Memoize doesn't take into account all args if using args unpacking about flask-caching

[aktech]

Just had a look at code, It seems the issue is with cache key creation. The cache key created for args (5, 2) and (5, 3) are same.

The root cause is with the _memoize_kwargs_to_args function, it simply ignores the unnamed functions args for e.g. In def foo(a, b, c, *args): pass only the args a, b, c would be used for key and *args is ignored. Similarly in def foo(*args): pass no args is detected.

The reason behind this is that it uses the inpect module to get arg names from function signature, now since *args are not named in function signature, its not found.

The simple solution is to append the unnamed args in the new_args list before creating the key.

https://github.com/sh4nks/flask-caching/blob/c964143616ec484f9ef9ce359f89500fdf60f23a/flask_caching/__init__.py#L522-L582

[aktech]

Tested on Python 3.5.4 on master, doesn't works as well.