log --remerge-diff

index 8400a8e..c36dc79 100644
@@ -545,11 +545,9 @@ static int update_stages(const char *path, const struct diff_filespec *o,
 	 * would_lose_untracked).  Instead, reverse the order of the calls
 	 * (executing update_file first and then update_stages).
 	 */
-	int clear = 1;
 	int options = ADD_CACHE_OK_TO_ADD | ADD_CACHE_SKIP_DFCHECK;
-	if (clear)
-		if (remove_file_from_cache(path))
-			return -1;
+	if (remove_file_from_cache(path))
+		return -1;
 	if (o)
 		if (add_cacheinfo(o->mode, o->sha1, path, 1, 0, options))
 			return -1;

index c36dc79..35be144 100644
@@ -408,10 +408,10 @@ static void record_df_conflict_files(struct merge_options *o,
 	int i;
 
 	/*
-	 * If we're merging merge-bases, we don't want to bother with
-	 * any working directory changes.
+	 * If we're working in-core only (e.g., merging merge-bases),
+	 * we don't want to bother with any working directory changes.
 	 */
-	if (o->call_depth)
+	if (o->call_depth || o->no_worktree)
 		return;
 
 	/* Ensure D/F conflicts are adjacent in the entries list. */

@@ -724,7 +724,7 @@ static void update_file_flags(struct merge_options *o,
 			      int update_cache,
 			      int update_wd)
 {
-	if (o->call_depth)
+	if (o->call_depth || o->no_worktree)
 		update_wd = 0;
 
 	if (update_wd) {

@@ -931,7 +931,8 @@ static struct merge_file_info merge_file_1(struct merge_options *o,
 			result.clean = merge_submodule(result.sha,
 						       one->path, one->sha1,
 						       a->sha1, b->sha1,
-						       !o->call_depth);
+						       !(o->call_depth ||
+							 o->no_worktree));
 		} else if (S_ISLNK(a->mode)) {
 			hashcpy(result.sha, a->sha1);
 

@@ -1003,7 +1004,7 @@ static void handle_change_delete(struct merge_options *o,
 				 const char *change, const char *change_past)
 {
 	char *renamed = NULL;
-	if (dir_in_way(path, !o->call_depth)) {
+	if (dir_in_way(path, !(o->call_depth || o->no_worktree))) {
 		renamed = unique_path(o, path, a_sha ? o->branch1 : o->branch2);
 	}
 

@@ -1128,10 +1129,10 @@ static void handle_file(struct merge_options *o,
 		char *add_name = unique_path(o, rename->path, other_branch);
 		update_file(o, 0, add->sha1, add->mode, add_name);
 
-		remove_file(o, 0, rename->path, 0);
+		remove_file(o, 0, rename->path, o->call_depth || o->no_worktree);
 		dst_name = unique_path(o, rename->path, cur_branch);
 	} else {
-		if (dir_in_way(rename->path, !o->call_depth)) {
+		if (dir_in_way(rename->path, !(o->call_depth || o->no_worktree))) {
 			dst_name = unique_path(o, rename->path, cur_branch);
 			output(o, 1, _("%s is a directory in %s adding as %s instead"),
 			       rename->path, other_branch, dst_name);

@@ -1238,7 +1239,7 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 		 * merge base just undo the renames; they can be detected
 		 * again later for the non-recursive merge.
 		 */
-		remove_file(o, 0, path, 0);
+		remove_file(o, 0, path, o->call_depth || o->no_worktree);
 		update_file(o, 0, mfi_c1.sha, mfi_c1.mode, a->path);
 		update_file(o, 0, mfi_c2.sha, mfi_c2.mode, b->path);
 	} else {

@@ -1246,7 +1247,7 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 		char *new_path2 = unique_path(o, path, ci->branch2);
 		output(o, 1, _("Renaming %s to %s and %s to %s instead"),
 		       a->path, new_path1, b->path, new_path2);
-		remove_file(o, 0, path, 0);
+		remove_file(o, 0, path, o->call_depth || o->no_worktree);
 		update_file(o, 0, mfi_c1.sha, mfi_c1.mode, new_path1);
 		update_file(o, 0, mfi_c2.sha, mfi_c2.mode, new_path2);
 		free(new_path2);

@@ -1405,6 +1406,7 @@ static int process_renames(struct merge_options *o,
 			 * add-source case).
 			 */
 			remove_file(o, 1, ren1_src,
+				    o->call_depth || o->no_worktree ||
 				    renamed_stage == 2 || !was_tracked(ren1_src));
 
 			hashcpy(src_other.sha1, ren1->src_entry->stages[other_stage].sha);

@@ -1601,7 +1603,7 @@ static int merge_content(struct merge_options *o,
 			 o->branch2 == rename_conflict_info->branch1) ?
 			pair1->two->path : pair1->one->path;
 
-		if (dir_in_way(path, !o->call_depth))
+		if (dir_in_way(path, !(o->call_depth || o->no_worktree)))
 			df_conflict_remains = 1;
 	}
 	mfi = merge_file_special_markers(o, &one, &a, &b,

@@ -1621,7 +1623,7 @@ static int merge_content(struct merge_options *o,
 		path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
 		if (!path_renamed_outside_HEAD) {
 			add_cacheinfo(mfi.mode, mfi.sha, path,
-				      0, (!o->call_depth), 0);
+				      0, !(o->call_depth || o->no_worktree), 0);
 			return mfi.clean;
 		}
 	} else

@@ -1722,7 +1724,8 @@ static int process_entry(struct merge_options *o,
 			if (a_sha)
 				output(o, 2, _("Removing %s"), path);
 			/* do not touch working file if it did not exist */
-			remove_file(o, 1, path, !a_sha);
+			remove_file(o, 1, path,
+				    o->call_depth || o->no_worktree || !a_sha);
 		} else {
 			/* Modify/delete; deleted side may have put a directory in the way */
 			clean_merge = 0;

@@ -1753,7 +1756,7 @@ static int process_entry(struct merge_options *o,
 			sha = b_sha;
 			conf = _("directory/file");
 		}
-		if (dir_in_way(path, !o->call_depth)) {
+		if (dir_in_way(path, !(o->call_depth || o->no_worktree))) {
 			char *new_path = unique_path(o, path, add_branch);
 			clean_merge = 0;
 			output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "

@@ -1781,7 +1784,8 @@ static int process_entry(struct merge_options *o,
 		 * 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(o, 1, path,
+			    o->call_depth || o->no_worktree || !a_mode);
 	} else
 		die(_("Fatal merge failure, shouldn't happen."));
 

@@ -1807,7 +1811,8 @@ int merge_trees(struct merge_options *o,
 		return 1;
 	}
 
-	code = git_merge_trees(o->call_depth, common, head, merge);
+	code = git_merge_trees(o->call_depth || o->no_worktree,
+			       common, head, merge);
 
 	if (code != 0) {
 		if (show(o, 4) || o->call_depth)

index 9e090a3..d8dd7a1 100644
@@ -15,6 +15,7 @@ struct merge_options {
 	const char *subtree_shift;
 	unsigned buffer_output : 1;
 	unsigned renormalize : 1;
+	unsigned no_worktree : 1; /* do not touch worktree */
 	long xdl_opts;
 	int verbosity;
 	int diff_rename_limit;

index 35be144..f59c1d3 100644
@@ -2096,6 +2096,8 @@ int parse_merge_opt(struct merge_options *o, const char *s)
 		if ((o->rename_score = parse_rename_score(&score)) == -1 || *score != 0)
 			return -1;
 	}
+	else if (!strcmp(s, "index-only"))
+		o->no_worktree = 1;
 	else
 		return -1;
 	return 0;

index 0f247d2..47f663b 100644
@@ -196,8 +196,7 @@ static int builtin_diff_combined(struct rev_info *revs,
 		revs->dense_combined_merges = revs->combine_merges = 1;
 	for (i = 1; i < ents; i++)
 		sha1_array_append(&parents, ent[i].item->sha1);
-	diff_tree_combined(ent[0].item->sha1, &parents,
-			   revs->dense_combined_merges, revs);
+	diff_tree_combined(ent[0].item->sha1, &parents, revs);
 	sha1_array_clear(&parents);
 	return 0;
 }

index 3b92c448..6e80a73 100644
@@ -952,7 +952,7 @@ static void show_combined_header(struct combine_diff_path *elem,
 }
 
 static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
-			    int dense, int working_tree_file,
+			    int working_tree_file,
 			    struct rev_info *rev)
 {
 	struct diff_options *opt = &rev->diffopt;

@@ -967,6 +967,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	struct userdiff_driver *textconv = NULL;
 	int is_binary;
 	const char *line_prefix = diff_line_prefix(opt);
+	int dense = rev->dense_combined_merges;
 
 	context = opt->context;
 	userdiff = userdiff_find_by_path(elem->path);

@@ -1214,7 +1215,6 @@ static void show_raw_diff(struct combine_diff_path *p, int num_parent, struct re
  */
 void show_combined_diff(struct combine_diff_path *p,
 		       int num_parent,
-		       int dense,
 		       struct rev_info *rev)
 {
 	struct diff_options *opt = &rev->diffopt;

@@ -1226,7 +1226,7 @@ void show_combined_diff(struct combine_diff_path *p,
 				  DIFF_FORMAT_NAME_STATUS))
 		show_raw_diff(p, num_parent, rev);
 	else if (opt->output_format & DIFF_FORMAT_PATCH)
-		show_patch_diff(p, num_parent, dense, 1, rev);
+		show_patch_diff(p, num_parent, 1, rev);
 }
 
 static void free_combined_pair(struct diff_filepair *pair)

@@ -1297,7 +1297,6 @@ static void handle_combined_callback(struct diff_options *opt,
 
 void diff_tree_combined(const unsigned char *sha1,
 			const struct sha1_array *parents,
-			int dense,
 			struct rev_info *rev)
 {
 	struct diff_options *opt = &rev->diffopt;

@@ -1365,7 +1364,7 @@ void diff_tree_combined(const unsigned char *sha1,
 				       opt->line_termination);
 			for (p = paths; p; p = p->next) {
 				if (p->len)
-					show_patch_diff(p, num_parent, dense,
+					show_patch_diff(p, num_parent,
 							0, rev);
 			}
 		}

@@ -1381,7 +1380,7 @@ void diff_tree_combined(const unsigned char *sha1,
 	free_pathspec(&diffopts.pathspec);
 }
 
-void diff_tree_combined_merge(const struct commit *commit, int dense,
+void diff_tree_combined_merge(const struct commit *commit,
 			      struct rev_info *rev)
 {
 	struct commit_list *parent = get_saved_parents(rev, commit);

@@ -1391,6 +1390,6 @@ void diff_tree_combined_merge(const struct commit *commit, int dense,
 		sha1_array_append(&parents, parent->item->object.sha1);
 		parent = parent->next;
 	}
-	diff_tree_combined(commit->object.sha1, &parents, dense, rev);
+	diff_tree_combined(commit->object.sha1, &parents, rev);
 	sha1_array_clear(&parents);
 }

index 346cac6..8d0f572 100644
@@ -174,9 +174,7 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			i--;
 
 			if (revs->combine_merges && num_compare_stages == 2) {
-				show_combined_diff(dpath, 2,
-						   revs->dense_combined_merges,
-						   revs);
+				show_combined_diff(dpath, 2, revs);
 				free(dpath);
 				continue;
 			}

@@ -338,7 +336,7 @@ static int show_modified(struct rev_info *revs,
 		p->parent[1].status = DIFF_STATUS_MODIFIED;
 		p->parent[1].mode = old->ce_mode;
 		hashcpy(p->parent[1].sha1, old->sha1);
-		show_combined_diff(p, 2, revs->dense_combined_merges, revs);
+		show_combined_diff(p, 2, revs);
 		free(p);
 		return 0;
 	}

index ce123fa..ff77802 100644
@@ -213,11 +213,11 @@ struct combine_diff_path {
 	 sizeof(struct combine_diff_parent) * (n) + (l) + 1)
 
 extern void show_combined_diff(struct combine_diff_path *elem, int num_parent,
-			      int dense, struct rev_info *);
+			       struct rev_info *);
 
-extern void diff_tree_combined(const unsigned char *sha1, const struct sha1_array *parents, int dense, struct rev_info *rev);
+extern void diff_tree_combined(const unsigned char *sha1, const struct sha1_array *parents, struct rev_info *rev);
 
-extern void diff_tree_combined_merge(const struct commit *commit, int dense, struct rev_info *rev);
+extern void diff_tree_combined_merge(const struct commit *commit, struct rev_info *rev);
 
 void diff_set_mnemonic_prefix(struct diff_options *options, const char *a, const char *b);
 

index 08970bf..4c04812 100644
@@ -718,7 +718,7 @@ int log_tree_diff_flush(struct rev_info *opt)
 
 static int do_diff_combined(struct rev_info *opt, struct commit *commit)
 {
-	diff_tree_combined_merge(commit, opt->dense_combined_merges, opt);
+	diff_tree_combined_merge(commit, opt);
 	return !opt->loginfo;
 }
 

index 613857e..83b80fb 100644
@@ -505,10 +505,13 @@ static void find_unpushed_submodule_commits(struct commit *commit,
 	struct rev_info rev;
 
 	init_revisions(&rev, NULL);
+	rev.ignore_merges = 0;
+	rev.combined_merges = 1;
+	rev.dense_combined_merges = 1;
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = collect_submodules_from_diff;
 	rev.diffopt.format_callback_data = needs_pushing;
-	diff_tree_combined_merge(commit, 1, &rev);
+	diff_tree_combined_merge(commit, &rev);
 }
 
 int find_unpushed_submodules(unsigned char new_sha1[20],

index 9200069..172b50d 100644
@@ -57,9 +57,10 @@ int cmd_diff_files(int argc, const char **argv, const char *prefix)
 	 * was not asked to.  "diff-files -c -p" should not densify
 	 * (the user should ask with "diff-files --cc" explicitly).
 	 */
-	if (rev.max_count == -1 && !rev.combine_merges &&
+	if (rev.max_count == -1 &&
+	    !merge_diff_mode_is_any_combined(&rev) &&
 	    (rev.diffopt.output_format & DIFF_FORMAT_PATCH))
-		rev.combine_merges = rev.dense_combined_merges = 1;
+		rev.merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
 
 	if (read_cache_preload(&rev.diffopt.pathspec) < 0) {
 		perror("read_cache_preload");

index be6417d..2950f80 100644
@@ -96,7 +96,7 @@ static int diff_tree_stdin(char *line)
 static void diff_tree_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 {
 	if (!rev->diffopt.output_format) {
-		if (rev->dense_combined_merges)
+		if (rev->merge_diff_mode == MERGE_DIFF_COMBINED_CONDENSED)
 			rev->diffopt.output_format = DIFF_FORMAT_PATCH;
 		else
 			rev->diffopt.output_format = DIFF_FORMAT_RAW;

index 47f663b..fd4c75f 100644
@@ -192,8 +192,8 @@ static int builtin_diff_combined(struct rev_info *revs,
 	if (argc > 1)
 		usage(builtin_diff_usage);
 
-	if (!revs->dense_combined_merges && !revs->combine_merges)
-		revs->dense_combined_merges = revs->combine_merges = 1;
+	if (!merge_diff_mode_is_any_combined(revs))
+		revs->merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
 	for (i = 1; i < ents; i++)
 		sha1_array_append(&parents, ent[i].item->sha1);
 	diff_tree_combined(ent[0].item->sha1, &parents, revs);

@@ -242,9 +242,10 @@ static int builtin_diff_files(struct rev_info *revs, int argc, const char **argv
 	 * dense one, --cc can be explicitly asked for, or just rely
 	 * on the default).
 	 */
-	if (revs->max_count == -1 && !revs->combine_merges &&
+	if (revs->max_count == -1 &&
+	    !merge_diff_mode_is_any_combined(revs) &&
 	    (revs->diffopt.output_format & DIFF_FORMAT_PATCH))
-		revs->combine_merges = revs->dense_combined_merges = 1;
+		revs->merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
 
 	setup_work_tree();
 	if (read_cache_preload(&revs->diffopt.pathspec) < 0) {

index 3906eda..2deeacd 100644
@@ -637,7 +637,7 @@ int fmt_merge_msg(struct strbuf *in, struct strbuf *out,
 		head = lookup_commit_or_die(head_sha1, "HEAD");
 		init_revisions(&rev, NULL);
 		rev.commit_format = CMIT_FMT_ONELINE;
-		rev.ignore_merges = 1;
+		rev.merge_diff_mode = MERGE_DIFF_IGNORE;
 		rev.limited = 1;
 
 		strbuf_complete_line(out);

index b97373d..cebebea 100644
@@ -499,13 +499,12 @@ static int show_tree_object(const unsigned char *sha1,
 
 static void show_rev_tweak_rev(struct rev_info *rev, struct setup_revision_opt *opt)
 {
-	if (rev->ignore_merges) {
+	if (!rev->merge_diff_mode) {
 		/* There was no "-m" on the command line */
-		rev->ignore_merges = 0;
-		if (!rev->first_parent_only && !rev->combine_merges) {
+		rev->merge_diff_mode = MERGE_DIFF_EACH;
+		if (!rev->first_parent_only) {
 			/* No "--first-parent", "-c", nor "--cc" */
-			rev->combine_merges = 1;
-			rev->dense_combined_merges = 1;
+			rev->merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
 		}
 	}
 	if (!rev->diffopt.output_format)

index e576a7f..6977af7 100644
@@ -343,7 +343,6 @@ static void squash_message(struct commit *commit, struct commit_list *remotehead
 		die_errno(_("Could not write to '%s'"), filename);
 
 	init_revisions(&rev, NULL);
-	rev.ignore_merges = 1;
 	rev.commit_format = CMIT_FMT_MEDIUM;
 
 	commit->object.flags |= UNINTERESTING;

index 6e80a73..3fae2dd 100644
@@ -967,7 +967,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 	struct userdiff_driver *textconv = NULL;
 	int is_binary;
 	const char *line_prefix = diff_line_prefix(opt);
-	int dense = rev->dense_combined_merges;
+	int dense = (rev->merge_diff_mode == MERGE_DIFF_COMBINED_CONDENSED);
 
 	context = opt->context;
 	userdiff = userdiff_find_by_path(elem->path);

index 8d0f572..e2700eb 100644
@@ -173,7 +173,8 @@ int run_diff_files(struct rev_info *revs, unsigned int option)
 			 */
 			i--;
 
-			if (revs->combine_merges && num_compare_stages == 2) {
+			if (merge_diff_mode_is_any_combined(revs) &&
+			    num_compare_stages == 2) {
 				show_combined_diff(dpath, 2, revs);
 				free(dpath);
 				continue;

@@ -316,7 +317,7 @@ static int show_modified(struct rev_info *revs,
 		return -1;
 	}
 
-	if (revs->combine_merges && !cached &&
+	if (merge_diff_mode_is_any_combined(revs) && !cached &&
 	    (hashcmp(sha1, old->sha1) || hashcmp(old->sha1, new->sha1))) {
 		struct combine_diff_path *p;
 		int pathlen = ce_namelen(new);

@@ -375,7 +376,7 @@ static void do_oneway_diff(struct unpack_trees_options *o,
 	 * But with the revision flag parsing, that's found in
 	 * "!revs->ignore_merges".
 	 */
-	match_missing = !revs->ignore_merges;
+	match_missing = (revs->merge_diff_mode == MERGE_DIFF_EACH);
 
 	if (cached && idx && ce_stage(idx)) {
 		struct diff_filepair *pair;

index 4c04812..30b3063 100644
@@ -751,9 +751,9 @@ static int log_tree_diff(struct rev_info *opt, struct commit *commit, struct log
 
 	/* More than one parent? */
 	if (parents && parents->next) {
-		if (opt->ignore_merges)
+		if (opt->merge_diff_mode == MERGE_DIFF_IGNORE)
 			return 0;
-		else if (opt->combine_merges)
+		else if (merge_diff_mode_is_any_combined(opt))
 			return do_diff_combined(opt, commit);
 		else if (opt->first_parent_only) {
 			/*

index a0df72f..127b75a 100644
@@ -1329,7 +1329,6 @@ void init_revisions(struct rev_info *revs, const char *prefix)
 	memset(revs, 0, sizeof(*revs));
 
 	revs->abbrev = DEFAULT_ABBREV;
-	revs->ignore_merges = 1;
 	revs->simplify_history = 1;
 	DIFF_OPT_SET(&revs->pruning, RECURSIVE);
 	DIFF_OPT_SET(&revs->pruning, QUICK);

@@ -1807,15 +1806,11 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		DIFF_OPT_SET(&revs->diffopt, RECURSIVE);
 		DIFF_OPT_SET(&revs->diffopt, TREE_IN_RECURSIVE);
 	} else if (!strcmp(arg, "-m")) {
-		revs->ignore_merges = 0;
+		revs->merge_diff_mode = MERGE_DIFF_EACH;
 	} else if (!strcmp(arg, "-c")) {
-		revs->diff = 1;
-		revs->dense_combined_merges = 0;
-		revs->combine_merges = 1;
+		revs->merge_diff_mode = MERGE_DIFF_COMBINED;
 	} else if (!strcmp(arg, "--cc")) {
-		revs->diff = 1;
-		revs->dense_combined_merges = 1;
-		revs->combine_merges = 1;
+		revs->merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
 	} else if (!strcmp(arg, "-v")) {
 		revs->verbose_header = 1;
 	} else if (!strcmp(arg, "--pretty")) {

@@ -2228,8 +2223,6 @@ int setup_revisions(int argc, const char **argv, struct rev_info *revs, struct s
 			copy_pathspec(&revs->diffopt.pathspec,
 				      &revs->prune_data);
 	}
-	if (revs->combine_merges)
-		revs->ignore_merges = 0;
 	revs->diffopt.abbrev = revs->abbrev;
 
 	if (revs->line_level_traverse) {

index 88967d6..0847902 100644
@@ -50,6 +50,17 @@ struct rev_cmdline_info {
 #define REVISION_WALK_NO_WALK_SORTED 1
 #define REVISION_WALK_NO_WALK_UNSORTED 2
 
+enum merge_diff_mode {
+	/* default: do not show diffs for merge */
+	MERGE_DIFF_IGNORE = 0,
+	/* diff against each side (-m) */
+	MERGE_DIFF_EACH,
+	/* combined format (-c) */
+	MERGE_DIFF_COMBINED,
+	/* combined-condensed format (-cc) */
+	MERGE_DIFF_COMBINED_CONDENSED
+};
+
 struct rev_info {
 	/* Starting list */
 	struct commit_list *commits;

@@ -116,11 +127,10 @@ struct rev_info {
 			show_root_diff:1,
 			no_commit_id:1,
 			verbose_header:1,
-			ignore_merges:1,
-			combine_merges:1,
-			dense_combined_merges:1,
 			always_show_header:1;
 
+	enum merge_diff_mode merge_diff_mode;
+
 	/* Format info */
 	unsigned int	shown_one:1,
 			shown_dashes:1,

@@ -197,6 +207,12 @@ struct rev_info {
 	struct saved_parents *saved_parents_slab;
 };
 
+static inline int merge_diff_mode_is_any_combined(struct rev_info *revs)
+{
+	return (revs->merge_diff_mode == MERGE_DIFF_COMBINED ||
+		revs->merge_diff_mode == MERGE_DIFF_COMBINED_CONDENSED);
+}
+
 extern int ref_excluded(struct string_list *, const char *path);
 void clear_ref_exclusion(struct string_list **);
 void add_ref_exclusion(struct string_list **, const char *exclude);

index 83b80fb..38973f2 100644
@@ -505,9 +505,7 @@ static void find_unpushed_submodule_commits(struct commit *commit,
 	struct rev_info rev;
 
 	init_revisions(&rev, NULL);
-	rev.ignore_merges = 0;
-	rev.combined_merges = 1;
-	rev.dense_combined_merges = 1;
+	rev.merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
 	rev.diffopt.output_format |= DIFF_FORMAT_CALLBACK;
 	rev.diffopt.format_callback = collect_submodules_from_diff;
 	rev.diffopt.format_callback_data = needs_pushing;

index f59c1d3..b682812 100644
@@ -724,6 +724,8 @@ static void update_file_flags(struct merge_options *o,
 			      int update_cache,
 			      int update_wd)
 {
+	if (o->conflicts_in_index)
+		update_cache = 1;
 	if (o->call_depth || o->no_worktree)
 		update_wd = 0;
 

@@ -2098,6 +2100,8 @@ int parse_merge_opt(struct merge_options *o, const char *s)
 	}
 	else if (!strcmp(s, "index-only"))
 		o->no_worktree = 1;
+	else if (!strcmp(s, "conflicts-in-index"))
+		o->conflicts_in_index = 1;
 	else
 		return -1;
 	return 0;

index d8dd7a1..9b8e20b 100644
@@ -16,6 +16,7 @@ struct merge_options {
 	unsigned buffer_output : 1;
 	unsigned renormalize : 1;
 	unsigned no_worktree : 1; /* do not touch worktree */
+	unsigned conflicts_in_index : 1; /* index will contain conflict hunks */
 	long xdl_opts;
 	int verbosity;
 	int diff_rename_limit;

index dc040fb..e162021 100644
@@ -276,6 +276,7 @@ struct index_state {
 	struct cache_tree *cache_tree;
 	struct cache_time timestamp;
 	unsigned name_hash_initialized : 1,
+		 has_dir_hash : 1,
 		 initialized : 1;
 	struct hash_table name_hash;
 	struct hash_table dir_hash;

@@ -284,6 +285,7 @@ struct index_state {
 extern struct index_state the_index;
 
 /* Name hashing */
+extern void init_name_hash(struct index_state *istate, int force_dir_hash);
 extern void add_name_hash(struct index_state *istate, struct cache_entry *ce);
 extern void remove_name_hash(struct index_state *istate, struct cache_entry *ce);
 extern void free_name_hash(struct index_state *istate);

index e5b6e1a..c8953be 100644
@@ -141,16 +141,19 @@ static void hash_index_entry(struct index_state *istate, struct cache_entry *ce)
 		*pos = ce;
 	}
 
-	if (ignore_case && !(ce->ce_flags & CE_UNHASHED))
+	if (istate->has_dir_hash && !(ce->ce_flags & CE_UNHASHED))
 		add_dir_entry(istate, ce);
 }
 
-static void lazy_init_name_hash(struct index_state *istate)
+void init_name_hash(struct index_state *istate, int force_dir_hash)
 {
 	int nr;
 
 	if (istate->name_hash_initialized)
 		return;
+
+	istate->has_dir_hash = force_dir_hash || ignore_case;
+
 	if (istate->cache_nr)
 		preallocate_hash(&istate->name_hash, istate->cache_nr);
 	for (nr = 0; nr < istate->cache_nr; nr++)

@@ -161,7 +164,7 @@ static void lazy_init_name_hash(struct index_state *istate)
 void add_name_hash(struct index_state *istate, struct cache_entry *ce)
 {
 	/* if already hashed, add reference to directory entries */
-	if (ignore_case && (ce->ce_flags & CE_STATE_MASK) == CE_STATE_MASK)
+	if (istate->has_dir_hash && (ce->ce_flags & CE_STATE_MASK) == CE_STATE_MASK)
 		add_dir_entry(istate, ce);
 
 	ce->ce_flags &= ~CE_UNHASHED;

@@ -181,7 +184,7 @@ void add_name_hash(struct index_state *istate, struct cache_entry *ce)
 void remove_name_hash(struct index_state *istate, struct cache_entry *ce)
 {
 	/* if already hashed, release reference to directory entries */
-	if (ignore_case && (ce->ce_flags & CE_STATE_MASK) == CE_HASHED)
+	if (istate->has_dir_hash && (ce->ce_flags & CE_STATE_MASK) == CE_HASHED)
 		remove_dir_entry(istate, ce);
 
 	ce->ce_flags |= CE_UNHASHED;

@@ -228,7 +231,7 @@ struct cache_entry *index_dir_exists(struct index_state *istate, const char *nam
 	struct cache_entry *ce;
 	struct dir_entry *dir;
 
-	lazy_init_name_hash(istate);
+	init_name_hash(istate, 0);
 	dir = find_dir_entry(istate, name, namelen);
 	if (dir && dir->nr)
 		return dir->ce;

@@ -250,7 +253,7 @@ struct cache_entry *index_file_exists(struct index_state *istate, const char *na
 	unsigned int hash = hash_name(name, namelen);
 	struct cache_entry *ce;
 
-	lazy_init_name_hash(istate);
+	init_name_hash(istate, 0);
 	ce = lookup_hash(hash, &istate->name_hash);
 
 	while (ce) {

@@ -286,9 +289,11 @@ void free_name_hash(struct index_state *istate)
 	if (!istate->name_hash_initialized)
 		return;
 	istate->name_hash_initialized = 0;
-	if (ignore_case)
+	if (istate->has_dir_hash) {
 		/* free directory entries */
 		for_each_hash(&istate->dir_hash, free_dir_entry, NULL);
+		istate->has_dir_hash = 0;
+	}
 
 	free_hash(&istate->name_hash);
 	free_hash(&istate->dir_hash);

316 lines not on this page · raw message

index b682812..1507a7a 100644
@@ -1947,7 +1947,7 @@ int merge_recursive(struct merge_options *o,
 	}
 
 	discard_cache();
-	if (!o->call_depth)
+	if (!o->call_depth && o->use_ondisk_index)
 		read_cache();
 
 	o->ancestor = "merged common ancestors";

@@ -2043,6 +2043,7 @@ void init_merge_options(struct merge_options *o)
 	o->diff_rename_limit = -1;
 	o->merge_rename_limit = -1;
 	o->renormalize = 0;
+	o->use_ondisk_index = 1;
 	git_config(merge_recursive_config, o);
 	if (getenv("GIT_MERGE_VERBOSITY"))
 		o->verbosity =

index 9b8e20b..d7466c7 100644
@@ -17,6 +17,7 @@ struct merge_options {
 	unsigned renormalize : 1;
 	unsigned no_worktree : 1; /* do not touch worktree */
 	unsigned conflicts_in_index : 1; /* index will contain conflict hunks */
+	unsigned use_ondisk_index : 1; /* tree-level merge loads .git/index */
 	long xdl_opts;
 	int verbosity;
 	int diff_rename_limit;

index 127b75a..956a527 100644
@@ -1811,6 +1811,8 @@ static int handle_revision_opt(struct rev_info *revs, int argc, const char **arg
 		revs->merge_diff_mode = MERGE_DIFF_COMBINED;
 	} else if (!strcmp(arg, "--cc")) {
 		revs->merge_diff_mode = MERGE_DIFF_COMBINED_CONDENSED;
+	} else if (!strcmp(arg, "--remerge-diff")) {
+		revs->merge_diff_mode = MERGE_DIFF_REMERGE;
 	} else if (!strcmp(arg, "-v")) {
 		revs->verbose_header = 1;
 	} else if (!strcmp(arg, "--pretty")) {

index 0847902..10a2992 100644
@@ -58,7 +58,9 @@ enum merge_diff_mode {
 	/* combined format (-c) */
 	MERGE_DIFF_COMBINED,
 	/* combined-condensed format (-cc) */
-	MERGE_DIFF_COMBINED_CONDENSED
+	MERGE_DIFF_COMBINED_CONDENSED,
+	/* --remerge-diff */
+	MERGE_DIFF_REMERGE
 };
 
 struct rev_info {