S3BotoStorage doesn't properly fallback to other Content-Type heuristics

[bxm156]

Content Type is determined by the following:

1. a property called content-type
2. the filename
3. a default is used

If the content-type property doesn't exist, the logic falls back to 2 and 3. But the logic doesn't properly fallback if the content_type exists, but it set to None.

I found that in django my InMemoryFileUpload had a content_type of None. And so django-storages would try to make a s3 upload via boto3 with the following params {"Content-Type:": None}

This would cause boto to crash with

Invalid type for parameter ContentType, value: None, type: <class 'NoneType'>, valid types: <class 'str'>

[alexhayes]

@bxm156 Are you using django-filer to upload the file in the admin?

[willplaehn]

I encountered this issue today using the s3boto3 backend when dealing with a certain .ico file and reached the same conclusion as the OP. I'm not using django-filer

s3boto3.py 421

        _type, encoding = mimetypes.guess_type(name)
        content_type = getattr(content, 'content_type',
                               _type or self.default_content_type)

Could be changed to something like the following. Keeping the linebreaks for easier comparison:

        _type, encoding = mimetypes.guess_type(name)
        content_type = getattr(content, 'content_type',
                               None) or _type or self.default_content_type

What do you think?

[bxm156]

@alexhayes Yes, I was using django-filer. However it seems like @willplaehn is not.

[Alir3z4]

I'm using Django Filler as well, and this is happening for me as well