Open, read and write files in binary mode.

[prsephton]

Paster breaks while copying [some] binary files (copydir.py).

In Python 3, opening files with the "r" flag produces strings on read. To do so, the file content is decoded using utf-8 by default. Some files, like .jpg images may not be valid utf8, and so cause breakage.

This patch suggests that files are always opened and read in binary (rb) mode, and only decoded for processing if we know they are intended to be used templates. Everything else is simply written back as a bytestream.

[cdent]

This seems reasonable.

Is there a simple way to add a test?

[prsephton]

This seems reasonable.

Is there a simple way to add a test?

I think it may be possible to write a unit test using StringIO/BytesIO. One would need to mock everything to do with the directory scan - eg. os.listdir. etc, and file open/close. I am not sure such a test would be all that valid in the end, as it would likely end up being quite complex, possibly buggy and not proving anything worthwhile.

Still, I am open to suggestions if you want a test, and willing to put the effort in if you would like to provide guidance.

[cdent]

Still, I am open to suggestions if you want a test, and willing to put the effort in if you would like to provide guidance.

Not required, was more curiosity than anything else.

I need to fix the GitHub workflows and then can see about merging this. Thanks for the contribution.