subrepo: replace direct file APIs around "readlines" by "vfs.tryreadlines" This patch also replaces "self._getstorehashcachepath" (building absolute path up) by "self._getstorehashcachename" (building relative path up), because "vfs.tryreadlines" requires relative path. This patch makes "_readstorehashcache()" return "[]" (returned by "vfs.tryreadlines()"), when cache file doesn't exist, even though "_readstorehashcache()" returned '' (empty string) in such case before this patch. "_readstorehashcache()" is invoked only by the code path below in "_storeclean()": for filehash in self._readstorehashcache(path): if filehash != itercache.next(): clean = False break In this case, "[]" and '' don't differ from each other, because both of them cause avoiding iteration of "for loop".