+ if (pos < 0)
+ pos = -pos-1;
+ while (pos < active_nr) {
+ struct cache_entry *ce = active_cache[pos++];
+ unsigned char endchar;
+
+ if (strncmp(ce->name, dirname, len))
+ break;
+ endchar = ce->name[len];
+ if (endchar > '/')
+ break;
+ if (endchar == '/')
+ return index_directory;
+ if (!endchar && S_ISDIRLNK(ntohl(ce->ce_mode)))
+ return index_gitdir;
+ }
+ return index_nonexistent;
+}
+
+/*
+ * When we find a directory when traversing the filesystem, we
+ * have three distinct cases:
+ *
+ * - ignore it
+ * - see it as a directory
+ * - recurse into it
+ *
+ * and which one we choose depends on a combination of existing
+ * git index contents and the flags passed into the directory
+ * traversal routine.
+ *
+ * Case 1: If we *already* have entries in the index under that
+ * directory name, we always recurse into the directory to see
+ * all the files.
+ *
+ * Case 2: If we *already* have that directory name as a gitlink,
+ * we always continue to see it as a gitlink, regardless of whether
+ * there is an actual git directory there or not (it might not
+ * be checked out as a subproject!)
+ *
+ * Case 3: if we didn't have it in the index previously, we
+ * have a few sub-cases:
+ *
+ * (a) if "show_other_directories" is true, we show it as
+ * just a directory, unless "hide_empty_directories" is
+ * also true and the directory is empty, in which case
+ * we just ignore it entirely.
+ * (b) if it looks like a git directory, and we don't have
+ * 'no_dirlinks' set we treat it as a gitlink, and show it
+ * as a directory.
+ * (c) otherwise, we recurse into it.
+ */
+enum directory_treatment {
+ show_directory,
+ ignore_directory,
+ recurse_into_directory,
+};
+
+static enum directory_treatment treat_directory(struct dir_struct *dir,
+ const char *dirname, int len,
+ const struct path_simplify *simplify)
+{
+ /* The "len-1" is to strip the final '/' */
+ switch (directory_exists_in_index(dirname, len-1)) {
+ case index_directory:
+ return recurse_into_directory;
+
+ case index_gitdir:
+ return show_directory;
+
+ case index_nonexistent:
+ if (dir->show_other_directories)
+ break;
+ if (!dir->no_dirlinks) {
+ unsigned char sha1[20];
+ if (resolve_gitlink_ref(dirname, "HEAD", sha1) == 0)
+ return show_directory;
+ }
+ return recurse_into_directory;
+ }
+
+ /* This is the "show_other_directories" case */
+ if (!dir->hide_empty_directories)
+ return show_directory;
+ if (!read_directory_recursive(dir, dirname, dirname, len, 1, simplify))
+ return ignore_directory;
+ return show_directory;