Resize AIFF / WAVE files to reported data size

[phw]

Some AIFF / WAVE files have smaller actual file size then the reported size of their chunks, as trailing null bytes are sometimes truncated.

This patch ensures the chunks fit the file before saving it.

Fixes #496

See also discussion at https://community.metabrainz.org/t/receiving-valueerror-when-saving-some-files/502884/2

[phw]

Similar reported at https://community.metabrainz.org/t/red-sign-error-on-varying-number-of-tracks-ripped-from-cds/524059

[phw]

Failing tests seem to be unrelated, some TAK test takes longer than expected.

[lazka]

hmmm, isn't this a security issue? with the source file dictating how much data we write, potentially a lot

[phw]

Mmh, maybe. Any other idea how to solve this then?

The majority of cases seems to miss exactly one byte at the end, as a result of the last chunk having an uneven data size and some tools seem to write files with the last padding byte missing. We could limit the check for this case only.

But I have seen at least one case where a larger chunk of the file was missing, probably the implementation omitted all null bytes at the end (at least the existing data seemed to be complete and adding the proper number of null bytes worked).

[phw]

Maybe instead:

• Detect if the last chunk claimed size would exceed the file length and adjust its size field to the max. possible (there isn't more data anyway) without changing file size
• Handle only missing padding byte at the end of the file (I still think it should actually add it to the file when saving)

[phw]

@lazka I added #517 for an alternative approach, which avoids trusting the file size and resizing the file.

Closing this PR