unpack-trees: fix nested sparse-dir search

The iterated search in find_cache_entry() was recently modified to
include a loop that searches backwards for a sparse directory entry that
matches the given traverse_info and name_entry. However, the string
comparison failed to actually concatenate those two strings, so this
failed to find a sparse directory when it was not a top-level directory.

This caused some errors in rare cases where a 'git checkout' spanned a
diff that modified files within the sparse directory entry, but we could
not correctly find the entry.

Helped-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
Helped-by: René Scharfe <l.s.r@web.de>
Signed-off-by: Derrick Stolee <dstolee@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/unpack-trees.c b/unpack-trees.c
index 5786645f315d51be62badb5faa8cb5b8d26f70d2..b78d7ee6c0908145a0524db91e38223279831105 100644 (file)
--- a/unpack-trees.c
+++ b/unpack-trees.c
@@ -1255,7 +1255,7 @@ static int sparse_dir_matches_path(const struct cache_entry *ce,
 static struct cache_entry *find_cache_entry(struct traverse_info *info,
                                            const struct name_entry *p)
 {
-       struct cache_entry *ce;
+       const char *path;
        int pos = find_cache_pos(info, p->path, p->pathlen);
        struct unpack_trees_options *o = info->data;
 
@@ -1281,9 +1281,11 @@ static struct cache_entry *find_cache_entry(struct traverse_info *info,
         * paths (e.g. "subdir-").
         */
        while (pos >= 0) {
-               ce = o->src_index->cache[pos];
+               struct cache_entry *ce = o->src_index->cache[pos];
 
-               if (strncmp(ce->name, p->path, p->pathlen))
+               if (!skip_prefix(ce->name, info->traverse_path, &path) ||
+                   strncmp(path, p->path, p->pathlen) ||
+                   path[p->pathlen] != '/')
                        return NULL;
 
                if (S_ISSPARSEDIR(ce->ce_mode) &&