Clarification around parsing `int32` from files

[software-opal]

I'm reviewing your code for a personal project and on Line 109 of the decoder, you create a parser for int32.

It seems to indicate that the type can be shorter(from the pad=True parameter), however in the actual function it reads exactly 4 bytes(type_size) irrespective of the size passed in. This renders the pad option redundant.

My reading of the function implies line 53 should read new_offset = offset + size. Related to this it might also be wise to assert that if pad: assert size <= type_size.

[oschwald]

I think you may be right. A pull request would be welcomed. It would be nice to have a unit test for this. Re: the assert, we should throw an InvalidDatabaseError rather than an AssertionError in this case.

[software-opal]

I will put one together, and yeah I was intending for it to throw the InvalidDatabaseError, I just wanted to make the condition clear