OleFileIO.get_metadata() hangs when parsing some corrupt ole files

[crazyyao0]

Describe the bug
OleFileIO.get_metadata() hangs when parsing some corrupt ole files

File or Malware sample to reproduce the bug
Sample code:

import olefile
ole = olefile.OleFileIO('fc1fe4c124cc42eda492d2714bced597')
ole.get_metadata()

two sample files
samples.zip

How To Reproduce the bug
You can easily reproduce it with the sample code

Expected behavior
It can either return with partial information or raise an exception.

Console output / Screenshots
debug.log

Version information:

• OS: Windows/Linux/Mac/Other
• OS version: x.xx - 32/64 bits
• Python version: 2.7/3.6 - 32/64 bits
• olefile version: 0.47

Additional context

For some reason the count is a very big number. But _parse_property_basic() always return zero size. We need to by pass such loop.

Add any other context about the problem here.