When userinfo returns a picture without an extension we don't have accurate content type information. When used in conjunction with the s3fs project (which uses drupals file mime type guess) we end up uploading to Amazon S3 with application/octet-stream content type which breaks the picture.
Detect headers from file_get_contents and add an extension if one isn't present. I have a patch which does this to solve my current needs but haven't tested all cases.
Needs review
2.0
Code
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