stage_data *dst_entry;
+};
+
+struct rename_conflict_info {
+       enum rename_type rename_type;
+       struct rename *ren1;
+       struct rename *ren2;
+};
+
 static inline void setup_rename_conflict_info(enum rename_type rename_type,
-                                             struct diff_filepair *pair1,
-                                             struct diff_filepair *pair2,
-                                             const char *branch1,
-                                             const char *branch2,
-                                             struct stage_data *dst_entry1,
-                                             struct stage_data *dst_entry2,
-                                             struct merge_options *o,
-                                             struct stage_data *src_entry1,
-                                             struct stage_data *src_entry2)
-{
-       int ostage1 = 0, ostage2;
+                                             struct merge_options *opt,
+                                             struct rename *ren1,
+                                             struct rename *ren2)
+{
        struct rename_conflict_info *ci;
 
        /*
         * When we have two renames involved, it's easiest to get the
         * correct things into stage 2 and 3, and to make sure that the
         * content merge puts HEAD before the other branch if we just
-        * ensure that branch1 == o->branch1.  So, simply flip arguments
+        * ensure that branch1 == opt->branch1.  So, simply flip arguments
         * around if we don't have that.
         */
-       if (dst_entry2 && branch1 != o->branch1) {
-               setup_rename_conflict_info(rename_type,
-                                          pair2,      pair1,
-                                          branch2,    branch1,
-                                          dst_entry2, dst_entry1,
-                                          o,
-                                          src_entry2, src_entry1);
+       if (ren2 && ren1->branch != opt->branch1) {
+               setup_rename_conflict_info(rename_type, opt, ren2, ren1);
                return;
        }
 
        ci = xcalloc(1, sizeof(struct rename_conflict_info));
        ci->rename_type = rename_type;
-       ci->pair1 = pair1;
-       ci->branch1 = branch1;
-       ci->branch2 = branch2;
-
-       ci->dst_entry1 = dst_entry1;
-       dst_entry1->rename_conflict_info = ci;
-       dst_entry1->processed = 0;
-
-       assert(!pair2 == !dst_entry2);
-       if (dst_entry2) {
-               ci->dst_entry2 = dst_entry2;
-               ci->pair2 = pair2;
-               dst_entry2->rename_conflict_info = ci;
-       }
+       ci->ren1 = ren1;
+       ci->ren2 = ren2;
 
-       /*
-        * For each rename, there could have been
-        * modifications on the side of history where that
-        * file was not renamed.
-        */
-       if (rename_type == RENAME_ADD ||
-           rename_type == RENAME_TWO_FILES_TO_ONE) {
-               ostage1 = o->branch1 == branch1 ? 3 : 2;
-
-               ci->ren1_other.path = pair1->one->path;
-               oidcpy(&ci->ren1_other.oid, &src_entry1->stages[ostage1].oid);
-               ci->ren1_other.mode = src_entry1->stages[ostage1].mode;
-       }
-
-       if (rename_type == RENAME_TWO_FILES_TO_ONE) {
-               ostage2 = ostage1 ^ 1;
-
-               ci->ren2_other.path = pair2->one->path;
-               oidcpy(&ci->ren2_other.oid, &src_entry2->stages[ostage2].oid);
-               ci->ren2_other.mode = src_entry2->stages[ostage2].mode;
+       ci->ren1->dst_entry->processed = 0;
+       ci->ren1->dst_entry->rename_conflict_info = ci;
+       if (ren2) {
+               ci->ren2->dst_entry->rename_conflict_info = ci;
        }
 }
 
-static int show(struct merge_options *o, int v)
+static int show(struct merge_options *opt, int v)
 {
-       return (!o->call_depth && o->verbosity >= v) || o->verbosity >= 5;
+       return (!opt->call_depth && opt->verbosity >= v) || opt->verbosity >= 5;
 }
 
 __attribute__((format (printf, 3, 4)))
-static void output(struct merge_options *o, int v, const char *fmt, ...)
+static void output(struct merge_options *opt, int v, const char *fmt, ...)
 {
        va_list ap;
 
-       if (!show(o, v))
+       if (!show(opt, v))
                return;
 
-       strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
+       strbuf_addchars(&opt->obuf, ' ', opt->call_depth * 2);
 
        va_start(ap, fmt);
-       strbuf_vaddf(&o->obuf, fmt, ap);
+       strbuf_vaddf(&opt->obuf, fmt, ap);
        va_end(ap);
 
-       strbuf_addch(&o->obuf, '\n');
-       if (!o->buffer_output)
-               flush_output(o);
+       strbuf_addch(&opt->obuf, '\n');
+       if (!opt->buffer_output)
+               flush_output(opt);
 }
 
-static void output_commit_title(struct merge_options *o, struct commit *commit)
+static void output_commit_title(struct merge_options *opt, struct commit *commit)
 {
        struct merge_remote_desc *desc;
 
-       strbuf_addchars(&o->obuf, ' ', o->call_depth * 2);
+       strbuf_addchars(&opt->obuf, ' ', opt->call_depth * 2);
        desc = merge_remote_util(commit);
        if (desc)
-               strbuf_addf(&o->obuf, "virtual %s\n", desc->name);
+               strbuf_addf(&opt->obuf, "virtual %s\n", desc->name);
        else {
-               strbuf_add_unique_abbrev(&o->obuf, &commit->object.oid,
+               strbuf_add_unique_abbrev(&opt->obuf, &commit->object.oid,
                                         DEFAULT_ABBREV);
-               strbuf_addch(&o->obuf, ' ');
+               strbuf_addch(&opt->obuf, ' ');
                if (parse_commit(commit) != 0)
-                       strbuf_addstr(&o->obuf, _("(bad commit)\n"));
+                       strbuf_addstr(&opt->obuf, _("(bad commit)\n"));
                else {
                        const char *title;
                        const char *msg = get_commit_buffer(commit, NULL);
                        int len = find_commit_subject(msg, &title);
                        if (len)
-                               strbuf_addf(&o->obuf, "%.*s\n", len, title);
+                               strbuf_addf(&opt->obuf, "%.*s\n", len, title);
                        unuse_commit_buffer(commit, msg);
                }
        }
-       flush_output(o);
+       flush_output(opt);
 }
 
-static int add_cacheinfo(struct merge_options *o,
-                        unsigned int mode, const struct object_id *oid,
+static int add_cacheinfo(struct merge_options *opt,
+                        const struct diff_filespec *blob,
                         const char *path, int stage, int refresh, int options)
 {
-       struct index_state *istate = o->repo->index;
+       struct index_state *istate = opt->repo->index;
        struct cache_entry *ce;
        int ret;
 
-       ce = make_cache_entry(istate, mode, oid ? oid : &null_oid, path, stage, 0);
+       ce = make_cache_entry(istate, blob->mode, &blob->oid, path, stage, 0);
        if (!ce)
-               return err(o, _("add_cacheinfo failed for path '%s'; merge aborting."), path);
+               return err(opt, _("add_cacheinfo failed for path '%s'; merge aborting."), path);
 
        ret = add_index_entry(istate, ce, options);
        if (refresh) {
@@ -361,7 +351,7 @@ static int add_cacheinfo(struct merge_options *o,
                nce = refresh_cache_entry(istate, ce,
                                          CE_MATCH_REFRESH | CE_MATCH_IGNORE_MISSING);
                if (!nce)
-                       return err(o, _("add_cacheinfo failed to refresh for path '%s'; merge aborting."), path);
+                       return err(opt, _("add_cacheinfo failed to refresh for path '%s'; merge aborting."), path);
                if (nce != ce)
                        ret = add_index_entry(istate, nce, options);
        }
@@ -374,7 +364,7 @@ static void init_tree_desc_from_tree(struct tree_desc *desc, struct tree *tree)
        init_tree_desc(desc, tree->buffer, tree->size);
 }
 
-static int unpack_trees_start(struct merge_options *o,
+static int unpack_trees_start(struct merge_options *opt,
                              struct tree *common,
                              struct tree *head,
                              struct tree *merge)
@@ -383,49 +373,49 @@ static int unpack_trees_start(struct merge_options *o,
        struct tree_desc t[3];
        struct index_state tmp_index = { NULL };
 
-       memset(&o->unpack_opts, 0, sizeof(o->unpack_opts));
-       if (o->call_depth)
-               o->unpack_opts.index_only = 1;
+       memset(&opt->unpack_opts, 0, sizeof(opt->unpack_opts));
+       if (opt->call_depth)
+               opt->unpack_opts.index_only = 1;
        else
-               o->unpack_opts.update = 1;
-       o->unpack_opts.merge = 1;
-       o->unpack_opts.head_idx = 2;
-       o->unpack_opts.fn = threeway_merge;
-       o->unpack_opts.src_index = o->repo->index;
-       o->unpack_opts.dst_index = &tmp_index;
-       o->unpack_opts.aggressive = !merge_detect_rename(o);
-       setup_unpack_trees_porcelain(&o->unpack_opts, "merge");
+               opt->unpack_opts.update = 1;
+       opt->unpack_opts.merge = 1;
+       opt->unpack_opts.head_idx = 2;
+       opt->unpack_opts.fn = threeway_merge;
+       opt->unpack_opts.src_index = opt->repo->index;
+       opt->unpack_opts.dst_index = &tmp_index;
+       opt->unpack_opts.aggressive = !merge_detect_rename(opt);
+       setup_unpack_trees_porcelain(&opt->unpack_opts, "merge");
 
        init_tree_desc_from_tree(t+0, common);
        init_tree_desc_from_tree(t+1, head);
        init_tree_desc_from_tree(t+2, merge);
 
-       rc = unpack_trees(3, t, &o->unpack_opts);
-       cache_tree_free(&o->repo->index->cache_tree);
+       rc = unpack_trees(3, t, &opt->unpack_opts);
+       cache_tree_free(&opt->repo->index->cache_tree);
 
        /*
-        * Update o->repo->index to match the new results, AFTER saving a copy
-        * in o->orig_index.  Update src_index to point to the saved copy.
+        * Update opt->repo->index to match the new results, AFTER saving a copy
+        * in opt->orig_index.  Update src_index to point to the saved copy.
         * (verify_uptodate() checks src_index, and the original index is
         * the one that had the necessary modification timestamps.)
         */
-       o->orig_index = *o->repo->index;
-       *o->repo->index = tmp_index;
-       o->unpack_opts.src_index = &o->orig_index;
+       opt->orig_index = *opt->repo->index;
+       *opt->repo->index = tmp_index;
+       opt->unpack_opts.src_index = &opt->orig_index;
 
        return rc;
 }
 
-static void unpack_trees_finish(struct merge_options *o)
+static void unpack_trees_finish(struct merge_options *opt)
 {
-       discard_index(&o->orig_index);
-       clear_unpack_trees_porcelain(&o->unpack_opts);
+       discard_index(&opt->orig_index);
+       clear_unpack_trees_porcelain(&opt->unpack_opts);
 }
 
-struct tree *write_tree_from_memory(struct merge_options *o)
+struct tree *write_tree_from_memory(struct merge_options *opt)
 {
        struct tree *result = NULL;
-       struct index_state *istate = o->repo->index;
+       struct index_state *istate = opt->repo->index;
 
        if (unmerged_index(istate)) {
                int i;
@@ -444,11 +434,11 @@ struct tree *write_tree_from_memory(struct merge_options *o)
 
        if (!cache_tree_fully_valid(istate->cache_tree) &&
            cache_tree_update(istate, 0) < 0) {
-               err(o, _("error building trees"));
+               err(opt, _("error building trees"));
                return NULL;
        }
 
-       result = lookup_tree(o->repo, &istate->cache_tree->oid);
+       result = lookup_tree(opt->repo, &istate->cache_tree->oid);
 
        return result;
 }
@@ -459,37 +449,36 @@ static int save_files_dirs(const struct object_id *oid,
 {
        struct path_hashmap_entry *entry;
        int baselen = base->len;
-       struct merge_options *o = context;
+       struct merge_options *opt = context;
 
        strbuf_addstr(base, path);
 
        FLEX_ALLOC_MEM(entry, path, base->buf, base->len);
        hashmap_entry_init(entry, path_hash(entry->path));
-       hashmap_add(&o->current_file_dir_set, entry);
+       hashmap_add(&opt->current_file_dir_set, entry);
 
        strbuf_setlen(base, baselen);
        return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 }
 
-static void get_files_dirs(struct merge_options *o, struct tree *tree)
+static void get_files_dirs(struct merge_options *opt, struct tree *tree)
 {
        struct pathspec match_all;
        memset(&match_all, 0, sizeof(match_all));
        read_tree_recursive(the_repository, tree, "", 0, 0,
-                           &match_all, save_files_dirs, o);
+                           &match_all, save_files_dirs, opt);
 }
 
 static int get_tree_entry_if_blob(const struct object_id *tree,
                                  const char *path,
-                                 struct object_id *hashy,
-                                 unsigned int *mode_o)
+                                 struct diff_filespec *dfs)
 {
        int ret;
 
-       ret = get_tree_entry(tree, path, hashy, mode_o);
-       if (S_ISDIR(*mode_o)) {
-               oidcpy(hashy, &null_oid);
-               *mode_o = 0;
+       ret = get_tree_entry(tree, path, &dfs->oid, &dfs->mode);
+       if (S_ISDIR(dfs->mode)) {
+               oidcpy(&dfs->oid, &null_oid);
+               dfs->mode = 0;
        }
        return ret;
 }
@@ -504,12 +493,9 @@ static struct stage_data *insert_stage_data(const char *path,
 {
        struct string_list_item *item;
        struct stage_data *e = xcalloc(1, sizeof(struct stage_data));
-       get_tree_entry_if_blob(&o->object.oid, path,
-                              &e->stages[1].oid, &e->stages[1].mode);
-       get_tree_entry_if_blob(&a->object.oid, path,
-                              &e->stages[2].oid, &e->stages[2].mode);
-       get_tree_entry_if_blob(&b->object.oid, path,
-                              &e->stages[3].oid, &e->stages[3].mode);
+       get_tree_entry_if_blob(&o->object.oid, path, &e->stages[1]);
+       get_tree_entry_if_blob(&a->object.oid, path, &e->stages[2]);
+       get_tree_entry_if_blob(&b->object.oid, path, &e->stages[3]);
        item = string_list_insert(entries, path);
        item->util = e;
        return e;
@@ -573,7 +559,7 @@ static int string_list_df_name_compare(const char *one, const char *two)
        return onelen - twolen;
 }
 
-static void record_df_conflict_files(struct merge_options *o,
+static void record_df_conflict_files(struct merge_options *opt,
                                     struct string_list *entries)
 {
        /* If there is a D/F conflict and the file for such a conflict
@@ -598,7 +584,7 @@ static void record_df_conflict_files(struct merge_options *o,
         * If we're merging merge-bases, we don't want to bother with
         * any working directory changes.
         */
-       if (o->call_depth)
+       if (opt->call_depth)
                return;
 
        /* Ensure D/F conflicts are adjacent in the entries list. */
@@ -610,7 +596,7 @@ static void record_df_conflict_files(struct merge_options *o,
        df_sorted_entries.cmp = string_list_df_name_compare;
        string_list_sort(&df_sorted_entries);
 
-       string_list_clear(&o->df_conflict_file_set, 1);
+       string_list_clear(&opt->df_conflict_file_set, 1);
        for (i = 0; i < df_sorted_entries.nr; i++) {
                const char *path = df_sorted_entries.items[i].string;
                int len = strlen(path);
@@ -626,7 +612,7 @@ static void record_df_conflict_files(struct merge_options *o,
                    len > last_len &&
                    memcmp(path, last_file, last_len) == 0 &&
                    path[last_len] == '/') {
-                       string_list_insert(&o->df_conflict_file_set, last_file);
+                       string_list_insert(&opt->df_conflict_file_set, last_file);
                }
 
                /*
@@ -645,33 +631,6 @@ static void record_df_conflict_files(struct merge_options *o,
        string_list_clear(&df_sorted_entries, 0);
 }
 
-struct rename {
-       struct diff_filepair *pair;
-       /*
-        * Purpose of src_entry and dst_entry:
-        *
-        * If 'before' is renamed to 'after' then src_entry will contain
-        * the versions of 'before' from the merge_base, HEAD, and MERGE in
-        * stages 1, 2, and 3; dst_entry will contain the respective
-        * versions of 'after' in corresponding locations.  Thus, we have a
-        * total of six modes and oids, though some will be null.  (Stage 0
-        * is ignored; we're interested in handling conflicts.)
-        *
-        * Since we don't turn on break-rewrites by default, neither
-        * src_entry nor dst_entry can have all three of their stages have
-        * non-null oids, meaning at most four of the six will be non-null.
-        * Also, since this is a rename, both src_entry and dst_entry will
-        * have at least one non-null oid, meaning at least two will be
-        * non-null.  Of the six oids, a typical rename will have three be
-        * non-null.  Only two implies a rename/delete, and four implies a
-        * rename/add.
-        */
-       struct stage_data *src_entry;
-       struct stage_data *dst_entry;
-       unsigned add_turned_into_rename:1;
-       unsigned processed:1;
-};
-
 static int update_stages(struct merge_options *opt, const char *path,
                         const struct diff_filespec *o,
                         const struct diff_filespec *a,
@@ -692,13 +651,13 @@ static int update_stages(struct merge_options *opt, const char *path,
                if (remove_file_from_index(opt->repo->index, path))
                        return -1;
        if (o)
-               if (add_cacheinfo(opt, o->mode, &o->oid, path, 1, 0, options))
+               if (add_cacheinfo(opt, o, path, 1, 0, options))
                        return -1;
        if (a)
-               if (add_cacheinfo(opt, a->mode, &a->oid, path, 2, 0, options))
+               if (add_cacheinfo(opt, a, path, 2, 0, options))
                        return -1;
        if (b)
-               if (add_cacheinfo(opt, b->mode, &b->oid, path, 3, 0, options))
+               if (add_cacheinfo(opt, b, path, 3, 0, options))
                        return -1;
        return 0;
 }
@@ -717,20 +676,20 @@ static void update_entry(struct stage_data *entry,
        oidcpy(&entry->stages[3].oid, &b->oid);
 }
 
-static int remove_file(struct merge_options *o, int clean,
+static int remove_file(struct merge_options *opt, int clean,
                       const char *path, int no_wd)
 {
-       int update_cache = o->call_depth || clean;
-       int update_working_directory = !o->call_depth && !no_wd;
+       int update_cache = opt->call_depth || clean;
+       int update_working_directory = !opt->call_depth && !no_wd;
 
        if (update_cache) {
-               if (remove_file_from_index(o->repo->index, path))
+               if (remove_file_from_index(opt->repo->index, path))
                        return -1;
        }
        if (update_working_directory) {
                if (ignore_case) {
                        struct cache_entry *ce;
-                       ce = index_file_exists(o->repo->index, path, strlen(path),
+                       ce = index_file_exists(opt->repo->index, path, strlen(path),
                                               ignore_case);
                        if (ce && ce_stage(ce) == 0 && strcmp(path, ce->name))
                                return 0;
@@ -751,7 +710,7 @@ static void add_flattened_path(struct strbuf *out, const char *s)
                        out->buf[i] = '_';
 }
 
-static char *unique_path(struct merge_options *o, const char *path, const char *branch)
+static char *unique_path(struct merge_options *opt, const char *path, const char *branch)
 {
        struct path_hashmap_entry *entry;
        struct strbuf newpath = STRBUF_INIT;
@@ -762,16 +721,16 @@ static char *unique_path(struct merge_options *o, const char *path, const char *
        add_flattened_path(&newpath, branch);
 
        base_len = newpath.len;
-       while (hashmap_get_from_hash(&o->current_file_dir_set,
+       while (hashmap_get_from_hash(&opt->current_file_dir_set,
                                     path_hash(newpath.buf), newpath.buf) ||
-              (!o->call_depth && file_exists(newpath.buf))) {
+              (!opt->call_depth && file_exists(newpath.buf))) {
                strbuf_setlen(&newpath, base_len);
                strbuf_addf(&newpath, "_%d", suffix++);
        }
 
        FLEX_ALLOC_MEM(entry, path, newpath.buf, newpath.len);
        hashmap_entry_init(entry, path_hash(entry->path));
-       hashmap_add(&o->current_file_dir_set, entry);
+       hashmap_add(&opt->current_file_dir_set, entry);
        return strbuf_detach(&newpath, NULL);
 }
 
@@ -810,10 +769,10 @@ static int dir_in_way(struct index_state *istate, const char *path,
  * Returns whether path was tracked in the index before the merge started,
  * and its oid and mode match the specified values
  */
-static int was_tracked_and_matches(struct merge_options *o, const char *path,
-                                  const struct object_id *oid, unsigned mode)
+static int was_tracked_and_matches(struct merge_options *opt, const char *path,
+                                  const struct diff_filespec *blob)
 {
-       int pos = index_name_pos(&o->orig_index, path, strlen(path));
+       int pos = index_name_pos(&opt->orig_index, path, strlen(path));
        struct cache_entry *ce;
 
        if (0 > pos)
@@ -821,16 +780,16 @@ static int was_tracked_and_matches(struct merge_options *o, const char *path,
                return 0;
 
        /* See if the file we were tracking before matches */
-       ce = o->orig_index.cache[pos];
-       return (oid_eq(&ce->oid, oid) && ce->ce_mode == mode);
+       ce = opt->orig_index.cache[pos];
+       return (oid_eq(&ce->oid, &blob->oid) && ce->ce_mode == blob->mode);
 }
 
 /*
  * Returns whether path was tracked in the index before the merge started
  */
-static int was_tracked(struct merge_options *o, const char *path)
+static int was_tracked(struct merge_options *opt, const char *path)
 {
-       int pos = index_name_pos(&o->orig_index, path, strlen(path));
+       int pos = index_name_pos(&opt->orig_index, path, strlen(path));
 
        if (0 <= pos)
                /* we were tracking this path before the merge */
@@ -839,13 +798,13 @@ static int was_tracked(struct merge_options *o, const char *path)
        return 0;
 }
 
-static int would_lose_untracked(struct merge_options *o, const char *path)
+static int would_lose_untracked(struct merge_options *opt, const char *path)
 {
-       struct index_state *istate = o->repo->index;
+       struct index_state *istate = opt->repo->index;
 
        /*
         * This may look like it can be simplified to:
-        *   return !was_tracked(o, path) && file_exists(path)
+        *   return !was_tracked(opt, path) && file_exists(path)
         * but it can't.  This function needs to know whether path was in
         * the working tree due to EITHER having been tracked in the index
         * before the merge OR having been put into the working copy and
@@ -882,38 +841,38 @@ static int would_lose_untracked(struct merge_options *o, const char *path)
        return file_exists(path);
 }
 
-static int was_dirty(struct merge_options *o, const char *path)
+static int was_dirty(struct merge_options *opt, const char *path)
 {
        struct cache_entry *ce;
        int dirty = 1;
 
-       if (o->call_depth || !was_tracked(o, path))
+       if (opt->call_depth || !was_tracked(opt, path))
                return !dirty;
 
-       ce = index_file_exists(o->unpack_opts.src_index,
+       ce = index_file_exists(opt->unpack_opts.src_index,
                               path, strlen(path), ignore_case);
-       dirty = verify_uptodate(ce, &o->unpack_opts) != 0;
+       dirty = verify_uptodate(ce, &opt->unpack_opts) != 0;
        return dirty;
 }
 
-static int make_room_for_path(struct merge_options *o, const char *path)
+static int make_room_for_path(struct merge_options *opt, const char *path)
 {
        int status, i;
        const char *msg = _("failed to create path '%s'%s");
 
        /* Unlink any D/F conflict files that are in the way */
-       for (i = 0; i < o->df_conflict_file_set.nr; i++) {
-               const char *df_path = o->df_conflict_file_set.items[i].string;
+       for (i = 0; i < opt->df_conflict_file_set.nr; i++) {
+               const char *df_path = opt->df_conflict_file_set.items[i].string;
                size_t pathlen = strlen(path);
                size_t df_pathlen = strlen(df_path);
                if (df_pathlen < pathlen &&
                    path[df_pathlen] == '/' &&
                    strncmp(path, df_path, df_pathlen) == 0) {
-                       output(o, 3,
+                       output(opt, 3,
                               _("Removing %s to make room for subdirectory\n"),
                               df_path);
                        unlink(df_path);
-                       unsorted_string_list_delete_item(&o->df_conflict_file_set,
+                       unsorted_string_list_delete_item(&opt->df_conflict_file_set,
                                                         i, 0);
                        break;
                }
@@ -924,16 +883,16 @@ static int make_room_for_path(struct merge_options *o, const char *path)
        if (status) {
                if (status == SCLD_EXISTS)
                        /* something else exists */
-                       return err(o, msg, path, _(": perhaps a D/F conflict?"));
-               return err(o, msg, path, "");
+                       return err(opt, msg, path, _(": perhaps a D/F conflict?"));
+               return err(opt, msg, path, "");
        }
 
        /*
         * Do not unlink a file in the work tree if we are not
         * tracking it.
         */
-       if (would_lose_untracked(o, path))
-               return err(o, _("refusing to lose untracked file at '%s'"),
+       if (would_lose_untracked(opt, path))
+               return err(opt, _("refusing to lose untracked file at '%s'"),
                           path);
 
        /* Successful unlink is good.. */
@@ -943,19 +902,18 @@ static int make_room_for_path(struct merge_options *o, const char *path)
        if (errno == ENOENT)
                return 0;
        /* .. but not some other error (who really cares what?) */
-       return err(o, msg, path, _(": perhaps a D/F conflict?"));
+       return err(opt, msg, path, _(": perhaps a D/F conflict?"));
 }
 
-static int update_file_flags(struct merge_options *o,
-                            const struct object_id *oid,
-                            unsigned mode,
+static int update_file_flags(struct merge_options *opt,
+                            const struct diff_filespec *contents,
                             const char *path,
                             int update_cache,
                             int update_wd)
 {
        int ret = 0;
 
-       if (o->call_depth)
+       if (opt->call_depth)
                update_wd = 0;
 
        if (update_wd) {
@@ -963,7 +921,7 @@ static int update_file_flags(struct merge_options *o,
                void *buf;
                unsigned long size;
 
-               if (S_ISGITLINK(mode)) {
+               if (S_ISGITLINK(contents->mode)) {
                        /*
                         * We may later decide to recursively descend into
                         * the submodule directory and update its index
@@ -973,84 +931,84 @@ static int update_file_flags(struct merge_options *o,
                        goto update_index;
                }
 
-               buf = read_object_file(oid, &type, &size);
+               buf = read_object_file(&contents->oid, &type, &size);
                if (!buf)
-                       return err(o, _("cannot read object %s '%s'"), oid_to_hex(oid), path);
+                       return err(opt, _("cannot read object %s '%s'"),
+                                  oid_to_hex(&contents->oid), path);
                if (type != OBJ_BLOB) {
-                       ret = err(o, _("blob expected for %s '%s'"), oid_to_hex(oid), path);
+                       ret = err(opt, _("blob expected for %s '%s'"),
+                                 oid_to_hex(&contents->oid), path);
                        goto free_buf;
                }
-               if (S_ISREG(mode)) {
+               if (S_ISREG(contents->mode)) {
                        struct strbuf strbuf = STRBUF_INIT;
-                       if (convert_to_working_tree(o->repo->index, path, buf, size, &strbuf)) {
+                       if (convert_to_working_tree(opt->repo->index, path, buf, size, &strbuf)) {
                                free(buf);
                                size = strbuf.len;
                                buf = strbuf_detach(&strbuf, NULL);
                        }
                }
 
-               if (make_room_for_path(o, path) < 0) {
+               if (make_room_for_path(opt, path) < 0) {
                        update_wd = 0;
                        goto free_buf;
                }
-               if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
+               if (S_ISREG(contents->mode) ||
+                   (!has_symlinks && S_ISLNK(contents->mode))) {
                        int fd;
-                       if (mode & 0100)
-                               mode = 0777;
-                       else
-                               mode = 0666;
+                       int mode = (contents->mode & 0100 ? 0777 : 0666);
+
                        fd = open(path, O_WRONLY | O_TRUNC | O_CREAT, mode);
                        if (fd < 0) {
-                               ret = err(o, _("failed to open '%s': %s"),
+                               ret = err(opt, _("failed to open '%s': %s"),
                                          path, strerror(errno));
                                goto free_buf;
                        }
                        write_in_full(fd, buf, size);
                        close(fd);
-               } else if (S_ISLNK(mode)) {
+               } else if (S_ISLNK(contents->mode)) {
                        char *lnk = xmemdupz(buf, size);
                        safe_create_leading_directories_const(path);
                        unlink(path);
                        if (symlink(lnk, path))
-                               ret = err(o, _("failed to symlink '%s': %s"),
+                               ret = err(opt, _("failed to symlink '%s': %s"),
                                          path, strerror(errno));
                        free(lnk);
                } else
-                       ret = err(o,
+                       ret = err(opt,
                                  _("do not know what to do with %06o %s '%s'"),
-                                 mode, oid_to_hex(oid), path);
+                                 contents->mode, oid_to_hex(&contents->oid), path);
        free_buf:
                free(buf);
        }
 update_index:
        if (!ret && update_cache)
-               if (add_cacheinfo(o, mode, oid, path, 0, update_wd,
+               if (add_cacheinfo(opt, contents, path, 0, update_wd,
                                  ADD_CACHE_OK_TO_ADD))
                        return -1;
        return ret;
 }
 
-static int update_file(struct merge_options *o,
+static int update_file(struct merge_options *opt,
                       int clean,
-                      const struct object_id *oid,
-                      unsigned mode,
+                      const struct diff_filespec *contents,
                       const char *path)
 {
-       return update_file_flags(o, oid, mode, path, o->call_depth || clean, !o->call_depth);
+       return update_file_flags(opt, contents, path,
+                                opt->call_depth || clean, !opt->call_depth);
 }
 
 /* Low level file merging, update and removal */
 
 struct merge_file_info {
-       struct object_id oid;
-       unsigned mode;
+       struct diff_filespec blob; /* mostly use oid & mode; sometimes path */
        unsigned clean:1,
                 merge:1;
 };
 
-static int merge_3way(struct merge_options *o,
+static int merge_3way(struct merge_options *opt,
                      mmbuffer_t *result_buf,
-                     const struct diff_filespec *one,
+                     const struct diff_filespec *o,
                      const struct diff_filespec *a,
                      const struct diff_filespec *b,
                      const char *branch1,
@@ -1062,15 +1020,15 @@ static int merge_3way(struct merge_options *o,
        char *base_name, *name1, *name2;
        int merge_status;
 
-       ll_opts.renormalize = o->renormalize;
+       ll_opts.renormalize = opt->renormalize;
        ll_opts.extra_marker_size = extra_marker_size;
-       ll_opts.xdl_opts = o->xdl_opts;
+       ll_opts.xdl_opts = opt->xdl_opts;
 
-       if (o->call_depth) {
+       if (opt->call_depth) {
                ll_opts.virtual_ancestor = 1;
                ll_opts.variant = 0;
        } else {
-               switch (o->recursive_variant) {
+               switch (opt->recursive_variant) {
                case MERGE_RECURSIVE_OURS:
                        ll_opts.variant = XDL_MERGE_FAVOR_OURS;
                        break;
@@ -1083,26 +1041,27 @@ static int merge_3way(struct merge_options *o,
                }
        }
 
+       assert(a->path && b->path);
        if (strcmp(a->path, b->path) ||
-           (o->ancestor != NULL && strcmp(a->path, one->path) != 0)) {
-               base_name = o->ancestor == NULL ? NULL :
-                       mkpathdup("%s:%s", o->ancestor, one->path);
+           (opt->ancestor != NULL && strcmp(a->path, o->path) != 0)) {
+               base_name = opt->ancestor == NULL ? NULL :
+                       mkpathdup("%s:%s", opt->ancestor, o->path);
                name1 = mkpathdup("%s:%s", branch1, a->path);
                name2 = mkpathdup("%s:%s", branch2, b->path);
        } else {
-               base_name = o->ancestor == NULL ? NULL :
-                       mkpathdup("%s", o->ancestor);
+               base_name = opt->ancestor == NULL ? NULL :
+                       mkpathdup("%s", opt->ancestor);
                name1 = mkpathdup("%s", branch1);
                name2 = mkpathdup("%s", branch2);
        }
 
-       read_mmblob(&orig, &one->oid);
+       read_mmblob(&orig, &o->oid);
        read_mmblob(&src1, &a->oid);
        read_mmblob(&src2, &b->oid);
 
        merge_status = ll_merge(result_buf, a->path, &orig, base_name,
                                &src1, name1, &src2, name2,
-                               o->repo->index, &ll_opts);
+                               opt->repo->index, &ll_opts);
 
        free(base_name);
        free(name1);
@@ -1184,7 +1143,12 @@ static void print_commit(struct commit *commit)
        strbuf_release(&sb);
 }
 
-static int merge_submodule(struct merge_options *o,
+static int is_valid(const struct diff_filespec *dfs)
+{
+       return dfs->mode != 0 && !is_null_oid(&dfs->oid);
+}
+
+static int merge_submodule(struct merge_options *opt,
                           struct object_id *result, const char *path,
                           const struct object_id *base, const struct object_id *a,
                           const struct object_id *b)
@@ -1194,7 +1158,7 @@ static int merge_submodule(struct merge_options *o,
        struct object_array merges;
 
        int i;
-       int search = !o->call_depth;
+       int search = !opt->call_depth;
 
        /* store a in result in case we fail */
        oidcpy(result, a);
@@ -1208,32 +1172,32 @@ static int merge_submodule(struct merge_options *o,
                return 0;
 
        if (add_submodule_odb(path)) {
-               output(o, 1, _("Failed to merge submodule %s (not checked out)"), path);
+               output(opt, 1, _("Failed to merge submodule %s (not checked out)"), path);
                return 0;
        }
 
-       if (!(commit_base = lookup_commit_reference(o->repo, base)) ||
-           !(commit_a = lookup_commit_reference(o->repo, a)) ||
-           !(commit_b = lookup_commit_reference(o->repo, b))) {
-               output(o, 1, _("Failed to merge submodule %s (commits not present)"), path);
+       if (!(commit_base = lookup_commit_reference(opt->repo, base)) ||
+           !(commit_a = lookup_commit_reference(opt->repo, a)) ||
+           !(commit_b = lookup_commit_reference(opt->repo, b))) {
+               output(opt, 1, _("Failed to merge submodule %s (commits not present)"), path);
                return 0;
        }
 
        /* check whether both changes are forward */
        if (!in_merge_bases(commit_base, commit_a) ||
            !in_merge_bases(commit_base, commit_b)) {
-               output(o, 1, _("Failed to merge submodule %s (commits don't follow merge-base)"), path);
+               output(opt, 1, _("Failed to merge submodule %s (commits don't follow merge-base)"), path);
                return 0;
        }
 
        /* Case #1: a is contained in b or vice versa */
        if (in_merge_bases(commit_a, commit_b)) {
                oidcpy(result, b);
-               if (show(o, 3)) {
-                       output(o, 3, _("Fast-forwarding submodule %s to the following commit:"), path);
-                       output_commit_title(o, commit_b);
-               } else if (show(o, 2))
-                       output(o, 2, _("Fast-forwarding submodule %s"), path);
+               if (show(opt, 3)) {
+                       output(opt, 3, _("Fast-forwarding submodule %s to the following commit:"), path);
+                       output_commit_title(opt, commit_b);
+               } else if (show(opt, 2))
+                       output(opt, 2, _("Fast-forwarding submodule %s"), path);
                else
                        ; /* no output */
 
@@ -1241,11 +1205,11 @@ static int merge_submodule(struct merge_options *o,
        }
        if (in_merge_bases(commit_b, commit_a)) {
                oidcpy(result, a);
-               if (show(o, 3)) {
-                       output(o, 3, _("Fast-forwarding submodule %s to the following commit:"), path);
-                       output_commit_title(o, commit_a);
-               } else if (show(o, 2))
-                       output(o, 2, _("Fast-forwarding submodule %s"), path);
+               if (show(opt, 3)) {
+                       output(opt, 3, _("Fast-forwarding submodule %s to the following commit:"), path);
+                       output_commit_title(opt, commit_a);
+               } else if (show(opt, 2))
+                       output(opt, 2, _("Fast-forwarding submodule %s"), path);
                else
                        ; /* no output */
 
@@ -1264,18 +1228,18 @@ static int merge_submodule(struct merge_options *o,
                return 0;
 
        /* find commit which merges them */
-       parent_count = find_first_merges(o->repo, &merges, path,
+       parent_count = find_first_merges(opt->repo, &merges, path,
                                         commit_a, commit_b);
        switch (parent_count) {
        case 0:
-               output(o, 1, _("Failed to merge submodule %s (merge following commits not found)"), path);
+               output(opt, 1, _("Failed to merge submodule %s (merge following commits not found)"), path);
                break;
 
        case 1:
-               output(o, 1, _("Failed to merge submodule %s (not fast-forward)"), path);
-               output(o, 2, _("Found a possible merge resolution for the submodule:\n"));
+               output(opt, 1, _("Failed to merge submodule %s (not fast-forward)"), path);
+               output(opt, 2, _("Found a possible merge resolution for the submodule:\n"));
                print_commit((struct commit *) merges.objects[0].item);
-               output(o, 2, _(
+               output(opt, 2, _(
                       "If this is correct simply add it to the index "
                       "for example\n"
                       "by using:\n\n"
@@ -1285,7 +1249,7 @@ static int merge_submodule(struct merge_options *o,
                break;
 
        default:
-               output(o, 1, _("Failed to merge submodule %s (multiple merges found)"), path);
+               output(opt, 1, _("Failed to merge submodule %s (multiple merges found)"), path);
                for (i = 0; i < merges.nr; i++)
                        print_commit((struct commit *) merges.objects[i].item);
        }
@@ -1294,8 +1258,8 @@ static int merge_submodule(struct merge_options *o,
        return 0;
 }
 
-static int merge_mode_and_contents(struct merge_options *o,
-                                  const struct diff_filespec *one,
+static int merge_mode_and_contents(struct merge_options *opt,
+                                  const struct diff_filespec *o,
                                   const struct diff_filespec *a,
                                   const struct diff_filespec *b,
                                   const char *filename,
@@ -1304,13 +1268,13 @@ static int merge_mode_and_contents(struct merge_options *o,
                                   const int extra_marker_size,
                                   struct merge_file_info *result)
 {
-       if (o->branch1 != branch1) {
+       if (opt->branch1 != branch1) {
                /*
                 * It's weird getting a reverse merge with HEAD on the bottom
                 * side of the conflict markers and the other branch on the
                 * top.  Fix that.
                 */
-               return merge_mode_and_contents(o, one, b, a,
+               return merge_mode_and_contents(opt, o, b, a,
                                               filename,
                                               branch2, branch1,
                                               extra_marker_size, result);
@@ -1322,48 +1286,48 @@ static int merge_mode_and_contents(struct merge_options *o,
        if ((S_IFMT & a->mode) != (S_IFMT & b->mode)) {
                result->clean = 0;
                if (S_ISREG(a->mode)) {
-                       result->mode = a->mode;
-                       oidcpy(&result->oid, &a->oid);
+                       result->blob.mode = a->mode;
+                       oidcpy(&result->blob.oid, &a->oid);
                } else {
-                       result->mode = b->mode;
-                       oidcpy(&result->oid, &b->oid);
+                       result->blob.mode = b->mode;
+                       oidcpy(&result->blob.oid, &b->oid);
                }
        } else {
-               if (!oid_eq(&a->oid, &one->oid) && !oid_eq(&b->oid, &one->oid))
+               if (!oid_eq(&a->oid, &o->oid) && !oid_eq(&b->oid, &o->oid))
                        result->merge = 1;
 
                /*
                 * Merge modes
                 */
-               if (a->mode == b->mode || a->mode == one->mode)
-                       result->mode = b->mode;
+               if (a->mode == b->mode || a->mode == o->mode)
+                       result->blob.mode = b->mode;
                else {
-                       result->mode = a->mode;
-                       if (b->mode != one->mode) {
+                       result->blob.mode = a->mode;
+                       if (b->mode != o->mode) {
                                result->clean = 0;
                                result->merge = 1;
                        }
                }
 
-               if (oid_eq(&a->oid, &b->oid) || oid_eq(&a->oid, &one->oid))
-                       oidcpy(&result->oid, &b->oid);
-               else if (oid_eq(&b->oid, &one->oid))
-                       oidcpy(&result->oid, &a->oid);
+               if (oid_eq(&a->oid, &b->oid) || oid_eq(&a->oid, &o->oid))
+                       oidcpy(&result->blob.oid, &b->oid);
+               else if (oid_eq(&b->oid, &o->oid))
+                       oidcpy(&result->blob.oid, &a->oid);
                else if (S_ISREG(a->mode)) {
                        mmbuffer_t result_buf;
                        int ret = 0, merge_status;
 
-                       merge_status = merge_3way(o, &result_buf, one, a, b,
+                       merge_status = merge_3way(opt, &result_buf, o, a, b,
                                                  branch1, branch2,
                                                  extra_marker_size);
 
                        if ((merge_status < 0) || !result_buf.ptr)
-                               ret = err(o, _("Failed to execute internal merge"));
+                               ret = err(opt, _("Failed to execute internal merge"));
 
                        if (!ret &&
                            write_object_file(result_buf.ptr, result_buf.size,
-                                             blob_type, &result->oid))
-                               ret = err(o, _("Unable to add %s to database"),
+                                             blob_type, &result->blob.oid))
+                               ret = err(opt, _("Unable to add %s to database"),
                                          a->path);
 
                        free(result_buf.ptr);
@@ -1371,23 +1335,23 @@ static int merge_mode_and_contents(struct merge_options *o,
                                return ret;
                        result->clean = (merge_status == 0);
                } else if (S_ISGITLINK(a->mode)) {
-                       result->clean = merge_submodule(o, &result->oid,
-                                                       one->path,
-                                                       &one->oid,
+                       result->clean = merge_submodule(opt, &result->blob.oid,
+                                                       o->path,
+                                                       &o->oid,
                                                        &a->oid,
                                                        &b->oid);
                } else if (S_ISLNK(a->mode)) {
-                       switch (o->recursive_variant) {
+                       switch (opt->recursive_variant) {
                        case MERGE_RECURSIVE_NORMAL:
-                               oidcpy(&result->oid, &a->oid);
+                               oidcpy(&result->blob.oid, &a->oid);
                                if (!oid_eq(&a->oid, &b->oid))
                                        result->clean = 0;
                                break;
                        case MERGE_RECURSIVE_OURS:
-                               oidcpy(&result->oid, &a->oid);
+                               oidcpy(&result->blob.oid, &a->oid);
                                break;
                        case MERGE_RECURSIVE_THEIRS:
-                               oidcpy(&result->oid, &b->oid);
+                               oidcpy(&result->blob.oid, &b->oid);
                                break;
                        }
                } else
@@ -1395,14 +1359,13 @@ static int merge_mode_and_contents(struct merge_options *o,
        }
 
        if (result->merge)
-               output(o, 2, _("Auto-merging %s"), filename);
+               output(opt, 2, _("Auto-merging %s"), filename);
 
        return 0;
 }
 
-static int handle_rename_via_dir(struct merge_options *o,
-                                struct diff_filepair *pair,
-                                const char *rename_branch)
+static int handle_rename_via_dir(struct merge_options *opt,
+                                struct rename_conflict_info *ci)
 {
        /*
         * Handle file adds that need to be renamed due to directory rename
@@ -1410,38 +1373,47 @@ static int handle_rename_via_dir(struct merge_options *o,
         * there is no content merge to do; just move the file into the
         * desired final location.
         */
-       const struct diff_filespec *dest = pair->two;
+       const struct rename *ren = ci->ren1;
+       const struct diff_filespec *dest = ren->pair->two;
+       char *file_path = dest->path;
+       int mark_conflicted = (opt->detect_directory_renames == 1);
+       assert(ren->dir_rename_original_dest);
 
-       if (!o->call_depth && would_lose_untracked(o, dest->path)) {
-               char *alt_path = unique_path(o, dest->path, rename_branch);
+       if (!opt->call_depth && would_lose_untracked(opt, dest->path)) {
+               mark_conflicted = 1;
+               file_path = unique_path(opt, dest->path, ren->branch);
+               output(opt, 1, _("Error: Refusing to lose untracked file at %s; "
+                                "writing to %s instead."),
+                      dest->path, file_path);
+       }
 
-               output(o, 1, _("Error: Refusing to lose untracked file at %s; "
-                              "writing to %s instead."),
-                      dest->path, alt_path);
+       if (mark_conflicted) {
                /*
-                * Write the file in worktree at alt_path, but not in the
-                * index.  Instead, write to dest->path for the index but
-                * only at the higher appropriate stage.
+                * Write the file in worktree at file_path.  In the index,
+                * only record the file at dest->path in the appropriate
+                * higher stage.
                 */
-               if (update_file(o, 0, &dest->oid, dest->mode, alt_path))
+               if (update_file(opt, 0, dest, file_path))
+                       return -1;
+               if (file_path != dest->path)
+                       free(file_path);
+               if (update_stages(opt, dest->path, NULL,
+                                 ren->branch == opt->branch1 ? dest : NULL,
+                                 ren->branch == opt->branch1 ? NULL : dest))
                        return -1;
-               free(alt_path);
-               return update_stages(o, dest->path, NULL,
-                                    rename_branch == o->branch1 ? dest : NULL,
-                                    rename_branch == o->branch1 ? NULL : dest);
+               return 0; /* not clean, but conflicted */
+       } else {
+               /* Update dest->path both in index and in worktree */
+               if (update_file(opt, 1, dest, dest->path))
+                       return -1;
+               return 1; /* clean */
        }
-
-       /* Update dest->path both in index and in worktree */
-       if (update_file(o, 1, &dest->oid, dest->mode, dest->path))
-               return -1;
-       return 0;
 }
 
-static int handle_change_delete(struct merge_options *o,
+static int handle_change_delete(struct merge_options *opt,
                                const char *path, const char *old_path,
-                               const struct object_id *o_oid, int o_mode,
-                               const struct object_id *changed_oid,
-                               int changed_mode,
+                               const struct diff_filespec *o,
+                               const struct diff_filespec *changed,
                                const char *change_branch,
                                const char *delete_branch,
                                const char *change, const char *change_past)
@@ -1450,20 +1422,20 @@ static int handle_change_delete(struct merge_options *o,
        const char *update_path = path;
        int ret = 0;
 
-       if (dir_in_way(o->repo->index, path, !o->call_depth, 0) ||
-           (!o->call_depth && would_lose_untracked(o, path))) {
-               update_path = alt_path = unique_path(o, path, change_branch);
+       if (dir_in_way(opt->repo->index, path, !opt->call_depth, 0) ||
+           (!opt->call_depth && would_lose_untracked(opt, path))) {
+               update_path = alt_path = unique_path(opt, path, change_branch);
        }
 
-       if (o->call_depth) {
+       if (opt->call_depth) {
                /*
                 * We cannot arbitrarily accept either a_sha or b_sha as
                 * correct; since there is no true "middle point" between
                 * them, simply reuse the base version for virtual merge base.
                 */
-               ret = remove_file_from_index(o->repo->index, path);
+               ret = remove_file_from_index(opt->repo->index, path);
                if (!ret)
-                       ret = update_file(o, 0, o_oid, o_mode, update_path);
+                       ret = update_file(opt, 0, o, update_path);
        } else {
                /*
                 * Despite the four nearly duplicate messages and argument
@@ -1482,24 +1454,24 @@ static int handle_change_delete(struct merge_options *o,
                 */
                if (!alt_path) {
                        if (!old_path) {
-                               output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+                               output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s "
                                       "and %s in %s. Version %s of %s left in tree."),
                                       change, path, delete_branch, change_past,
                                       change_branch, change_branch, path);
                        } else {
-                               output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+                               output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s "
                                       "and %s to %s in %s. Version %s of %s left in tree."),
                                       change, old_path, delete_branch, change_past, path,
                                       change_branch, change_branch, path);
                        }
                } else {
                        if (!old_path) {
-                               output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+                               output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s "
                                       "and %s in %s. Version %s of %s left in tree at %s."),
                                       change, path, delete_branch, change_past,
                                       change_branch, change_branch, path, alt_path);
                        } else {
-                               output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
+                               output(opt, 1, _("CONFLICT (%s/delete): %s deleted in %s "
                                       "and %s to %s in %s. Version %s of %s left in tree at %s."),
                                       change, old_path, delete_branch, change_past, path,
                                       change_branch, change_branch, path, alt_path);
@@ -1507,142 +1479,127 @@ static int handle_change_delete(struct merge_options *o,
                }
                /*
                 * No need to call update_file() on path when change_branch ==
-                * o->branch1 && !alt_path, since that would needlessly touch
+                * opt->branch1 && !alt_path, since that would needlessly touch
                 * path.  We could call update_file_flags() with update_cache=0
                 * and update_wd=0, but that's a no-op.
                 */
-               if (change_branch != o->branch1 || alt_path)
-                       ret = update_file(o, 0, changed_oid, changed_mode, update_path);
+               if (change_branch != opt->branch1 || alt_path)
+                       ret = update_file(opt, 0, changed, update_path);
        }
        free(alt_path);
 
        return ret;
 }
 
-static int handle_rename_delete(struct merge_options *o,
-                               struct diff_filepair *pair,
-                               const char *rename_branch,
-                               const char *delete_branch)
+static int handle_rename_delete(struct merge_options *opt,
+                               struct rename_conflict_info *ci)
 {
-       const struct diff_filespec *orig = pair->one;
-       const struct diff_filespec *dest = pair->two;
-
-       if (handle_change_delete(o,
-                                o->call_depth ? orig->path : dest->path,
-                                o->call_depth ? NULL : orig->path,
-                                &orig->oid, orig->mode,
-                                &dest->oid, dest->mode,
+       const struct rename *ren = ci->ren1;
+       const struct diff_filespec *orig = ren->pair->one;
+       const struct diff_filespec *dest = ren->pair->two;
+       const char *rename_branch = ren->branch;
+       const char *delete_branch = (opt->branch1 == ren->branch ?
+                                    opt->branch2 : opt->branch1);
+
+       if (handle_change_delete(opt,
+                                opt->call_depth ? orig->path : dest->path,
+                                opt->call_depth ? NULL : orig->path,
+                                orig, dest,
                                 rename_branch, delete_branch,
                                 _("rename"), _("renamed")))
                return -1;
 
-       if (o->call_depth)
-               return remove_file_from_index(o->repo->index, dest->path);
+       if (opt->call_depth)
+               return remove_file_from_index(opt->repo->index, dest->path);
        else
-               return update_stages(o, dest->path, NULL,
-                                    rename_branch == o->branch1 ? dest : NULL,
-                                    rename_branch == o->branch1 ? NULL : dest);
+               return update_stages(opt, dest->path, NULL,
+                                    rename_branch == opt->branch1 ? dest : NULL,
+                                    rename_branch == opt->branch1 ? NULL : dest);
 }
 
-static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
-                                                struct stage_data *entry,
-                                                int stage)
-{
-       struct object_id *oid = &entry->stages[stage].oid;
-       unsigned mode = entry->stages[stage].mode;
-       if (mode == 0 || is_null_oid(oid))
-               return NULL;
-       oidcpy(&target->oid, oid);
-       target->mode = mode;
-       return target;
-}
-
-static int handle_file_collision(struct merge_options *o,
+static int handle_file_collision(struct merge_options *opt,
                                 const char *collide_path,
                                 const char *prev_path1,
                                 const char *prev_path2,
                                 const char *branch1, const char *branch2,
-                                const struct object_id *a_oid,
-                                unsigned int a_mode,
-                                const struct object_id *b_oid,
-                                unsigned int b_mode)
+                                struct diff_filespec *a,
+                                struct diff_filespec *b)
 {
        struct merge_file_info mfi;
-       struct diff_filespec null, a, b;
+       struct diff_filespec null;
        char *alt_path = NULL;
        const char *update_path = collide_path;
 
        /*
         * It's easiest to get the correct things into stage 2 and 3, and
         * to make sure that the content merge puts HEAD before the other
-        * branch if we just ensure that branch1 == o->branch1.  So, simply
+        * branch if we just ensure that branch1 == opt->branch1.  So, simply
         * flip arguments around if we don't have that.
         */
-       if (branch1 != o->branch1) {
-               return handle_file_collision(o, collide_path,
+       if (branch1 != opt->branch1) {
+               return handle_file_collision(opt, collide_path,
                                             prev_path2, prev_path1,
                                             branch2, branch1,
-                                            b_oid, b_mode,
-                                            a_oid, a_mode);
+                                            b, a);
        }
 
        /*
         * In the recursive case, we just opt to undo renames
         */
-       if (o->call_depth && (prev_path1 || prev_path2)) {
-               /* Put first file (a_oid, a_mode) in its original spot */
+       if (opt->call_depth && (prev_path1 || prev_path2)) {
+               /* Put first file (a->oid, a->mode) in its original spot */
                if (prev_path1) {
-                       if (update_file(o, 1, a_oid, a_mode, prev_path1))
+                       if (update_file(opt, 1, a, prev_path1))
                                return -1;
                } else {
-                       if (update_file(o, 1, a_oid, a_mode, collide_path))
+                       if (update_file(opt, 1, a, collide_path))
                                return -1;
                }
 
-               /* Put second file (b_oid, b_mode) in its original spot */
+               /* Put second file (b->oid, b->mode) in its original spot */
                if (prev_path2) {
-                       if (update_file(o, 1, b_oid, b_mode, prev_path2))
+                       if (update_file(opt, 1, b, prev_path2))
                                return -1;
                } else {
-                       if (update_file(o, 1, b_oid, b_mode, collide_path))
+                       if (update_file(opt, 1, b, collide_path))
                                return -1;
                }
 
                /* Don't leave something at collision path if unrenaming both */
                if (prev_path1 && prev_path2)
-                       remove_file(o, 1, collide_path, 0);
+                       remove_file(opt, 1, collide_path, 0);
 
                return 0;
        }
 
        /* Remove rename sources if rename/add or rename/rename(2to1) */
        if (prev_path1)
-               remove_file(o, 1, prev_path1,
-                           o->call_depth || would_lose_untracked(o, prev_path1));
+               remove_file(opt, 1, prev_path1,
+                           opt->call_depth || would_lose_untracked(opt, prev_path1));
        if (prev_path2)
-               remove_file(o, 1, prev_path2,
-                           o->call_depth || would_lose_untracked(o, prev_path2));
+               remove_file(opt, 1, prev_path2,
+                           opt->call_depth || would_lose_untracked(opt, prev_path2));
 
        /*
         * Remove the collision path, if it wouldn't cause dirty contents
         * or an untracked file to get lost.  We'll either overwrite with
         * merged contents, or just write out to differently named files.
         */
-       if (was_dirty(o, collide_path)) {
-               output(o, 1, _("Refusing to lose dirty file at %s"),
+       if (was_dirty(opt, collide_path)) {
+               output(opt, 1, _("Refusing to lose dirty file at %s"),
                       collide_path);
-               update_path = alt_path = unique_path(o, collide_path, "merged");
-       } else if (would_lose_untracked(o, collide_path)) {
+               update_path = alt_path = unique_path(opt, collide_path, "merged");
+       } else if (would_lose_untracked(opt, collide_path)) {
                /*
                 * Only way we get here is if both renames were from
                 * a directory rename AND user had an untracked file
                 * at the location where both files end up after the
                 * two directory renames.  See testcase 10d of t6043.
                 */
-               output(o, 1, _("Refusing to lose untracked file at "
+               output(opt, 1, _("Refusing to lose untracked file at "
                               "%s, even though it's in the way."),
                       collide_path);
-               update_path = alt_path = unique_path(o, collide_path, "merged");
+               update_path = alt_path = unique_path(opt, collide_path, "merged");
        } else {
                /*
                 * FIXME: It's possible that the two files are identical
@@ -1654,30 +1611,22 @@ static int handle_file_collision(struct merge_options *o,
                 * merge-recursive interoperate anyway, so punting for
                 * now...
                 */
-               remove_file(o, 0, collide_path, 0);
+               remove_file(opt, 0, collide_path, 0);
        }
 
        /* Store things in diff_filespecs for functions that need it */
-       memset(&a, 0, sizeof(struct diff_filespec));
-       memset(&b, 0, sizeof(struct diff_filespec));
-       null.path = a.path = b.path = (char *)collide_path;
+       null.path = (char *)collide_path;
        oidcpy(&null.oid, &null_oid);
        null.mode = 0;
-       oidcpy(&a.oid, a_oid);
-       a.mode = a_mode;
-       a.oid_valid = 1;
-       oidcpy(&b.oid, b_oid);
-       b.mode = b_mode;
-       b.oid_valid = 1;
-
-       if (merge_mode_and_contents(o, &null, &a, &b, collide_path,
-                                   branch1, branch2, o->call_depth * 2, &mfi))
+
+       if (merge_mode_and_contents(opt, &null, a, b, collide_path,
+                                   branch1, branch2, opt->call_depth * 2, &mfi))
                return -1;
        mfi.clean &= !alt_path;
-       if (update_file(o, mfi.clean, &mfi.oid, mfi.mode, update_path))
+       if (update_file(opt, mfi.clean, &mfi.blob, update_path))
                return -1;
-       if (!mfi.clean && !o->call_depth &&
-           update_stages(o, collide_path, NULL, &a, &b))
+       if (!mfi.clean && !opt->call_depth &&
+           update_stages(opt, collide_path, NULL, a, b))
                return -1;
        free(alt_path);
        /*
@@ -1690,52 +1639,58 @@ static int handle_file_collision(struct merge_options *o,
        return mfi.clean;
 }
 
-static int handle_rename_add(struct merge_options *o,
+static int handle_rename_add(struct merge_options *opt,
                             struct rename_conflict_info *ci)
 {
        /* a was renamed to c, and a separate c was added. */
-       struct diff_filespec *a = ci->pair1->one;
-       struct diff_filespec *c = ci->pair1->two;
+       struct diff_filespec *a = ci->ren1->pair->one;
+       struct diff_filespec *c = ci->ren1->pair->two;
        char *path = c->path;
        char *prev_path_desc;
        struct merge_file_info mfi;
 
-       int other_stage = (ci->branch1 == o->branch1 ? 3 : 2);
+       const char *rename_branch = ci->ren1->branch;
+       const char *add_branch = (opt->branch1 == rename_branch ?
+                                 opt->branch2 : opt->branch1);
+       int other_stage = (ci->ren1->branch == opt->branch1 ? 3 : 2);
 
-       output(o, 1, _("CONFLICT (rename/add): "
+       output(opt, 1, _("CONFLICT (rename/add): "
               "Rename %s->%s in %s.  Added %s in %s"),
-              a->path, c->path, ci->branch1,
-              c->path, ci->branch2);
+              a->path, c->path, rename_branch,
+              c->path, add_branch);
 
        prev_path_desc = xstrfmt("version of %s from %s", path, a->path);
-       if (merge_mode_and_contents(o, a, c, &ci->ren1_other, prev_path_desc,
-                                   o->branch1, o->branch2,
-                                   1 + o->call_depth * 2, &mfi))
+       ci->ren1->src_entry->stages[other_stage].path = a->path;
+       if (merge_mode_and_contents(opt, a, c,
+                                   &ci->ren1->src_entry->stages[other_stage],
+                                   prev_path_desc,
+                                   opt->branch1, opt->branch2,
+                                   1 + opt->call_depth * 2, &mfi))
                return -1;
        free(prev_path_desc);
 
-       return handle_file_collision(o,
+       ci->ren1->dst_entry->stages[other_stage].path = mfi.blob.path = c->path;
+       return handle_file_collision(opt,
                                     c->path, a->path, NULL,
-                                    ci->branch1, ci->branch2,
-                                    &mfi.oid, mfi.mode,
-                                    &ci->dst_entry1->stages[other_stage].oid,
-                                    ci->dst_entry1->stages[other_stage].mode);
+                                    rename_branch, add_branch,
+                                    &mfi.blob,
+                                    &ci->ren1->dst_entry->stages[other_stage]);
 }
 
-static char *find_path_for_conflict(struct merge_options *o,
+static char *find_path_for_conflict(struct merge_options *opt,
                                    const char *path,
                                    const char *branch1,
                                    const char *branch2)
 {
        char *new_path = NULL;
-       if (dir_in_way(o->repo->index, path, !o->call_depth, 0)) {
-               new_path = unique_path(o, path, branch1);
-               output(o, 1, _("%s is a directory in %s adding "
+       if (dir_in_way(opt->repo->index, path, !opt->call_depth, 0)) {
+               new_path = unique_path(opt, path, branch1);
+               output(opt, 1, _("%s is a directory in %s adding "
                               "as %s instead"),
                       path, branch2, new_path);
-       } else if (would_lose_untracked(o, path)) {
-               new_path = unique_path(o, path, branch1);
-               output(o, 1, _("Refusing to lose untracked file"
+       } else if (would_lose_untracked(opt, path)) {
+               new_path = unique_path(opt, path, branch1);
+               output(opt, 1, _("Refusing to lose untracked file"
                               " at %s; adding as %s instead"),
                       path, new_path);
        }
@@ -1743,41 +1698,40 @@ static char *find_path_for_conflict(struct merge_options *o,
        return new_path;
 }
 
-static int handle_rename_rename_1to2(struct merge_options *o,
+static int handle_rename_rename_1to2(struct merge_options *opt,
                                     struct rename_conflict_info *ci)
 {
        /* One file was renamed in both branches, but to different names. */
        struct merge_file_info mfi;
-       struct diff_filespec other;
        struct diff_filespec *add;
-       struct diff_filespec *one = ci->pair1->one;
-       struct diff_filespec *a = ci->pair1->two;
-       struct diff_filespec *b = ci->pair2->two;
+       struct diff_filespec *o = ci->ren1->pair->one;
+       struct diff_filespec *a = ci->ren1->pair->two;
+       struct diff_filespec *b = ci->ren2->pair->two;
        char *path_desc;
 
-       output(o, 1, _("CONFLICT (rename/rename): "
+       output(opt, 1, _("CONFLICT (rename/rename): "
               "Rename \"%s\"->\"%s\" in branch \"%s\" "
               "rename \"%s\"->\"%s\" in \"%s\"%s"),
-              one->path, a->path, ci->branch1,
-              one->path, b->path, ci->branch2,
-              o->call_depth ? _(" (left unresolved)") : "");
+              o->path, a->path, ci->ren1->branch,
+              o->path, b->path, ci->ren2->branch,
+              opt->call_depth ? _(" (left unresolved)") : "");
 
        path_desc = xstrfmt("%s and %s, both renamed from %s",
-                           a->path, b->path, one->path);
-       if (merge_mode_and_contents(o, one, a, b, path_desc,
-                                   ci->branch1, ci->branch2,
-                                   o->call_depth * 2, &mfi))
+                           a->path, b->path, o->path);
+       if (merge_mode_and_contents(opt, o, a, b, path_desc,
+                                   ci->ren1->branch, ci->ren2->branch,
+                                   opt->call_depth * 2, &mfi))
                return -1;
        free(path_desc);
 
-       if (o->call_depth) {
+       if (opt->call_depth) {
                /*
                 * FIXME: For rename/add-source conflicts (if we could detect
                 * such), this is wrong.  We should instead find a unique
                 * pathname and then either rename the add-source file to that
                 * unique path, or use that unique path instead of src here.
                 */
-               if (update_file(o, 0, &mfi.oid, mfi.mode, one->path))
+               if (update_file(opt, 0, &mfi.blob, o->path))
                        return -1;
 
                /*
@@ -1788,61 +1742,65 @@ static int handle_rename_rename_1to2(struct merge_options *o,
                 * such cases, we should keep the added file around,
                 * resolving the conflict at that path in its favor.
                 */
-               add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
-               if (add) {
-                       if (update_file(o, 0, &add->oid, add->mode, a->path))
+               add = &ci->ren1->dst_entry->stages[2 ^ 1];
+               if (is_valid(add)) {
+                       if (update_file(opt, 0, add, a->path))
                                return -1;
                }
                else
-                       remove_file_from_index(o->repo->index, a->path);
-               add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
-               if (add) {
-                       if (update_file(o, 0, &add->oid, add->mode, b->path))
+                       remove_file_from_index(opt->repo->index, a->path);
+               add = &ci->ren2->dst_entry->stages[3 ^ 1];
+               if (is_valid(add)) {
+                       if (update_file(opt, 0, add, b->path))
                                return -1;
                }
                else
-                       remove_file_from_index(o->repo->index, b->path);
+                       remove_file_from_index(opt->repo->index, b->path);
        } else {
                /*
                 * For each destination path, we need to see if there is a
                 * rename/add collision.  If not, we can write the file out
                 * to the specified location.
                 */
-               add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
-               if (add) {
-                       if (handle_file_collision(o, a->path,
+               add = &ci->ren1->dst_entry->stages[2 ^ 1];
+               if (is_valid(add)) {
+                       add->path = mfi.blob.path = a->path;
+                       if (handle_file_collision(opt, a->path,
                                                  NULL, NULL,
-                                                 ci->branch1, ci->branch2,
-                                                 &mfi.oid, mfi.mode,
-                                                 &add->oid, add->mode) < 0)
+                                                 ci->ren1->branch,
+                                                 ci->ren2->branch,
+                                                 &mfi.blob, add) < 0)
                                return -1;
                } else {
-                       char *new_path = find_path_for_conflict(o, a->path,
-                                                               ci->branch1,
-                                                               ci->branch2);
-                       if (update_file(o, 0, &mfi.oid, mfi.mode, new_path ? new_path : a->path))
+                       char *new_path = find_path_for_conflict(opt, a->path,
+                                                               ci->ren1->branch,
+                                                               ci->ren2->branch);
+                       if (update_file(opt, 0, &mfi.blob,
+                                       new_path ? new_path : a->path))
                                return -1;
                        free(new_path);
-                       if (update_stages(o, a->path, NULL, a, NULL))
+                       if (update_stages(opt, a->path, NULL, a, NULL))
                                return -1;
                }
 
-               add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
-               if (add) {
-                       if (handle_file_collision(o, b->path,
+               add = &ci->ren2->dst_entry->stages[3 ^ 1];
+               if (is_valid(add)) {
+                       add->path = mfi.blob.path = b->path;
+                       if (handle_file_collision(opt, b->path,
                                                  NULL, NULL,
-                                                 ci->branch1, ci->branch2,
-                                                 &add->oid, add->mode,
-                                                 &mfi.oid, mfi.mode) < 0)
+                                                 ci->ren1->branch,
+                                                 ci->ren2->branch,
+                                                 add, &mfi.blob) < 0)
                                return -1;
                } else {
-                       char *new_path = find_path_for_conflict(o, b->path,
-                                                               ci->branch2,
-                                                               ci->branch1);
-                       if (update_file(o, 0, &mfi.oid, mfi.mode, new_path ? new_path : b->path))
+                       char *new_path = find_path_for_conflict(opt, b->path,
+                                                               ci->ren2->branch,
+                                                               ci->ren1->branch);
+                       if (update_file(opt, 0, &mfi.blob,
+                                       new_path ? new_path : b->path))
                                return -1;
                        free(new_path);
-                       if (update_stages(o, b->path, NULL, NULL, b))
+                       if (update_stages(opt, b->path, NULL, NULL, b))
                                return -1;
                }
        }
@@ -1850,58 +1808,68 @@ static int handle_rename_rename_1to2(struct merge_options *o,
        return 0;
 }
 
-static int handle_rename_rename_2to1(struct merge_options *o,
+static int handle_rename_rename_2to1(struct merge_options *opt,
                                     struct rename_conflict_info *ci)
 {
        /* Two files, a & b, were renamed to the same thing, c. */
-       struct diff_filespec *a = ci->pair1->one;
-       struct diff_filespec *b = ci->pair2->one;
-       struct diff_filespec *c1 = ci->pair1->two;
-       struct diff_filespec *c2 = ci->pair2->two;
+       struct diff_filespec *a = ci->ren1->pair->one;
+       struct diff_filespec *b = ci->ren2->pair->one;
+       struct diff_filespec *c1 = ci->ren1->pair->two;
+       struct diff_filespec *c2 = ci->ren2->pair->two;
        char *path = c1->path; /* == c2->path */
        char *path_side_1_desc;
        char *path_side_2_desc;
        struct merge_file_info mfi_c1;
        struct merge_file_info mfi_c2;
+       int ostage1, ostage2;
 
-       output(o, 1, _("CONFLICT (rename/rename): "
+       output(opt, 1, _("CONFLICT (rename/rename): "
               "Rename %s->%s in %s. "
               "Rename %s->%s in %s"),
-              a->path, c1->path, ci->branch1,
-              b->path, c2->path, ci->branch2);
+              a->path, c1->path, ci->ren1->branch,
+              b->path, c2->path, ci->ren2->branch);
 
        path_side_1_desc = xstrfmt("version of %s from %s", path, a->path);
        path_side_2_desc = xstrfmt("version of %s from %s", path, b->path);
-       if (merge_mode_and_contents(o, a, c1, &ci->ren1_other, path_side_1_desc,
-                                   o->branch1, o->branch2,
-                                   1 + o->call_depth * 2, &mfi_c1) ||
-           merge_mode_and_contents(o, b, &ci->ren2_other, c2, path_side_2_desc,
-                                   o->branch1, o->branch2,
-                                   1 + o->call_depth * 2, &mfi_c2))
+       ostage1 = ci->ren1->branch == opt->branch1 ? 3 : 2;
+       ostage2 = ostage1 ^ 1;
+       ci->ren1->src_entry->stages[ostage1].path = a->path;
+       ci->ren2->src_entry->stages[ostage2].path = b->path;
+       if (merge_mode_and_contents(opt, a, c1,
+                                   &ci->ren1->src_entry->stages[ostage1],
+                                   path_side_1_desc,
+                                   opt->branch1, opt->branch2,
+                                   1 + opt->call_depth * 2, &mfi_c1) ||
+           merge_mode_and_contents(opt, b,
+                                   &ci->ren2->src_entry->stages[ostage2],
+                                   c2, path_side_2_desc,
+                                   opt->branch1, opt->branch2,
+                                   1 + opt->call_depth * 2, &mfi_c2))
                return -1;
        free(path_side_1_desc);
        free(path_side_2_desc);
+       mfi_c1.blob.path = path;
+       mfi_c2.blob.path = path;
 
-       return handle_file_collision(o, path, a->path, b->path,
-                                    ci->branch1, ci->branch2,
-                                    &mfi_c1.oid, mfi_c1.mode,
-                                    &mfi_c2.oid, mfi_c2.mode);
+       return handle_file_collision(opt, path, a->path, b->path,
+                                    ci->ren1->branch, ci->ren2->branch,
+                                    &mfi_c1.blob, &mfi_c2.blob);
 }
 
 /*
  * Get the diff_filepairs changed between o_tree and tree.
  */
-static struct diff_queue_struct *get_diffpairs(struct merge_options *o,
+static struct diff_queue_struct *get_diffpairs(struct merge_options *opt,
                                               struct tree *o_tree,
                                               struct tree *tree)
 {
        struct diff_queue_struct *ret;
        struct diff_options opts;
 
-       repo_diff_setup(o->repo, &opts);
+       repo_diff_setup(opt->repo, &opts);
        opts.flags.recursive = 1;
        opts.flags.rename_empty = 0;
-       opts.detect_rename = merge_detect_rename(o);
+       opts.detect_rename = merge_detect_rename(opt);
        /*
         * We do not have logic to handle the detection of copies.  In
         * fact, it may not even make sense to add such logic: would we
@@ -1910,17 +1878,17 @@ static struct diff_queue_struct *get_diffpairs(struct merge_options *o,
         */
        if (opts.detect_rename > DIFF_DETECT_RENAME)
                opts.detect_rename = DIFF_DETECT_RENAME;
-       opts.rename_limit = o->merge_rename_limit >= 0 ? o->merge_rename_limit :
-                           o->diff_rename_limit >= 0 ? o->diff_rename_limit :
+       opts.rename_limit = opt->merge_rename_limit >= 0 ? opt->merge_rename_limit :
+                           opt->diff_rename_limit >= 0 ? opt->diff_rename_limit :
                            1000;
-       opts.rename_score = o->rename_score;
-       opts.show_rename_progress = o->show_rename_progress;
+       opts.rename_score = opt->rename_score;
+       opts.show_rename_progress = opt->show_rename_progress;
        opts.output_format = DIFF_FORMAT_NO_OUTPUT;
        diff_setup_done(&opts);
        diff_tree_oid(&o_tree->object.oid, &tree->object.oid, "", &opts);
        diffcore_std(&opts);
-       if (opts.needed_rename_limit > o->needed_rename_limit)
-               o->needed_rename_limit = opts.needed_rename_limit;
+       if (opts.needed_rename_limit > opt->needed_rename_limit)
+               opt->needed_rename_limit = opts.needed_rename_limit;
 
        ret = xmalloc(sizeof(*ret));
        *ret = diff_queued_diff;
@@ -1935,7 +1903,7 @@ static struct diff_queue_struct *get_diffpairs(struct merge_options *o,
 static int tree_has_path(struct tree *tree, const char *path)
 {
        struct object_id hashy;
-       unsigned int mode_o;
+       unsigned short mode_o;
 
        return !get_tree_entry(&tree->object.oid, path,
                               &hashy, &mode_o);
@@ -2039,7 +2007,7 @@ static void remove_hashmap_entries(struct hashmap *dir_renames,
  * level conflicts for the renamed location.  If there is a rename and
  * there are no conflicts, return the new name.  Otherwise, return NULL.
  */
-static char *handle_path_level_conflicts(struct merge_options *o,
+static char *handle_path_level_conflicts(struct merge_options *opt,
                                         const char *path,
                                         struct dir_rename_entry *entry,
                                         struct hashmap *collisions,
@@ -2060,7 +2028,7 @@ static char *handle_path_level_conflicts(struct merge_options *o,
                /* This should only happen when entry->non_unique_new_dir set */
                if (!entry->non_unique_new_dir)
                        BUG("entry->non_unqiue_dir not set and !new_path");
-               output(o, 1, _("CONFLICT (directory rename split): "
+               output(opt, 1, _("CONFLICT (directory rename split): "
                               "Unclear where to place %s because directory "
                               "%s was renamed to multiple other directories, "
                               "with no destination getting a majority of the "
@@ -2092,7 +2060,7 @@ static char *handle_path_level_conflicts(struct merge_options *o,
                collision_ent->reported_already = 1;
                strbuf_add_separated_string_list(&collision_paths, ", ",
                                                 &collision_ent->source_files);
-               output(o, 1, _("CONFLICT (implicit dir rename): Existing "
+               output(opt, 1, _("CONFLICT (implicit dir rename): Existing "
                               "file/dir at %s in the way of implicit "
                               "directory rename(s) putting the following "
                               "path(s) there: %s."),
@@ -2102,7 +2070,7 @@ static char *handle_path_level_conflicts(struct merge_options *o,
                collision_ent->reported_already = 1;
                strbuf_add_separated_string_list(&collision_paths, ", ",
                                                 &collision_ent->source_files);
-               output(o, 1, _("CONFLICT (implicit dir rename): Cannot map "
+               output(opt, 1, _("CONFLICT (implicit dir rename): Cannot map "
                               "more than one path to %s; implicit directory "
                               "renames tried to put these paths there: %s"),
                       new_path, collision_paths.buf);
@@ -2139,7 +2107,7 @@ static char *handle_path_level_conflicts(struct merge_options *o,
  *         causes conflicts for files within those merged directories, then
  *         that should be detected at the individual path level.
  */
-static void handle_directory_level_conflicts(struct merge_options *o,
+static void handle_directory_level_conflicts(struct merge_options *opt,
                                             struct hashmap *dir_re_head,
                                             struct tree *head,
                                             struct hashmap *dir_re_merge,
@@ -2194,11 +2162,11 @@ static void handle_directory_level_conflicts(struct merge_options *o,
                         * know that head_ent->new_dir and merge_ent->new_dir
                         * are different strings.
                         */
-                       output(o, 1, _("CONFLICT (rename/rename): "
+                       output(opt, 1, _("CONFLICT (rename/rename): "
                                       "Rename directory %s->%s in %s. "
                                       "Rename directory %s->%s in %s"),
-                              head_ent->dir, head_ent->new_dir.buf, o->branch1,
-                              head_ent->dir, merge_ent->new_dir.buf, o->branch2);
+                              head_ent->dir, head_ent->new_dir.buf, opt->branch1,
+                              head_ent->dir, merge_ent->new_dir.buf, opt->branch2);
                        string_list_append(&remove_from_head,
                                           head_ent->dir)->util = head_ent;
                        strbuf_release(&head_ent->new_dir);
@@ -2397,7 +2365,7 @@ static void compute_collisions(struct hashmap *collisions,
        }
 }
 
-static char *check_for_directory_rename(struct merge_options *o,
+static char *check_for_directory_rename(struct merge_options *opt,
                                        const char *path,
                                        struct tree *tree,
                                        struct hashmap *dir_renames,
@@ -2438,11 +2406,11 @@ static char *check_for_directory_rename(struct merge_options *o,
         */
        oentry = dir_rename_find_entry(dir_rename_exclusions, entry->new_dir.buf);
        if (oentry) {
-               output(o, 1, _("WARNING: Avoiding applying %s -> %s rename "
+               output(opt, 1, _("WARNING: Avoiding applying %s -> %s rename "
                               "to %s, because %s itself was renamed."),
                       entry->dir, entry->new_dir.buf, path, entry->new_dir.buf);
        } else {
-               new_path = handle_path_level_conflicts(o, path, entry,
+               new_path = handle_path_level_conflicts(opt, path, entry,
                                                       collisions, tree);
                *clean_merge &= (new_path != NULL);
        }
@@ -2450,7 +2418,7 @@ static char *check_for_directory_rename(struct merge_options *o,
        return new_path;
 }
 
-static void apply_directory_rename_modifications(struct merge_options *o,
+static void apply_directory_rename_modifications(struct merge_options *opt,
                                                 struct diff_filepair *pair,
                                                 char *new_path,
                                                 struct rename *re,
@@ -2473,11 +2441,11 @@ static void apply_directory_rename_modifications(struct merge_options *o,
         * saying the file would have been overwritten), but it might
         * be dirty, though.
         */
-       update_wd = !was_dirty(o, pair->two->path);
+       update_wd = !was_dirty(opt, pair->two->path);
        if (!update_wd)
-               output(o, 1, _("Refusing to lose dirty file at %s"),
+               output(opt, 1, _("Refusing to lose dirty file at %s"),
                       pair->two->path);
-       remove_file(o, 1, pair->two->path, !update_wd);
+       remove_file(opt, 1, pair->two->path, !update_wd);
 
        /* Find or create a new re->dst_entry */
        item = string_list_lookup(entries, new_path);
@@ -2537,16 +2505,18 @@ static void apply_directory_rename_modifications(struct merge_options *o,
                       &re->dst_entry->stages[stage].oid,
                       &re->dst_entry->stages[stage].mode);
 
-       /* Update pair status */
-       if (pair->status == 'A') {
-               /*
-                * Recording rename information for this add makes it look
-                * like a rename/delete conflict.  Make sure we can
-                * correctly handle this as an add that was moved to a new
-                * directory instead of reporting a rename/delete conflict.
-                */
-               re->add_turned_into_rename = 1;
-       }
+       /*
+        * Record the original change status (or 'type' of change).  If it
+        * was originally an add ('A'), this lets us differentiate later
+        * between a RENAME_DELETE conflict and RENAME_VIA_DIR (they
+        * otherwise look the same).  If it was originally a rename ('R'),
+        * this lets us remember and report accurately about the transitive
+        * renaming that occurred via the directory rename detection.  Also,
+        * record the original destination name.
+        */
+       re->dir_rename_original_type = pair->status;
+       re->dir_rename_original_dest = pair->two->path;
+
        /*
         * We don't actually look at pair->status again, but it seems
         * pedagogically correct to adjust it.
@@ -2566,7 +2536,8 @@ static void apply_directory_rename_modifications(struct merge_options *o,
  * to be able to associate the correct cache entries with the rename
  * information; tree is always equal to either a_tree or b_tree.
  */
-static struct string_list *get_renames(struct merge_options *o,
+static struct string_list *get_renames(struct merge_options *opt,
+                                      const char *branch,
                                       struct diff_queue_struct *pairs,
                                       struct hashmap *dir_renames,
                                       struct hashmap *dir_rename_exclusions,
@@ -2596,7 +2567,7 @@ static struct string_list *get_renames(struct merge_options *o,
                        diff_free_filepair(pair);
                        continue;
                }
-               new_path = check_for_directory_rename(o, pair->two->path, tree,
+               new_path = check_for_directory_rename(opt, pair->two->path, tree,
                                                      dir_renames,
                                                      dir_rename_exclusions,
                                                      &collisions,
@@ -2608,8 +2579,10 @@ static struct string_list *get_renames(struct merge_options *o,
 
                re = xmalloc(sizeof(*re));
                re->processed = 0;
-               re->add_turned_into_rename = 0;
                re->pair = pair;
+               re->branch = branch;
+               re->dir_rename_original_type = '\0';
+               re->dir_rename_original_dest = NULL;
                item = string_list_lookup(entries, re->pair->one->path);
                if (!item)
                        re->src_entry = insert_stage_data(re->pair->one->path,
@@ -2626,7 +2599,7 @@ static struct string_list *get_renames(struct merge_options *o,
                item = string_list_insert(renames, pair->one->path);
                item->util = re;
                if (new_path)
-                       apply_directory_rename_modifications(o, pair, new_path,
+                       apply_directory_rename_modifications(opt, pair, new_path,
                                                             re, tree, o_tree,
                                                             a_tree, b_tree,
                                                             entries);
@@ -2641,7 +2614,7 @@ static struct string_list *get_renames(struct merge_options *o,
        return renames;
 }
 
-static int process_renames(struct merge_options *o,
+static int process_renames(struct merge_options *opt,
                           struct string_list *a_renames,
                           struct string_list *b_renames)
 {
@@ -2664,7 +2637,6 @@ static int process_renames(struct merge_options *o,
        for (i = 0, j = 0; i < a_renames->nr || j < b_renames->nr;) {
                struct string_list *renames1, *renames2Dst;
                struct rename *ren1 = NULL, *ren2 = NULL;
-               const char *branch1, *branch2;
                const char *ren1_src, *ren1_dst;
                struct string_list_item *lookup;
 
@@ -2685,13 +2657,9 @@ static int process_renames(struct merge_options *o,
                if (ren1) {
                        renames1 = a_renames;
                        renames2Dst = &b_by_dst;
-                       branch1 = o->branch1;
-                       branch2 = o->branch2;
                } else {
                        renames1 = b_renames;
                        renames2Dst = &a_by_dst;
-                       branch1 = o->branch2;
-                       branch2 = o->branch1;
                        SWAP(ren2, ren1);
                }
 
@@ -2725,22 +2693,13 @@ static int process_renames(struct merge_options *o,
                                 * the base stage (think of rename +
                                 * add-source cases).
                                 */
-                               remove_file(o, 1, ren1_src, 1);
+                               remove_file(opt, 1, ren1_src, 1);
                                update_entry(ren1->dst_entry,
                                             ren1->pair->one,
                                             ren1->pair->two,
                                             ren2->pair->two);
                        }
-                       setup_rename_conflict_info(rename_type,
-                                                  ren1->pair,
-                                                  ren2->pair,
-                                                  branch1,
-                                                  branch2,
-                                                  ren1->dst_entry,
-                                                  ren2->dst_entry,
-                                                  o,
-                                                  NULL,
-                                                  NULL);
+                       setup_rename_conflict_info(rename_type, opt, ren1, ren2);
                } else if ((lookup = string_list_lookup(renames2Dst, ren1_dst))) {
                        /* Two different files renamed to the same thing */
                        char *ren2_dst;
@@ -2759,16 +2718,7 @@ static int process_renames(struct merge_options *o,
                        ren2->src_entry->processed = 1;
 
                        setup_rename_conflict_info(RENAME_TWO_FILES_TO_ONE,
-                                                  ren1->pair,
-                                                  ren2->pair,
-                                                  branch1,
-                                                  branch2,
-                                                  ren1->dst_entry,
-                                                  ren2->dst_entry,
-                                                  o,
-                                                  ren1->src_entry,
-                                                  ren2->src_entry);
-
+                                                  opt, ren1, ren2);
                } else {
                        /* Renamed in 1, maybe changed in 2 */
                        /* we only use sha1 and mode of these */
@@ -2788,8 +2738,8 @@ static int process_renames(struct merge_options *o,
                         * stage and in other_stage (think of rename +
                         * add-source case).
                         */
-                       remove_file(o, 1, ren1_src,
-                                   renamed_stage == 2 || !was_tracked(o, ren1_src));
+                       remove_file(opt, 1, ren1_src,
+                                   renamed_stage == 2 || !was_tracked(opt, ren1_src));
 
                        oidcpy(&src_other.oid,
                               &ren1->src_entry->stages[other_stage].oid);
@@ -2800,28 +2750,12 @@ static int process_renames(struct merge_options *o,
                        try_merge = 0;
 
                        if (oid_eq(&src_other.oid, &null_oid) &&
-                           ren1->add_turned_into_rename) {
+                           ren1->dir_rename_original_type == 'A') {
                                setup_rename_conflict_info(RENAME_VIA_DIR,
-                                                          ren1->pair,
-                                                          NULL,
-                                                          branch1,
-                                                          branch2,
-                                                          ren1->dst_entry,
-                                                          NULL,
-                                                          o,
-                                                          NULL,
-                                                          NULL);
+                                                          opt, ren1, NULL);
                        } else if (oid_eq(&src_other.oid, &null_oid)) {
                                setup_rename_conflict_info(RENAME_DELETE,
-                                                          ren1->pair,
-                                                          NULL,
-                                                          branch1,
-                                                          branch2,
-                                                          ren1->dst_entry,
-                                                          NULL,
-                                                          o,
-                                                          NULL,
-                                                          NULL);
+                                                          opt, ren1, NULL);
                        } else if ((dst_other.mode == ren1->pair->two->mode) &&
                                   oid_eq(&dst_other.oid, &ren1->pair->two->oid)) {
                                /*
@@ -2832,9 +2766,8 @@ static int process_renames(struct merge_options *o,
                                 * update_file_flags() instead of
                                 * update_file().
                                 */
-                               if (update_file_flags(o,
-                                                     &ren1->pair->two->oid,
-                                                     ren1->pair->two->mode,
+                               if (update_file_flags(opt,
+                                                     ren1->pair->two,
                                                      ren1_dst,
                                                      1, /* update_cache */
                                                      0  /* update_wd    */))
@@ -2848,25 +2781,17 @@ static int process_renames(struct merge_options *o,
                                 * file, then the merge will be clean.
                                 */
                                setup_rename_conflict_info(RENAME_ADD,
-                                                          ren1->pair,
-                                                          NULL,
-                                                          branch1,
-                                                          branch2,
-                                                          ren1->dst_entry,
-                                                          NULL,
-                                                          o,
-                                                          ren1->src_entry,
-                                                          NULL);
+                                                          opt, ren1, NULL);
                        } else
                                try_merge = 1;
 
                        if (clean_merge < 0)
                                goto cleanup_and_return;
                        if (try_merge) {
-                               struct diff_filespec *one, *a, *b;
+                               struct diff_filespec *o, *a, *b;
                                src_other.path = (char *)ren1_src;
 
-                               one = ren1->pair->one;
+                               o = ren1->pair->one;
                                if (a_renames == renames1) {
                                        a = ren1->pair->two;
                                        b = &src_other;
@@ -2874,17 +2799,9 @@ static int process_renames(struct merge_options *o,
                                        b = ren1->pair->two;
                                        a = &src_other;
                                }
-                               update_entry(ren1->dst_entry, one, a, b);
+                               update_entry(ren1->dst_entry, o, a, b);
                                setup_rename_conflict_info(RENAME_NORMAL,
-                                                          ren1->pair,
-                                                          NULL,
-                                                          branch1,
-                                                          NULL,
-                                                          ren1->dst_entry,
-                                                          NULL,
-                                                          o,
-                                                          NULL,
-                                                          NULL);
+                                                          opt, ren1, NULL);
                        }
                }
        }
@@ -2919,7 +2836,7 @@ static void initial_cleanup_rename(struct diff_queue_struct *pairs,
        free(pairs);
 }
 
-static int detect_and_process_renames(struct merge_options *o,
+static int detect_and_process_renames(struct merge_options *opt,
                                      struct tree *common,
                                      struct tree *head,
                                      struct tree *merge,
@@ -2933,17 +2850,17 @@ static int detect_and_process_renames(struct merge_options *o,
        ri->head_renames = NULL;
        ri->merge_renames = NULL;
 
-       if (!merge_detect_rename(o))
+       if (!merge_detect_rename(opt))
                return 1;
 
-       head_pairs = get_diffpairs(o, common, head);
-       merge_pairs = get_diffpairs(o, common, merge);
+       head_pairs = get_diffpairs(opt, common, head);
+       merge_pairs = get_diffpairs(opt, common, merge);
 
-       if (o->detect_directory_renames) {
+       if (opt->detect_directory_renames) {
                dir_re_head = get_directory_renames(head_pairs);
                dir_re_merge = get_directory_renames(merge_pairs);
 
-               handle_directory_level_conflicts(o,
+               handle_directory_level_conflicts(opt,
                                                 dir_re_head, head,
                                                 dir_re_merge, merge);
        } else {
@@ -2953,19 +2870,19 @@ static int detect_and_process_renames(struct merge_options *o,
                dir_rename_init(dir_re_merge);
        }
 
-       ri->head_renames  = get_renames(o, head_pairs,
+       ri->head_renames  = get_renames(opt, opt->branch1, head_pairs,
                                        dir_re_merge, dir_re_head, head,
                                        common, head, merge, entries,
                                        &clean);
        if (clean < 0)
                goto cleanup;
-       ri->merge_renames = get_renames(o, merge_pairs,
+       ri->merge_renames = get_renames(opt, opt->branch2, merge_pairs,
                                        dir_re_head, dir_re_merge, merge,
                                        common, head, merge, entries,
                                        &clean);
        if (clean < 0)
                goto cleanup;
-       clean &= process_renames(o, ri->head_renames, ri->merge_renames);
+       clean &= process_renames(opt, ri->head_renames, ri->merge_renames);
 
 cleanup:
        /*
@@ -3001,12 +2918,7 @@ static void final_cleanup_renames(struct rename_info *re_info)
        final_cleanup_rename(re_info->merge_renames);
 }
 
-static struct object_id *stage_oid(const struct object_id *oid, unsigned mode)
-{
-       return (is_null_oid(oid) || mode == 0) ? NULL: (struct object_id *)oid;
-}
-
-static int read_oid_strbuf(struct merge_options *o,
+static int read_oid_strbuf(struct merge_options *opt,
                           const struct object_id *oid,
                           struct strbuf *dst)
 {
@@ -3015,130 +2927,99 @@ static int read_oid_strbuf(struct merge_options *o,
        unsigned long size;
        buf = read_object_file(oid, &type, &size);
        if (!buf)
-               return err(o, _("cannot read object %s"), oid_to_hex(oid));
+               return err(opt, _("cannot read object %s"), oid_to_hex(oid));
        if (type != OBJ_BLOB) {
                free(buf);
-               return err(o, _("object %s is not a blob"), oid_to_hex(oid));
+               return err(opt, _("object %s is not a blob"), oid_to_hex(oid));
        }
        strbuf_attach(dst, buf, size, size + 1);
        return 0;
 }
 
 static int blob_unchanged(struct merge_options *opt,
-                         const struct object_id *o_oid,
-                         unsigned o_mode,
-                         const struct object_id *a_oid,
-                         unsigned a_mode,
+                         const struct diff_filespec *o,
+                         const struct diff_filespec *a,
                          int renormalize, const char *path)
 {
-       struct strbuf o = STRBUF_INIT;
-       struct strbuf a = STRBUF_INIT;
+       struct strbuf obuf = STRBUF_INIT;
+       struct strbuf abuf = STRBUF_INIT;
        int ret = 0; /* assume changed for safety */
+       const struct index_state *idx = opt->repo->index;
 
-       if (a_mode != o_mode)
+       if (a->mode != o->mode)
                return 0;
-       if (oid_eq(o_oid, a_oid))
+       if (oid_eq(&o->oid, &a->oid))
                return 1;
        if (!renormalize)
                return 0;
 
-       assert(o_oid && a_oid);
-       if (read_oid_strbuf(opt, o_oid, &o) || read_oid_strbuf(opt, a_oid, &a))
+       if (read_oid_strbuf(opt, &o->oid, &obuf) ||
+           read_oid_strbuf(opt, &a->oid, &abuf))
                goto error_return;
        /*
         * Note: binary | is used so that both renormalizations are
         * performed.  Comparison can be skipped if both files are
         * unchanged since their sha1s have already been compared.
         */
-       if (renormalize_buffer(opt->repo->index, path, o.buf, o.len, &o) |
-           renormalize_buffer(opt->repo->index, path, a.buf, a.len, &a))
-               ret = (o.len == a.len && !memcmp(o.buf, a.buf, o.len));
+       if (renormalize_buffer(idx, path, obuf.buf, obuf.len, &obuf) |
+           renormalize_buffer(idx, path, abuf.buf, abuf.len, &abuf))
+               ret = (obuf.len == abuf.len && !memcmp(obuf.buf, abuf.buf, obuf.len));
 
 error_return:
-       strbuf_release(&o);
-       strbuf_release(&a);
+       strbuf_release(&obuf);
+       strbuf_release(&abuf);
        return ret;
 }
 
-static int handle_modify_delete(struct merge_options *o,
+static int handle_modify_delete(struct merge_options *opt,
                                const char *path,
-                               struct object_id *o_oid, int o_mode,
-                               struct object_id *a_oid, int a_mode,
-                               struct object_id *b_oid, int b_mode)
+                               const struct diff_filespec *o,
+                               const struct diff_filespec *a,
+                               const struct diff_filespec *b)
 {
        const char *modify_branch, *delete_branch;
-       struct object_id *changed_oid;
-       int changed_mode;
-
-       if (a_oid) {
-               modify_branch = o->branch1;
-               delete_branch = o->branch2;
-               changed_oid = a_oid;
-               changed_mode = a_mode;
+       const struct diff_filespec *changed;
+
+       if (is_valid(a)) {
+               modify_branch = opt->branch1;
+               delete_branch = opt->branch2;
+               changed = a;
        } else {
-               modify_branch = o->branch2;
-               delete_branch = o->branch1;
-               changed_oid = b_oid;
-               changed_mode = b_mode;
+               modify_branch = opt->branch2;
+               delete_branch = opt->branch1;
+               changed = b;
        }
 
-       return handle_change_delete(o,
+       return handle_change_delete(opt,
                                    path, NULL,
-                                   o_oid, o_mode,
-                                   changed_oid, changed_mode,
+                                   o, changed,
                                    modify_branch, delete_branch,
                                    _("modify"), _("modified"));
 }
 
-static int handle_content_merge(struct merge_options *o,
+static int handle_content_merge(struct merge_file_info *mfi,
+                               struct merge_options *opt,
                                const char *path,
                                int is_dirty,
-                               struct object_id *o_oid, int o_mode,
-                               struct object_id *a_oid, int a_mode,
-                               struct object_id *b_oid, int b_mode,
-                               struct rename_conflict_info *rename_conflict_info)
+                               const struct diff_filespec *o,
+                               const struct diff_filespec *a,
+                               const struct diff_filespec *b,
+                               struct rename_conflict_info *ci)
 {
        const char *reason = _("content");
-       const char *path1 = NULL, *path2 = NULL;
-       struct merge_file_info mfi;
-       struct diff_filespec one, a, b;
        unsigned df_conflict_remains = 0;
 
-       if (!o_oid) {
+       if (!is_valid(o))
                reason = _("add/add");
-               o_oid = (struct object_id *)&null_oid;
-       }
-       one.path = a.path = b.path = (char *)path;
-       oidcpy(&one.oid, o_oid);
-       one.mode = o_mode;
-       oidcpy(&a.oid, a_oid);
-       a.mode = a_mode;
-       oidcpy(&b.oid, b_oid);
-       b.mode = b_mode;
-
-       if (rename_conflict_info) {
-               struct diff_filepair *pair1 = rename_conflict_info->pair1;
-
-               path1 = (o->branch1 == rename_conflict_info->branch1) ?
-                       pair1->two->path : pair1->one->path;
-               /* If rename_conflict_info->pair2 != NULL, we are in
-                * RENAME_ONE_FILE_TO_ONE case.  Otherwise, we have a
-                * normal rename.
-                */
-               path2 = (rename_conflict_info->pair2 ||
-                        o->branch2 == rename_conflict_info->branch1) ?
-                       pair1->two->path : pair1->one->path;
-               one.path = pair1->one->path;
-               a.path = (char *)path1;
-               b.path = (char *)path2;
-
-               if (dir_in_way(o->repo->index, path, !o->call_depth,
-                              S_ISGITLINK(pair1->two->mode)))
-                       df_conflict_remains = 1;
-       }
-       if (merge_mode_and_contents(o, &one, &a, &b, path,
-                                   o->branch1, o->branch2,
-                                   o->call_depth * 2, &mfi))
+
+       assert(o->path && a->path && b->path);
+       if (ci && dir_in_way(opt->repo->index, path, !opt->call_depth,
+                            S_ISGITLINK(ci->ren1->pair->two->mode)))
+               df_conflict_remains = 1;
+
+       if (merge_mode_and_contents(opt, o, a, b, path,
+                                   opt->branch1, opt->branch2,
+                                   opt->call_depth * 2, mfi))
                return -1;
 
        /*
@@ -3147,15 +3028,14 @@ static int handle_content_merge(struct merge_options *o,
         *   b) The merge matches what was in HEAD (content, mode, pathname)
         *   c) The target path is usable (i.e. not involved in D/F conflict)
         */
-       if (mfi.clean &&
-           was_tracked_and_matches(o, path, &mfi.oid, mfi.mode) &&
+       if (mfi->clean && was_tracked_and_matches(opt, path, &mfi->blob) &&
            !df_conflict_remains) {
                int pos;
                struct cache_entry *ce;
 
-               output(o, 3, _("Skipped %s (merged same as existing)"), path);
-               if (add_cacheinfo(o, mfi.mode, &mfi.oid, path,
-                                 0, (!o->call_depth && !is_dirty), 0))
+               output(opt, 3, _("Skipped %s (merged same as existing)"), path);
+               if (add_cacheinfo(opt, &mfi->blob, path,
+                                 0, (!opt->call_depth && !is_dirty), 0))
                        return -1;
                /*
                 * However, add_cacheinfo() will delete the old cache entry
@@ -3163,109 +3043,196 @@ static int handle_content_merge(struct merge_options *o,
                 * flag to avoid making the file appear as if it were
                 * deleted by the user.
                 */
-               pos = index_name_pos(&o->orig_index, path, strlen(path));
-               ce = o->orig_index.cache[pos];
+               pos = index_name_pos(&opt->orig_index, path, strlen(path));
+               ce = opt->orig_index.cache[pos];
                if (ce_skip_worktree(ce)) {
-                       pos = index_name_pos(o->repo->index, path, strlen(path));
-                       ce = o->repo->index->cache[pos];
+                       pos = index_name_pos(opt->repo->index, path, strlen(path));
+                       ce = opt->repo->index->cache[pos];
                        ce->ce_flags |= CE_SKIP_WORKTREE;
                }
-               return mfi.clean;
+               return mfi->clean;
        }
 
-       if (!mfi.clean) {
-               if (S_ISGITLINK(mfi.mode))
+       if (!mfi->clean) {
+               if (S_ISGITLINK(mfi->blob.mode))
                        reason = _("submodule");
-               output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
+               output(opt, 1, _("CONFLICT (%s): Merge conflict in %s"),
                                reason, path);
-               if (rename_conflict_info && !df_conflict_remains)
-                       if (update_stages(o, path, &one, &a, &b))
+               if (ci && !df_conflict_remains)
+                       if (update_stages(opt, path, o, a, b))
                                return -1;
        }
 
        if (df_conflict_remains || is_dirty) {
                char *new_path;
-               if (o->call_depth) {
-                       remove_file_from_index(o->repo->index, path);
+               if (opt->call_depth) {
+                       remove_file_from_index(opt->repo->index, path);
                } else {
-                       if (!mfi.clean) {
-                               if (update_stages(o, path, &one, &a, &b))
+                       if (!mfi->clean) {
+                               if (update_stages(opt, path, o, a, b))
                                        return -1;
                        } else {
-                               int file_from_stage2 = was_tracked(o, path);
-                               struct diff_filespec merged;
-                               oidcpy(&merged.oid, &mfi.oid);
-                               merged.mode = mfi.mode;
-
-                               if (update_stages(o, path, NULL,
-                                                 file_from_stage2 ? &merged : NULL,
-                                                 file_from_stage2 ? NULL : &merged))
+                               int file_from_stage2 = was_tracked(opt, path);
+
+                               if (update_stages(opt, path, NULL,
+                                                 file_from_stage2 ? &mfi->blob : NULL,
+                                                 file_from_stage2 ? NULL : &mfi->blob))
                                        return -1;
                        }
 
                }
-               new_path = unique_path(o, path, rename_conflict_info->branch1);
+               new_path = unique_path(opt, path, ci->ren1->branch);
                if (is_dirty) {
-                       output(o, 1, _("Refusing to lose dirty file at %s"),
+                       output(opt, 1, _("Refusing to lose dirty file at %s"),
                               path);
                }
-               output(o, 1, _("Adding as %s instead"), new_path);
-               if (update_file(o, 0, &mfi.oid, mfi.mode, new_path)) {
+               output(opt, 1, _("Adding as %s instead"), new_path);
+               if (update_file(opt, 0, &mfi->blob, new_path)) {
                        free(new_path);
                        return -1;
                }
                free(new_path);
-               mfi.clean = 0;
-       } else if (update_file(o, mfi.clean, &mfi.oid, mfi.mode, path))
+               mfi->clean = 0;
+       } else if (update_file(opt, mfi->clean, &mfi->blob, path))
                return -1;
-       return !is_dirty && mfi.clean;
+       return !is_dirty && mfi->clean;
 }
 
-static int handle_rename_normal(struct merge_options *o,
+static int handle_rename_normal(struct merge_options *opt,
                                const char *path,
-                               struct object_id *o_oid, unsigned int o_mode,
-                               struct object_id *a_oid, unsigned int a_mode,
-                               struct object_id *b_oid, unsigned int b_mode,
+                               const struct diff_filespec *o,
+                               const struct diff_filespec *a,
+                               const struct diff_filespec *b,
                                struct rename_conflict_info *ci)
 {
+       struct rename *ren = ci->ren1;
+       struct merge_file_info mfi;
+       int clean;
+       int side = (ren->branch == opt->branch1 ? 2 : 3);
+
        /* Merge the content and write it out */
-       return handle_content_merge(o, path, was_dirty(o, path),
-                                   o_oid, o_mode, a_oid, a_mode, b_oid, b_mode,
-                                   ci);
+       clean = handle_content_merge(&mfi, opt, path, was_dirty(opt, path),
+                                    o, a, b, ci);
+
+       if (clean && opt->detect_directory_renames == 1 &&
+           ren->dir_rename_original_dest) {
+               if (update_stages(opt, path,
+                                 NULL,
+                                 side == 2 ? &mfi.blob : NULL,
+                                 side == 2 ? NULL : &mfi.blob))
+                       return -1;
+               clean = 0; /* not clean, but conflicted */
+       }
+       return clean;
+}
+
+static void dir_rename_warning(const char *msg,
+                              int is_add,
+                              int clean,
+                              struct merge_options *opt,
+                              struct rename *ren)
+{
+       const char *other_branch;
+       other_branch = (ren->branch == opt->branch1 ?
+                       opt->branch2 : opt->branch1);
+       if (is_add) {
+               output(opt, clean ? 2 : 1, msg,
+                      ren->pair->one->path, ren->branch,
+                      other_branch, ren->pair->two->path);
+               return;
+       }
+       output(opt, clean ? 2 : 1, msg,
+              ren->pair->one->path, ren->dir_rename_original_dest, ren->branch,
+              other_branch, ren->pair->two->path);
+}
+static int warn_about_dir_renamed_entries(struct merge_options *opt,
+                                         struct rename *ren)
+{
+       const char *msg;
+       int clean = 1, is_add;
+
+       if (!ren)
+               return clean;
+
+       /* Return early if ren was not affected/created by a directory rename */
+       if (!ren->dir_rename_original_dest)
+               return clean;
+
+       /* Sanity checks */
+       assert(opt->detect_directory_renames > 0);
+       assert(ren->dir_rename_original_type == 'A' ||
+              ren->dir_rename_original_type == 'R');
+
+       /* Check whether to treat directory renames as a conflict */
+       clean = (opt->detect_directory_renames == 2);
+
+       is_add = (ren->dir_rename_original_type == 'A');
+       if (ren->dir_rename_original_type == 'A' && clean) {
+               msg = _("Path updated: %s added in %s inside a "
+                       "directory that was renamed in %s; moving it to %s.");
+       } else if (ren->dir_rename_original_type == 'A' && !clean) {
+               msg = _("CONFLICT (file location): %s added in %s "
+                       "inside a directory that was renamed in %s, "
+                       "suggesting it should perhaps be moved to %s.");
+       } else if (ren->dir_rename_original_type == 'R' && clean) {
+               msg = _("Path updated: %s renamed to %s in %s, inside a "
+                       "directory that was renamed in %s; moving it to %s.");
+       } else if (ren->dir_rename_original_type == 'R' && !clean) {
+               msg = _("CONFLICT (file location): %s renamed to %s in %s, "
+                       "inside a directory that was renamed in %s, "
+                       "suggesting it should perhaps be moved to %s.");
+       } else {
+               BUG("Impossible dir_rename_original_type/clean combination");
+       }
+       dir_rename_warning(msg, is_add, clean, opt, ren);
+
+       return clean;
 }
 
 /* Per entry merge function */
-static int process_entry(struct merge_options *o,
+static int process_entry(struct merge_options *opt,
                         const char *path, struct stage_data *entry)
 {
        int clean_merge = 1;
-       int normalize = o->renormalize;
-       unsigned o_mode = entry->stages[1].mode;
-       unsigned a_mode = entry->stages[2].mode;
-       unsigned b_mode = entry->stages[3].mode;
-       struct object_id *o_oid = stage_oid(&entry->stages[1].oid, o_mode);
-       struct object_id *a_oid = stage_oid(&entry->stages[2].oid, a_mode);
-       struct object_id *b_oid = stage_oid(&entry->stages[3].oid, b_mode);
+       int normalize = opt->renormalize;
+
+       struct diff_filespec *o = &entry->stages[1];
+       struct diff_filespec *a = &entry->stages[2];
+       struct diff_filespec *b = &entry->stages[3];
+       int o_valid = is_valid(o);
+       int a_valid = is_valid(a);
+       int b_valid = is_valid(b);
+       o->path = a->path = b->path = (char*)path;
 
        entry->processed = 1;
        if (entry->rename_conflict_info) {
-               struct rename_conflict_info *conflict_info = entry->rename_conflict_info;
-               switch (conflict_info->rename_type) {
+               struct rename_conflict_info *ci = entry->rename_conflict_info;
+               struct diff_filespec *temp;
+               int path_clean;
+
+               path_clean = warn_about_dir_renamed_entries(opt, ci->ren1);
+               path_clean &= warn_about_dir_renamed_entries(opt, ci->ren2);
+
+               /*
+                * For cases with a single rename, {o,a,b}->path have all been
+                * set to the rename target path; we need to set two of these
+                * back to the rename source.
+                * For rename/rename conflicts, we'll manually fix paths below.
+                */
+               temp = (opt->branch1 == ci->ren1->branch) ? b : a;
+               o->path = temp->path = ci->ren1->pair->one->path;
+               if (ci->ren2) {
+                       assert(opt->branch1 == ci->ren1->branch);
+               }
+
+               switch (ci->rename_type) {
                case RENAME_NORMAL:
                case RENAME_ONE_FILE_TO_ONE:
-                       clean_merge = handle_rename_normal(o,
-                                                          path,
-                                                          o_oid, o_mode,
-                                                          a_oid, a_mode,
-                                                          b_oid, b_mode,
-                                                          conflict_info);
+                       clean_merge = handle_rename_normal(opt, path, o, a, b,
+                                                          ci);
                        break;
                case RENAME_VIA_DIR:
-                       clean_merge = 1;
-                       if (handle_rename_via_dir(o,
-                                                 conflict_info->pair1,
-                                                 conflict_info->branch1))
-                               clean_merge = -1;
+                       clean_merge = handle_rename_via_dir(opt, ci);
                        break;
                case RENAME_ADD:
                        /*
@@ -3274,165 +3241,172 @@ static int process_entry(struct merge_options *o,
                         * two-way merged cleanly with the added file, I
                         * guess it's a clean merge?
                         */
-                       clean_merge = handle_rename_add(o, conflict_info);
+                       clean_merge = handle_rename_add(opt, ci);
                        break;
                case RENAME_DELETE:
                        clean_merge = 0;
-                       if (handle_rename_delete(o,
-                                                conflict_info->pair1,
-                                                conflict_info->branch1,
-                                                conflict_info->branch2))
+                       if (handle_rename_delete(opt, ci))
                                clean_merge = -1;
                        break;
                case RENAME_ONE_FILE_TO_TWO:
+                       /*
+                        * Manually fix up paths; note:
+                        * ren[12]->pair->one->path are equal.
+                        */
+                       o->path = ci->ren1->pair->one->path;
+                       a->path = ci->ren1->pair->two->path;
+                       b->path = ci->ren2->pair->two->path;
+
                        clean_merge = 0;
-                       if (handle_rename_rename_1to2(o, conflict_info))
+                       if (handle_rename_rename_1to2(opt, ci))
                                clean_merge = -1;
                        break;
                case RENAME_TWO_FILES_TO_ONE:
+                       /*
+                        * Manually fix up paths; note,
+                        * ren[12]->pair->two->path are actually equal.
+                        */
+                       o->path = NULL;
+                       a->path = ci->ren1->pair->two->path;
+                       b->path = ci->ren2->pair->two->path;
+
                        /*
                         * Probably unclean merge, but if the two renamed
                         * files merge cleanly and the two resulting files
                         * can then be two-way merged cleanly, I guess it's
                         * a clean merge?
                         */
-                       clean_merge = handle_rename_rename_2to1(o,
-                                                               conflict_info);
+                       clean_merge = handle_rename_rename_2to1(opt, ci);
                        break;
                default:
                        entry->processed = 0;
                        break;
                }
-       } else if (o_oid && (!a_oid || !b_oid)) {
+               if (path_clean < clean_merge)
+                       clean_merge = path_clean;
+       } else if (o_valid && (!a_valid || !b_valid)) {
                /* Case A: Deleted in one */
-               if ((!a_oid && !b_oid) ||
-                   (!b_oid && blob_unchanged(o, o_oid, o_mode, a_oid, a_mode, normalize, path)) ||
-                   (!a_oid && blob_unchanged(o, o_oid, o_mode, b_oid, b_mode, normalize, path))) {
+               if ((!a_valid && !b_valid) ||
+                   (!b_valid && blob_unchanged(opt, o, a, normalize, path)) ||
+                   (!a_valid && blob_unchanged(opt, o, b, normalize, path))) {
                        /* Deleted in both or deleted in one and
                         * unchanged in the other */
-                       if (a_oid)
-                               output(o, 2, _("Removing %s"), path);
+                       if (a_valid)
+                               output(opt, 2, _("Removing %s"), path);
                        /* do not touch working file if it did not exist */
-                       remove_file(o, 1, path, !a_oid);
+                       remove_file(opt, 1, path, !a_valid);
                } else {
                        /* Modify/delete; deleted side may have put a directory in the way */
                        clean_merge = 0;
-                       if (handle_modify_delete(o, path, o_oid, o_mode,
-                                                a_oid, a_mode, b_oid, b_mode))
+                       if (handle_modify_delete(opt, path, o, a, b))
                                clean_merge = -1;
                }
-       } else if ((!o_oid && a_oid && !b_oid) ||
-                  (!o_oid && !a_oid && b_oid)) {
+       } else if ((!o_valid && a_valid && !b_valid) ||
+                  (!o_valid && !a_valid && b_valid)) {
                /* Case B: Added in one. */
                /* [nothing|directory] -> ([nothing|directory], file) */
 
                const char *add_branch;
                const char *other_branch;
-               unsigned mode;
-               const struct object_id *oid;
                const char *conf;
+               const struct diff_filespec *contents;
 
-               if (a_oid) {
-                       add_branch = o->branch1;
-                       other_branch = o->branch2;
-                       mode = a_mode;
-                       oid = a_oid;
+               if (a_valid) {
+                       add_branch = opt->branch1;
+                       other_branch = opt->branch2;
+                       contents = a;
                        conf = _("file/directory");
                } else {
-                       add_branch = o->branch2;
-                       other_branch = o->branch1;
-                       mode = b_mode;
-                       oid = b_oid;
+                       add_branch = opt->branch2;
+                       other_branch = opt->branch1;
+                       contents = b;
                        conf = _("directory/file");
                }
-               if (dir_in_way(o->repo->index, path,
-                              !o->call_depth && !S_ISGITLINK(a_mode),
+               if (dir_in_way(opt->repo->index, path,
+                              !opt->call_depth && !S_ISGITLINK(a->mode),
                               0)) {
-                       char *new_path = unique_path(o, path, add_branch);
+                       char *new_path = unique_path(opt, path, add_branch);
                        clean_merge = 0;
-                       output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
+                       output(opt, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
                               "Adding %s as %s"),
                               conf, path, other_branch, path, new_path);
-                       if (update_file(o, 0, oid, mode, new_path))
+                       if (update_file(opt, 0, contents, new_path))
                                clean_merge = -1;
-                       else if (o->call_depth)
-                               remove_file_from_index(o->repo->index, path);
+                       else if (opt->call_depth)
+                               remove_file_from_index(opt->repo->index, path);
                        free(new_path);
                } else {
-                       output(o, 2, _("Adding %s"), path);
+                       output(opt, 2, _("Adding %s"), path);
                        /* do not overwrite file if already present */
-                       if (update_file_flags(o, oid, mode, path, 1, !a_oid))
+                       if (update_file_flags(opt, contents, path, 1, !a_valid))
                                clean_merge = -1;
                }
-       } else if (a_oid && b_oid) {
-               if (!o_oid) {
+       } else if (a_valid && b_valid) {
+               if (!o_valid) {
                        /* Case C: Added in both (check for same permissions) */
-                       output(o, 1,
+                       output(opt, 1,
                               _("CONFLICT (add/add): Merge conflict in %s"),
                               path);
-                       clean_merge = handle_file_collision(o,
+                       clean_merge = handle_file_collision(opt,
                                                            path, NULL, NULL,
-                                                           o->branch1,
-                                                           o->branch2,
-                                                           a_oid, a_mode,
-                                                           b_oid, b_mode);
+                                                           opt->branch1,
+                                                           opt->branch2,
+                                                           a, b);
                } else {
                        /* case D: Modified in both, but differently. */
+                       struct merge_file_info mfi;
                        int is_dirty = 0; /* unpack_trees would have bailed if dirty */
-                       clean_merge = handle_content_merge(o, path,
+                       clean_merge = handle_content_merge(&mfi, opt, path,
                                                           is_dirty,
-                                                          o_oid, o_mode,
-                                                          a_oid, a_mode,
-                                                          b_oid, b_mode,
-                                                          NULL);
+                                                          o, a, b, NULL);
                }
-       } else if (!o_oid && !a_oid && !b_oid) {
+       } else if (!o_valid && !a_valid && !b_valid) {
                /*
                 * this entry was deleted altogether. a_mode == 0 means
                 * we had that path and want to actively remove it.
                 */
-               remove_file(o, 1, path, !a_mode);
+               remove_file(opt, 1, path, !a->mode);
        } else
                BUG("fatal merge failure, shouldn't happen.");
 
        return clean_merge;
 }
 
-int merge_trees(struct merge_options *o,
+int merge_trees(struct merge_options *opt,
                struct tree *head,
                struct tree *merge,
                struct tree *common,
                struct tree **result)
 {
-       struct index_state *istate = o->repo->index;
+       struct index_state *istate = opt->repo->index;
        int code, clean;
        struct strbuf sb = STRBUF_INIT;
 
-       if (!o->call_depth && repo_index_has_changes(o->repo, head, &sb)) {
-               err(o, _("Your local changes to the following files would be overwritten by merge:\n  %s"),
+       if (!opt->call_depth && repo_index_has_changes(opt->repo, head, &sb)) {
+               err(opt, _("Your local changes to the following files would be overwritten by merge:\n  %s"),
                    sb.buf);
                return -1;
        }
 
-       if (o->subtree_shift) {
-               merge = shift_tree_object(o->repo, head, merge, o->subtree_shift);
-               common = shift_tree_object(o->repo, head, common, o->subtree_shift);
+       if (opt->subtree_shift) {
+               merge = shift_tree_object(opt->repo, head, merge, opt->subtree_shift);
+               common = shift_tree_object(opt->repo, head, common, opt->subtree_shift);
        }
 
        if (oid_eq(&common->object.oid, &merge->object.oid)) {
-               output(o, 0, _("Already up to date!"));
+               output(opt, 0, _("Already up to date!"));
                *result = head;
                return 1;
        }
 
-       code = unpack_trees_start(o, common, head, merge);
+       code = unpack_trees_start(opt, common, head, merge);
 
        if (code != 0) {
-               if (show(o, 4) || o->call_depth)
-                       err(o, _("merging of trees %s and %s failed"),
+               if (show(opt, 4) || opt->call_depth)
+                       err(opt, _("merging of trees %s and %s failed"),
                            oid_to_hex(&head->object.oid),
                            oid_to_hex(&merge->object.oid));
-               unpack_trees_finish(o);
+               unpack_trees_finish(opt);
                return -1;
        }
 
@@ -3447,21 +3421,21 @@ int merge_trees(struct merge_options *o,
                 * opposed to decaring a local hashmap is for convenience
                 * so that we don't have to pass it to around.
                 */
-               hashmap_init(&o->current_file_dir_set, path_hashmap_cmp, NULL, 512);
-               get_files_dirs(o, head);
-               get_files_dirs(o, merge);
+               hashmap_init(&opt->current_file_dir_set, path_hashmap_cmp, NULL, 512);
+               get_files_dirs(opt, head);
+               get_files_dirs(opt, merge);
 
-               entries = get_unmerged(o->repo->index);
-               clean = detect_and_process_renames(o, common, head, merge,
+               entries = get_unmerged(opt->repo->index);
+               clean = detect_and_process_renames(opt, common, head, merge,
                                                   entries, &re_info);
-               record_df_conflict_files(o, entries);
+               record_df_conflict_files(opt, entries);
                if (clean < 0)
                        goto cleanup;
                for (i = entries->nr-1; 0 <= i; i--) {
                        const char *path = entries->items[i].string;
                        struct stage_data *e = entries->items[i].util;
                        if (!e->processed) {
-                               int ret = process_entry(o, path, e);
+                               int ret = process_entry(opt, path, e);
                                if (!ret)
                                        clean = 0;
                                else if (ret < 0) {
@@ -3483,19 +3457,19 @@ int merge_trees(struct merge_options *o,
                string_list_clear(entries, 1);
                free(entries);
 
-               hashmap_free(&o->current_file_dir_set, 1);
+               hashmap_free(&opt->current_file_dir_set, 1);
 
                if (clean < 0) {
-                       unpack_trees_finish(o);
+                       unpack_trees_finish(opt);
                        return clean;
                }
        }
        else
                clean = 1;
 
-       unpack_trees_finish(o);
+       unpack_trees_finish(opt);
 
-       if (o->call_depth && !(*result = write_tree_from_memory(o)))
+       if (opt->call_depth && !(*result = write_tree_from_memory(opt)))
                return -1;
 
        return clean;
@@ -3516,7 +3490,7 @@ static struct commit_list *reverse_commit_list(struct commit_list *list)
  * Merge the commits h1 and h2, return the resulting virtual
  * commit object and a flag indicating the cleanness of the merge.
  */
-int merge_recursive(struct merge_options *o,
+int merge_recursive(struct merge_options *opt,
                    struct commit *h1,
                    struct commit *h2,
                    struct commit_list *ca,
@@ -3527,10 +3501,10 @@ int merge_recursive(struct merge_options *o,
        struct tree *mrtree;
        int clean;
 
-       if (show(o, 4)) {
-               output(o, 4, _("Merging:"));
-               output_commit_title(o, h1);
-               output_commit_title(o, h2);
+       if (show(opt, 4)) {
+               output(opt, 4, _("Merging:"));
+               output_commit_title(opt, h1);
+               output_commit_title(opt, h2);
        }
 
        if (!ca) {
@@ -3538,13 +3512,13 @@ int merge_recursive(struct merge_options *o,
                ca = reverse_commit_list(ca);
        }
 
-       if (show(o, 5)) {
+       if (show(opt, 5)) {
                unsigned cnt = commit_list_count(ca);
 
-               output(o, 5, Q_("found %u common ancestor:",
+               output(opt, 5, Q_("found %u common ancestor:",
                                "found %u common ancestors:", cnt), cnt);
                for (iter = ca; iter; iter = iter->next)
-                       output_commit_title(o, iter->item);
+                       output_commit_title(opt, iter->item);
        }
 
        merged_common_ancestors = pop_commit(&ca);
@@ -3552,13 +3526,13 @@ int merge_recursive(struct merge_options *o,
                /* if there is no common ancestor, use an empty tree */
                struct tree *tree;
 
-               tree = lookup_tree(o->repo, o->repo->hash_algo->empty_tree);
-               merged_common_ancestors = make_virtual_commit(o->repo, tree, "ancestor");
+               tree = lookup_tree(opt->repo, opt->repo->hash_algo->empty_tree);
+               merged_common_ancestors = make_virtual_commit(opt->repo, tree, "ancestor");
        }
 
        for (iter = ca; iter; iter = iter->next) {
                const char *saved_b1, *saved_b2;
-               o->call_depth++;
+               opt->call_depth++;
                /*
                 * When the merge fails, the result contains files
                 * with conflict markers. The cleanness flag is
@@ -3567,46 +3541,46 @@ int merge_recursive(struct merge_options *o,
                 * overwritten it: the committed "conflicts" were
                 * already resolved.
                 */
-               discard_index(o->repo->index);
-               saved_b1 = o->branch1;
-               saved_b2 = o->branch2;
-               o->branch1 = "Temporary merge branch 1";
-               o->branch2 = "Temporary merge branch 2";
-               if (merge_recursive(o, merged_common_ancestors, iter->item,
+               discard_index(opt->repo->index);
+               saved_b1 = opt->branch1;
+               saved_b2 = opt->branch2;
+               opt->branch1 = "Temporary merge branch 1";
+               opt->branch2 = "Temporary merge branch 2";
+               if (merge_recursive(opt, merged_common_ancestors, iter->item,
                                    NULL, &merged_common_ancestors) < 0)
                        return -1;
-               o->branch1 = saved_b1;
-               o->branch2 = saved_b2;
-               o->call_depth--;
+               opt->branch1 = saved_b1;
+               opt->branch2 = saved_b2;
+               opt->call_depth--;
 
                if (!merged_common_ancestors)
-                       return err(o, _("merge returned no commit"));
+                       return err(opt, _("merge returned no commit"));
        }
 
-       discard_index(o->repo->index);
-       if (!o->call_depth)
-               repo_read_index(o->repo);
+       discard_index(opt->repo->index);
+       if (!opt->call_depth)
+               repo_read_index(opt->repo);
 
-       o->ancestor = "merged common ancestors";
-       clean = merge_trees(o, get_commit_tree(h1), get_commit_tree(h2),
+       opt->ancestor = "merged common ancestors";
+       clean = merge_trees(opt, get_commit_tree(h1), get_commit_tree(h2),
                            get_commit_tree(merged_common_ancestors),
                            &mrtree);
        if (clean < 0) {
-               flush_output(o);
+               flush_output(opt);
                return clean;
        }
 
-       if (o->call_depth) {
-               *result = make_virtual_commit(o->repo, mrtree, "merged tree");
+       if (opt->call_depth) {
+               *result = make_virtual_commit(opt->repo, mrtree, "merged tree");
                commit_list_insert(h1, &(*result)->parents);
                commit_list_insert(h2, &(*result)->parents->next);
        }
-       flush_output(o);
-       if (!o->call_depth && o->buffer_output < 2)
-               strbuf_release(&o->obuf);
-       if (show(o, 2))
+       flush_output(opt);
+       if (!opt->call_depth && opt->buffer_output < 2)
+               strbuf_release(&opt->obuf);
+       if (show(opt, 2))
                diff_warn_rename_limit("merge.renamelimit",
-                                      o->needed_rename_limit, 0);
+                                      opt->needed_rename_limit, 0);
        return clean;
 }
 
@@ -3628,7 +3602,7 @@ static struct commit *get_ref(struct repository *repo, const struct object_id *o
        return (struct commit *)object;
 }
 
-int merge_recursive_generic(struct merge_options *o,
+int merge_recursive_generic(struct merge_options *opt,
                            const struct object_id *head,
                            const struct object_id *merge,
                            int num_base_list,
@@ -3637,127 +3611,136 @@ int merge_recursive_generic(struct merge_options *o,
 {
        int clean;
        struct lock_file lock = LOCK_INIT;
-       struct commit *head_commit = get_ref(o->repo, head, o->branch1);
-       struct commit *next_commit = get_ref(o->repo, merge, o->branch2);
+       struct commit *head_commit = get_ref(opt->repo, head, opt->branch1);
+       struct commit *next_commit = get_ref(opt->repo, merge, opt->branch2);
        struct commit_list *ca = NULL;
 
        if (base_list) {
                int i;
                for (i = 0; i < num_base_list; ++i) {
                        struct commit *base;
-                       if (!(base = get_ref(o->repo, base_list[i], oid_to_hex(base_list[i]))))
-                               return err(o, _("Could not parse object '%s'"),
+                       if (!(base = get_ref(opt->repo, base_list[i], oid_to_hex(base_list[i]))))
+                               return err(opt, _("Could not parse object '%s'"),
                                           oid_to_hex(base_list[i]));
                        commit_list_insert(base, &ca);
                }
        }
 
-       repo_hold_locked_index(o->repo, &lock, LOCK_DIE_ON_ERROR);
-       clean = merge_recursive(o, head_commit, next_commit, ca,
+       repo_hold_locked_index(opt->repo, &lock, LOCK_DIE_ON_ERROR);
+       clean = merge_recursive(opt, head_commit, next_commit, ca,
                                result);
        if (clean < 0) {
                rollback_lock_file(&lock);
                return clean;
        }
 
-       if (write_locked_index(o->repo->index, &lock,
+       if (write_locked_index(opt->repo->index, &lock,
                               COMMIT_LOCK | SKIP_IF_UNCHANGED))
-               return err(o, _("Unable to write index."));
+               return err(opt, _("Unable to write index."));
 
        return clean ? 0 : 1;
 }
 
-static void merge_recursive_config(struct merge_options *o)
+static void merge_recursive_config(struct merge_options *opt)
 {
        char *value = NULL;
-       git_config_get_int("merge.verbosity", &o->verbosity);
-       git_config_get_int("diff.renamelimit", &o->diff_rename_limit);
-       git_config_get_int("merge.renamelimit", &o->merge_rename_limit);
+       git_config_get_int("merge.verbosity", &opt->verbosity);
+       git_config_get_int("diff.renamelimit", &opt->diff_rename_limit);
+       git_config_get_int("merge.renamelimit", &opt->merge_rename_limit);
        if (!git_config_get_string("diff.renames", &value)) {
-               o->diff_detect_rename = git_config_rename("diff.renames", value);
+               opt->diff_detect_rename = git_config_rename("diff.renames", value);
                free(value);
        }
        if (!git_config_get_string("merge.renames", &value)) {
-               o->merge_detect_rename = git_config_rename("merge.renames", value);
+               opt->merge_detect_rename = git_config_rename("merge.renames", value);
+               free(value);
+       }
+       if (!git_config_get_string("merge.directoryrenames", &value)) {
+               int boolval = git_parse_maybe_bool(value);
+               if (0 <= boolval) {
+                       opt->detect_directory_renames = boolval ? 2 : 0;
+               } else if (!strcasecmp(value, "conflict")) {
+                       opt->detect_directory_renames = 1;
+               } /* avoid erroring on values from future versions of git */
                free(value);
        }
        git_config(git_xmerge_config, NULL);
 }
 
-void init_merge_options(struct merge_options *o,
+void init_merge_options(struct merge_options *opt,
                        struct repository *repo)
 {
        const char *merge_verbosity;
-       memset(o, 0, sizeof(struct merge_options));
-       o->repo = repo;
-       o->verbosity = 2;
-       o->buffer_output = 1;
-       o->diff_rename_limit = -1;
-       o->merge_rename_limit = -1;
-       o->renormalize = 0;
-       o->diff_detect_rename = -1;
-       o->merge_detect_rename = -1;
-       o->detect_directory_renames = 1;
-       merge_recursive_config(o);
+       memset(opt, 0, sizeof(struct merge_options));
+       opt->repo = repo;
+       opt->verbosity = 2;
+       opt->buffer_output = 1;
+       opt->diff_rename_limit = -1;
+       opt->merge_rename_limit = -1;
+       opt->renormalize = 0;
+       opt->diff_detect_rename = -1;
+       opt->merge_detect_rename = -1;
+       opt->detect_directory_renames = 1;
+       merge_recursive_config(opt);
        merge_verbosity = getenv("GIT_MERGE_VERBOSITY");
        if (merge_verbosity)
-               o->verbosity = strtol(merge_verbosity, NULL, 10);
-       if (o->verbosity >= 5)
-               o->buffer_output = 0;
-       strbuf_init(&o->obuf, 0);
-       string_list_init(&o->df_conflict_file_set, 1);
+               opt->verbosity = strtol(merge_verbosity, NULL, 10);
+       if (opt->verbosity >= 5)
+               opt->buffer_output = 0;
+       strbuf_init(&opt->obuf, 0);
+       string_list_init(&opt->df_conflict_file_set, 1);
 }
 
-int parse_merge_opt(struct merge_options *o, const char *s)
+int parse_merge_opt(struct merge_options *opt, const char *s)
 {
        const char *arg;
 
        if (!s || !*s)
                return -1;
        if (!strcmp(s, "ours"))
-               o->recursive_variant = MERGE_RECURSIVE_OURS;
+               opt->recursive_variant = MERGE_RECURSIVE_OURS;
        else if (!strcmp(s, "theirs"))
-               o->recursive_variant = MERGE_RECURSIVE_THEIRS;
+               opt->recursive_variant = MERGE_RECURSIVE_THEIRS;
        else if (!strcmp(s, "subtree"))
-               o->subtree_shift = "";
+               opt->subtree_shift = "";
        else if (skip_prefix(s, "subtree=", &arg))
-               o->subtree_shift = arg;
+               opt->subtree_shift = arg;
        else if (!strcmp(s, "patience"))
-               o->xdl_opts = DIFF_WITH_ALG(o, PATIENCE_DIFF);
+               opt->xdl_opts = DIFF_WITH_ALG(opt, PATIENCE_DIFF);
        else if (!strcmp(s, "histogram"))
-               o->xdl_opts = DIFF_WITH_ALG(o, HISTOGRAM_DIFF);
+               opt->xdl_opts = DIFF_WITH_ALG(opt, HISTOGRAM_DIFF);
        else if (skip_prefix(s, "diff-algorithm=", &arg)) {
                long value = parse_algorithm_value(arg);
                if (value < 0)
                        return -1;
                /* clear out previous settings */
-               DIFF_XDL_CLR(o, NEED_MINIMAL);
-               o->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
-               o->xdl_opts |= value;
+               DIFF_XDL_CLR(opt, NEED_MINIMAL);
+               opt->xdl_opts &= ~XDF_DIFF_ALGORITHM_MASK;
+               opt->xdl_opts |= value;
        }
        else if (!strcmp(s, "ignore-space-change"))
-               DIFF_XDL_SET(o, IGNORE_WHITESPACE_CHANGE);
+               DIFF_XDL_SET(opt, IGNORE_WHITESPACE_CHANGE);
        else if (!strcmp(s, "ignore-all-space"))
-               DIFF_XDL_SET(o, IGNORE_WHITESPACE);
+               DIFF_XDL_SET(opt, IGNORE_WHITESPACE);
        else if (!strcmp(s, "ignore-space-at-eol"))
-               DIFF_XDL_SET(o, IGNORE_WHITESPACE_AT_EOL);
+               DIFF_XDL_SET(opt, IGNORE_WHITESPACE_AT_EOL);
        else if (!strcmp(s, "ignore-cr-at-eol"))
-               DIFF_XDL_SET(o, IGNORE_CR_AT_EOL);
+               DIFF_XDL_SET(opt, IGNORE_CR_AT_EOL);
        else if (!strcmp(s, "renormalize"))
-               o->renormalize = 1;
+               opt->renormalize = 1;
        else if (!strcmp(s, "no-renormalize"))
-               o->renormalize = 0;
+               opt->renormalize = 0;
        else if (!strcmp(s, "no-renames"))
-               o->merge_detect_rename = 0;
+               opt->merge_detect_rename = 0;
        else if (!strcmp(s, "find-renames")) {
-               o->merge_detect_rename = 1;
-               o->rename_score = 0;
+               opt->merge_detect_rename = 1;
+               opt->rename_score = 0;
        }
        else if (skip_prefix(s, "find-renames=", &arg) ||
                 skip_prefix(s, "rename-threshold=", &arg)) {
-               if ((o->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
+               if ((opt->rename_score = parse_rename_score(&arg)) == -1 || *arg != 0)
                        return -1;
-               o->merge_detect_rename = 1;
+               opt->merge_detect_rename = 1;
        }
        /*
         * Please update $__git_merge_strategy_options in