[RESEND PATCH 2/2] erofs-utils: lib: honor rebuild whiteouts for recreated dirs

When rebuilding from upper to lower, a whiteout below an already
recreated directory should keep that directory but stop older lower
entries from being merged into it.

Mark the existing directory opaque before applying the generic
non-directory bailout.

Reported-by: cayoub-oai <[email protected]>
Closes: https://github.com/erofs/erofs-utils/issues/49
Assisted-by: Codex:GPT-5.5
Signed-off-by: Yifan Zhao <[email protected]>
---
 lib/rebuild.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lib/rebuild.c b/lib/rebuild.c
index 51dfe18..108a464 100644
--- a/lib/rebuild.c
+++ b/lib/rebuild.c
@@ -401,7 +401,13 @@ static int erofs_rebuild_dirent_iter(struct erofs_dir_context *ctx)
 			.nid = ctx->de_nid
 		};
 		ret = erofs_read_inode_from_disk(&src);
-		if (ret || !S_ISDIR(src.i_mode))
+		if (ret)
+			goto out;
+		if (erofs_inode_is_whiteout(&src)) {
+			d->inode->opaque = true;
+			goto out;
+		}
+		if (!S_ISDIR(src.i_mode))
 			goto out;
 		mergedir = d->inode;
 		inode = dir = &src;
-- 
2.47.3