+/**
+ * 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)