Merge branch 'dt/empty-submodule-in-merge' into maint

An empty directory in a working tree that can simply be nuked used
to interfere while merging or cherry-picking a change to create a
submodule directory there, which has been fixed..

* dt/empty-submodule-in-merge:
  submodules: allow empty working-tree dirs in merge/cherry-pick

merge-recursive.c

@@ -664,7 +664,13 @@ static char *unique_path(struct merge_options *o, const char *path, const char *
 	return strbuf_detach(&newpath, NULL);
 }
 
-static int dir_in_way(const char *path, int check_working_copy)
+/**
+ * Check whether a directory in the index is in the way of an incoming
+ * file.  Return 1 if so.  If check_working_copy is non-zero, also
+ * check the working directory.  If empty_ok is non-zero, also return
+ * 0 in the case where the working-tree dir exists but is empty.
+ */
+static int dir_in_way(const char *path, int check_working_copy, int empty_ok)
 {
 	int pos;
 	struct strbuf dirpath = STRBUF_INIT;
@@ -684,7 +690,8 @@ static int dir_in_way(const char *path, int check_working_copy)
 	}
 
 	strbuf_release(&dirpath);
-	return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode);
+	return check_working_copy && !lstat(path, &st) && S_ISDIR(st.st_mode) &&
+		!(empty_ok && is_empty_dir(path));
 }
 
 static int was_tracked(const char *path)
@@ -1062,7 +1069,7 @@ static int handle_change_delete(struct merge_options *o,
 {
 	char *renamed = NULL;
 	int ret = 0;
-	if (dir_in_way(path, !o->call_depth)) {
+	if (dir_in_way(path, !o->call_depth, 0)) {
 		renamed = unique_path(o, path, a_oid ? o->branch1 : o->branch2);
 	}
 
@@ -1195,7 +1202,7 @@ static int handle_file(struct merge_options *o,
 		remove_file(o, 0, rename->path, 0);
 		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, 0)) {
 			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);
@@ -1704,7 +1711,8 @@ 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,
+			       S_ISGITLINK(pair1->two->mode)))
 			df_conflict_remains = 1;
 	}
 	if (merge_file_special_markers(o, &one, &a, &b,
@@ -1862,7 +1870,8 @@ static int process_entry(struct merge_options *o,
 			oid = b_oid;
 			conf = _("directory/file");
 		}
-		if (dir_in_way(path, !o->call_depth)) {
+		if (dir_in_way(path, !o->call_depth,
+			       S_ISGITLINK(a_mode))) {
 			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. "

t/t3030-merge-recursive.sh

@@ -575,13 +575,13 @@ test_expect_success 'merge removes empty directories' '
 	test_must_fail test -d d
 '
 
-test_expect_failure 'merge-recursive simple w/submodule' '
+test_expect_success 'merge-recursive simple w/submodule' '
 
 	git checkout submod &&
 	git merge remove
 '
 
-test_expect_failure 'merge-recursive simple w/submodule result' '
+test_expect_success 'merge-recursive simple w/submodule result' '
 
 	git ls-files -s >actual &&
 	(

t/t3426-rebase-submodule.sh

@@ -38,9 +38,6 @@ git_rebase_interactive () {
 	git rebase -i "$1"
 }
 
-KNOWN_FAILURE_NOFF_MERGE_DOESNT_CREATE_EMPTY_SUBMODULE_DIR=1
-# The real reason "replace directory with submodule" fails is because a
-# directory "sub1" exists, but we reuse the suppression added for merge here
 test_submodule_switch "git_rebase_interactive"
 
 test_done