Allow the content-length header to be missing

[davehunt]

Currently we fail if the content-length header is not present:

$ mozdownload --url=https://github.com/status
INFO | Downloading from: https://github.com/status
Traceback (most recent call last):
File "/Users/dhunt/.virtualenvs/mozdownload/bin/mozdownload", line 8, in
load_entry_point('mozdownload==1.10', 'console_scripts', 'mozdownload')()
File "/Users/dhunt/workspace/mozdownload/mozdownload/scraper.py", line 1016, in cli
build.download()
File "/Users/dhunt/workspace/mozdownload/mozdownload/scraper.py", line 277, in download
total_size = int(r.headers.get('Content-length').strip())
AttributeError: 'NoneType' object has no attribute 'strip'

We need a test and a fix for this.

[whimboo]

Good catch. I hope that we don't have to do too much workarounds for the progress bar to be working. @Nebelhom, mind having a look at, given that you mostly implemented this code?

[Nebelhom]

@whimboo @davehunt

What should be the expected behaviour in this instance?

[davehunt]

We shouldn't throw an exception. We should download the file. :)

[whimboo]

PR #198 has been fixed. Thanks!