diff --git a/merge-recursive.c b/merge-recursive.c
index 1f86338ad3..6beb1e4916 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -742,12 +742,12 @@ static int make_room_for_path(struct merge_options *o, const char *path)
 	return error(msg, path, _(": perhaps a D/F conflict?"));
 }
 
-static void update_file_flags(struct merge_options *o,
-			      const struct object_id *oid,
-			      unsigned mode,
-			      const char *path,
-			      int update_cache,
-			      int update_wd)
+static int update_file_flags(struct merge_options *o,
+			     const struct object_id *oid,
+			     unsigned mode,
+			     const char *path,
+			     int update_cache,
+			     int update_wd)
 {
 	if (o->call_depth)
 		update_wd = 0;
@@ -783,8 +783,7 @@ static void update_file_flags(struct merge_options *o,
 
 		if (make_room_for_path(o, path) < 0) {
 			update_wd = 0;
-			free(buf);
-			goto update_index;
+			goto free_buf;
 		}
 		if (S_ISREG(mode) || (!has_symlinks && S_ISLNK(mode))) {
 			int fd;
@@ -807,20 +806,22 @@ static void update_file_flags(struct merge_options *o,
 		} else
 			die(_("do not know what to do with %06o %s '%s'"),
 			    mode, oid_to_hex(oid), path);
+ free_buf:
 		free(buf);
 	}
  update_index:
 	if (update_cache)
 		add_cacheinfo(mode, oid, path, 0, update_wd, ADD_CACHE_OK_TO_ADD);
+	return 0;
 }
 
-static void update_file(struct merge_options *o,
-			int clean,
-			const struct object_id *oid,
-			unsigned mode,
-			const char *path)
+static int update_file(struct merge_options *o,
+		       int clean,
+		       const struct object_id *oid,
+		       unsigned mode,
+		       const char *path)
 {
-	update_file_flags(o, oid, mode, path, o->call_depth || clean, !o->call_depth);
+	return update_file_flags(o, oid, mode, path, o->call_depth || clean, !o->call_depth);
 }
 
 /* Low level file merging, update and removal */
@@ -1019,7 +1020,7 @@ static int merge_file_one(struct merge_options *o,
 	return merge_file_1(o, &one, &a, &b, branch1, branch2, mfi);
 }
 
-static void handle_change_delete(struct merge_options *o,
+static int handle_change_delete(struct merge_options *o,
 				 const char *path,
 				 const struct object_id *o_oid, int o_mode,
 				 const struct object_id *a_oid, int a_mode,
@@ -1027,6 +1028,7 @@ static void handle_change_delete(struct merge_options *o,
 				 const char *change, const char *change_past)
 {
 	char *renamed = NULL;
+	int ret = 0;
 	if (dir_in_way(path, !o->call_depth)) {
 		renamed = unique_path(o, path, a_oid ? o->branch1 : o->branch2);
 	}
@@ -1037,21 +1039,23 @@ static void handle_change_delete(struct merge_options *o,
 		 * correct; since there is no true "middle point" between
 		 * them, simply reuse the base version for virtual merge base.
 		 */
-		remove_file_from_cache(path);
-		update_file(o, 0, o_oid, o_mode, renamed ? renamed : path);
+		ret = remove_file_from_cache(path);
+		if (!ret)
+			ret = update_file(o, 0, o_oid, o_mode,
+					  renamed ? renamed : path);
 	} else if (!a_oid) {
 		if (!renamed) {
 			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
 			       "and %s in %s. Version %s of %s left in tree."),
 			       change, path, o->branch1, change_past,
 			       o->branch2, o->branch2, path);
-			update_file(o, 0, b_oid, b_mode, path);
+			ret = update_file(o, 0, b_oid, b_mode, path);
 		} else {
 			output(o, 1, _("CONFLICT (%s/delete): %s deleted in %s "
 			       "and %s in %s. Version %s of %s left in tree at %s."),
 			       change, path, o->branch1, change_past,
 			       o->branch2, o->branch2, path, renamed);
-			update_file(o, 0, b_oid, b_mode, renamed);
+			ret = update_file(o, 0, b_oid, b_mode, renamed);
 		}
 	} else {
 		if (!renamed) {
@@ -1064,7 +1068,7 @@ static void handle_change_delete(struct merge_options *o,
 			       "and %s in %s. Version %s of %s left in tree at %s."),
 			       change, path, o->branch2, change_past,
 			       o->branch1, o->branch1, path, renamed);
-			update_file(o, 0, a_oid, a_mode, renamed);
+			ret = update_file(o, 0, a_oid, a_mode, renamed);
 		}
 		/*
 		 * No need to call update_file() on path when !renamed, since
@@ -1074,9 +1078,11 @@ static void handle_change_delete(struct merge_options *o,
 		 */
 	}
 	free(renamed);
+
+	return ret;
 }
 
-static void conflict_rename_delete(struct merge_options *o,
+static int conflict_rename_delete(struct merge_options *o,
 				   struct diff_filepair *pair,
 				   const char *rename_branch,
 				   const char *other_branch)
@@ -1096,21 +1102,20 @@ static void conflict_rename_delete(struct merge_options *o,
 		b_mode = dest->mode;
 	}
 
-	handle_change_delete(o,
-			     o->call_depth ? orig->path : dest->path,
-			     &orig->oid, orig->mode,
-			     a_oid, a_mode,
-			     b_oid, b_mode,
-			     _("rename"), _("renamed"));
-
-	if (o->call_depth) {
-		remove_file_from_cache(dest->path);
-	} else {
-		update_stages(dest->path, NULL,
-			      rename_branch == o->branch1 ? dest : NULL,
-			      rename_branch == o->branch1 ? NULL : dest);
-	}
+	if (handle_change_delete(o,
+				 o->call_depth ? orig->path : dest->path,
+				 &orig->oid, orig->mode,
+				 a_oid, a_mode,
+				 b_oid, b_mode,
+				 _("rename"), _("renamed")))
+		return -1;
 
+	if (o->call_depth)
+		return remove_file_from_cache(dest->path);
+	else
+		return update_stages(dest->path, NULL,
+				     rename_branch == o->branch1 ? dest : NULL,
+				     rename_branch == o->branch1 ? NULL : dest);
 }
 
 static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
@@ -1126,7 +1131,7 @@ static struct diff_filespec *filespec_from_entry(struct diff_filespec *target,
 	return target;
 }
 
-static void handle_file(struct merge_options *o,
+static int handle_file(struct merge_options *o,
 			struct diff_filespec *rename,
 			int stage,
 			struct rename_conflict_info *ci)
@@ -1136,6 +1141,7 @@ static void handle_file(struct merge_options *o,
 	const char *cur_branch, *other_branch;
 	struct diff_filespec other;
 	struct diff_filespec *add;
+	int ret;
 
 	if (stage == 2) {
 		dst_entry = ci->dst_entry1;
@@ -1150,7 +1156,8 @@ static void handle_file(struct merge_options *o,
 	add = filespec_from_entry(&other, dst_entry, stage ^ 1);
 	if (add) {
 		char *add_name = unique_path(o, rename->path, other_branch);
-		update_file(o, 0, &add->oid, add->mode, add_name);
+		if (update_file(o, 0, &add->oid, add->mode, add_name))
+			return -1;
 
 		remove_file(o, 0, rename->path, 0);
 		dst_name = unique_path(o, rename->path, cur_branch);
@@ -1161,17 +1168,20 @@ static void handle_file(struct merge_options *o,
 			       rename->path, other_branch, dst_name);
 		}
 	}
-	update_file(o, 0, &rename->oid, rename->mode, dst_name);
-	if (stage == 2)
-		update_stages(rename->path, NULL, rename, add);
+	if ((ret = update_file(o, 0, &rename->oid, rename->mode, dst_name)))
+		; /* fall through, do allow dst_name to be released */
+	else if (stage == 2)
+		ret = update_stages(rename->path, NULL, rename, add);
 	else
-		update_stages(rename->path, NULL, add, rename);
+		ret = update_stages(rename->path, NULL, add, rename);
 
 	if (dst_name != rename->path)
 		free(dst_name);
+
+	return ret;
 }
 
-static void conflict_rename_rename_1to2(struct merge_options *o,
+static int conflict_rename_rename_1to2(struct merge_options *o,
 					struct rename_conflict_info *ci)
 {
 	/* One file was renamed in both branches, but to different names. */
@@ -1194,14 +1204,16 @@ static void conflict_rename_rename_1to2(struct merge_options *o,
 				 &a->oid, a->mode,
 				 &b->oid, b->mode,
 				 ci->branch1, ci->branch2, &mfi))
-			return;
+			return -1;
+
 		/*
 		 * 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.
 		 */
-		update_file(o, 0, &mfi.oid, mfi.mode, one->path);
+		if (update_file(o, 0, &mfi.oid, mfi.mode, one->path))
+			return -1;
 
 		/*
 		 * Above, we put the merged content at the merge-base's
@@ -1212,22 +1224,26 @@ static void conflict_rename_rename_1to2(struct merge_options *o,
 		 * resolving the conflict at that path in its favor.
 		 */
 		add = filespec_from_entry(&other, ci->dst_entry1, 2 ^ 1);
-		if (add)
-			update_file(o, 0, &add->oid, add->mode, a->path);
+		if (add) {
+			if (update_file(o, 0, &add->oid, add->mode, a->path))
+				return -1;
+		}
 		else
 			remove_file_from_cache(a->path);
 		add = filespec_from_entry(&other, ci->dst_entry2, 3 ^ 1);
-		if (add)
-			update_file(o, 0, &add->oid, add->mode, b->path);
+		if (add) {
+			if (update_file(o, 0, &add->oid, add->mode, b->path))
+				return -1;
+		}
 		else
 			remove_file_from_cache(b->path);
-	} else {
-		handle_file(o, a, 2, ci);
-		handle_file(o, b, 3, ci);
-	}
+	} else if (handle_file(o, a, 2, ci) || handle_file(o, b, 3, ci))
+		return -1;
+
+	return 0;
 }
 
-static void conflict_rename_rename_2to1(struct merge_options *o,
+static int conflict_rename_rename_2to1(struct merge_options *o,
 					struct rename_conflict_info *ci)
 {
 	/* Two files, a & b, were renamed to the same thing, c. */
@@ -1238,6 +1254,7 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 	char *path = c1->path; /* == c2->path */
 	struct merge_file_info mfi_c1;
 	struct merge_file_info mfi_c2;
+	int ret;
 
 	output(o, 1, _("CONFLICT (rename/rename): "
 	       "Rename %s->%s in %s. "
@@ -1254,7 +1271,7 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 	    merge_file_special_markers(o, b, &ci->ren2_other, c2,
 				       o->branch1, ci->ren2_other.path,
 				       o->branch2, c2->path, &mfi_c2))
-		return;
+		return -1;
 
 	if (o->call_depth) {
 		/*
@@ -1265,19 +1282,25 @@ static void conflict_rename_rename_2to1(struct merge_options *o,
 		 * again later for the non-recursive merge.
 		 */
 		remove_file(o, 0, path, 0);
-		update_file(o, 0, &mfi_c1.oid, mfi_c1.mode, a->path);
-		update_file(o, 0, &mfi_c2.oid, mfi_c2.mode, b->path);
+		ret = update_file(o, 0, &mfi_c1.oid, mfi_c1.mode, a->path);
+		if (!ret)
+			ret = update_file(o, 0, &mfi_c2.oid, mfi_c2.mode,
+					  b->path);
 	} else {
 		char *new_path1 = unique_path(o, path, ci->branch1);
 		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);
-		update_file(o, 0, &mfi_c1.oid, mfi_c1.mode, new_path1);
-		update_file(o, 0, &mfi_c2.oid, mfi_c2.mode, new_path2);
+		ret = update_file(o, 0, &mfi_c1.oid, mfi_c1.mode, new_path1);
+		if (!ret)
+			ret = update_file(o, 0, &mfi_c2.oid, mfi_c2.mode,
+					  new_path2);
 		free(new_path2);
 		free(new_path1);
 	}
+
+	return ret;
 }
 
 static int process_renames(struct merge_options *o,
@@ -1462,12 +1485,13 @@ static int process_renames(struct merge_options *o,
 				 * update_file_flags() instead of
 				 * update_file().
 				 */
-				update_file_flags(o,
-						  &ren1->pair->two->oid,
-						  ren1->pair->two->mode,
-						  ren1_dst,
-						  1, /* update_cache */
-						  0  /* update_wd    */);
+				if (update_file_flags(o,
+						      &ren1->pair->two->oid,
+						      ren1->pair->two->mode,
+						      ren1_dst,
+						      1, /* update_cache */
+						      0  /* update_wd    */))
+					clean_merge = -1;
 			} else if (!oid_eq(&dst_other.oid, &null_oid)) {
 				clean_merge = 0;
 				try_merge = 1;
@@ -1482,22 +1506,28 @@ static int process_renames(struct merge_options *o,
 							   ren1->pair->two->mode,
 							   &dst_other.oid,
 							   dst_other.mode,
-							   branch1, branch2, &mfi))
-						return -1;
+							   branch1, branch2, &mfi)) {
+						clean_merge = -1;
+						goto cleanup_and_return;
+					}
 					output(o, 1, _("Adding merged %s"), ren1_dst);
-					update_file(o, 0, &mfi.oid,
-						    mfi.mode, ren1_dst);
+					if (update_file(o, 0, &mfi.oid,
+							mfi.mode, ren1_dst))
+						clean_merge = -1;
 					try_merge = 0;
 				} else {
 					char *new_path = unique_path(o, ren1_dst, branch2);
 					output(o, 1, _("Adding as %s instead"), new_path);
-					update_file(o, 0, &dst_other.oid,
-						    dst_other.mode, new_path);
+					if (update_file(o, 0, &dst_other.oid,
+							dst_other.mode, new_path))
+						clean_merge = -1;
 					free(new_path);
 				}
 			} else
 				try_merge = 1;
 
+			if (clean_merge < 0)
+				goto cleanup_and_return;
 			if (try_merge) {
 				struct diff_filespec *one, *a, *b;
 				src_other.path = (char *)ren1_src;
@@ -1524,6 +1554,7 @@ static int process_renames(struct merge_options *o,
 			}
 		}
 	}
+cleanup_and_return:
 	string_list_clear(&a_by_dst, 0);
 	string_list_clear(&b_by_dst, 0);
 
@@ -1586,18 +1617,18 @@ static int blob_unchanged(const struct object_id *o_oid,
 	return ret;
 }
 
-static void handle_modify_delete(struct merge_options *o,
+static int handle_modify_delete(struct merge_options *o,
 				 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)
 {
-	handle_change_delete(o,
-			     path,
-			     o_oid, o_mode,
-			     a_oid, a_mode,
-			     b_oid, b_mode,
-			     _("modify"), _("modified"));
+	return handle_change_delete(o,
+				    path,
+				    o_oid, o_mode,
+				    a_oid, a_mode,
+				    b_oid, b_mode,
+				    _("modify"), _("modified"));
 }
 
 static int merge_content(struct merge_options *o,
@@ -1671,7 +1702,8 @@ static int merge_content(struct merge_options *o,
 		output(o, 1, _("CONFLICT (%s): Merge conflict in %s"),
 				reason, path);
 		if (rename_conflict_info && !df_conflict_remains)
-			update_stages(path, &one, &a, &b);
+			if (update_stages(path, &one, &a, &b))
+				return -1;
 	}
 
 	if (df_conflict_remains) {
@@ -1679,30 +1711,33 @@ static int merge_content(struct merge_options *o,
 		if (o->call_depth) {
 			remove_file_from_cache(path);
 		} else {
-			if (!mfi.clean)
-				update_stages(path, &one, &a, &b);
-			else {
+			if (!mfi.clean) {
+				if (update_stages(path, &one, &a, &b))
+					return -1;
+			} else {
 				int file_from_stage2 = was_tracked(path);
 				struct diff_filespec merged;
 				oidcpy(&merged.oid, &mfi.oid);
 				merged.mode = mfi.mode;
 
-				update_stages(path, NULL,
-					      file_from_stage2 ? &merged : NULL,
-					      file_from_stage2 ? NULL : &merged);
+				if (update_stages(path, NULL,
+						  file_from_stage2 ? &merged : NULL,
+						  file_from_stage2 ? NULL : &merged))
+					return -1;
 			}
 
 		}
 		new_path = unique_path(o, path, rename_conflict_info->branch1);
 		output(o, 1, _("Adding as %s instead"), new_path);
-		update_file(o, 0, &mfi.oid, mfi.mode, new_path);
+		if (update_file(o, 0, &mfi.oid, mfi.mode, new_path)) {
+			free(new_path);
+			return -1;
+		}
 		free(new_path);
 		mfi.clean = 0;
-	} else {
-		update_file(o, mfi.clean, &mfi.oid, mfi.mode, path);
-	}
+	} else if (update_file(o, mfi.clean, &mfi.oid, mfi.mode, path))
+		return -1;
 	return mfi.clean;
-
 }
 
 /* Per entry merge function */
@@ -1730,17 +1765,21 @@ static int process_entry(struct merge_options *o,
 			break;
 		case RENAME_DELETE:
 			clean_merge = 0;
-			conflict_rename_delete(o, conflict_info->pair1,
-					       conflict_info->branch1,
-					       conflict_info->branch2);
+			if (conflict_rename_delete(o,
+						   conflict_info->pair1,
+						   conflict_info->branch1,
+						   conflict_info->branch2))
+				clean_merge = -1;
 			break;
 		case RENAME_ONE_FILE_TO_TWO:
 			clean_merge = 0;
-			conflict_rename_rename_1to2(o, conflict_info);
+			if (conflict_rename_rename_1to2(o, conflict_info))
+				clean_merge = -1;
 			break;
 		case RENAME_TWO_FILES_TO_ONE:
 			clean_merge = 0;
-			conflict_rename_rename_2to1(o, conflict_info);
+			if (conflict_rename_rename_2to1(o, conflict_info))
+				clean_merge = -1;
 			break;
 		default:
 			entry->processed = 0;
@@ -1760,8 +1799,9 @@ static int process_entry(struct merge_options *o,
 		} else {
 			/* Modify/delete; deleted side may have put a directory in the way */
 			clean_merge = 0;
-			handle_modify_delete(o, path, o_oid, o_mode,
-					     a_oid, a_mode, b_oid, b_mode);
+			if (handle_modify_delete(o, path, o_oid, o_mode,
+						 a_oid, a_mode, b_oid, b_mode))
+				clean_merge = -1;
 		}
 	} else if ((!o_oid && a_oid && !b_oid) ||
 		   (!o_oid && !a_oid && b_oid)) {
@@ -1793,14 +1833,16 @@ static int process_entry(struct merge_options *o,
 			output(o, 1, _("CONFLICT (%s): There is a directory with name %s in %s. "
 			       "Adding %s as %s"),
 			       conf, path, other_branch, path, new_path);
-			update_file(o, 0, oid, mode, new_path);
-			if (o->call_depth)
+			if (update_file(o, 0, oid, mode, new_path))
+				clean_merge = -1;
+			else if (o->call_depth)
 				remove_file_from_cache(path);
 			free(new_path);
 		} else {
 			output(o, 2, _("Adding %s"), path);
 			/* do not overwrite file if already present */
-			update_file_flags(o, oid, mode, path, 1, !a_oid);
+			if (update_file_flags(o, oid, mode, path, 1, !a_oid))
+				clean_merge = -1;
 		}
 	} else if (a_oid && b_oid) {
 		/* Case C: Added in both (check for same permissions) and */
@@ -1863,12 +1905,18 @@ int merge_trees(struct merge_options *o,
 		re_head  = get_renames(o, head, common, head, merge, entries);
 		re_merge = get_renames(o, merge, common, head, merge, entries);
 		clean = process_renames(o, re_head, re_merge);
+		if (clean < 0)
+			return clean;
 		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
-				&& !process_entry(o, path, e))
-				clean = 0;
+			if (!e->processed) {
+				int ret = process_entry(o, path, e);
+				if (!ret)
+					clean = 0;
+				else if (ret < 0)
+					return ret;
+			}
 		}
 		for (i = 0; i < entries->nr; i++) {
 			struct stage_data *e = entries->items[i].util;