missing ActualObjectSize in s3.Object.get() response when requesting partial content with excess length

[jcushman]

When s3.Object.get() is called with an invalid range header, the Error response dict is missing the ActualObjectSize value, which is necessary to handle the error in client code.

For an example of why this response value is useful, see this smart_open PR, where ActualObjectSize is needed to avoid redundant API queries during seek().

This issue is related to #2964, but I am filing separately since that one could easily be fixed without fixing this one.

Expected behavior using live S3

In [1]: import boto3, botocore

In [3]: from pprint import pprint

In [4]: try:
   ...:     boto3.resource('s3').Object('mybucket', 'test.txt').get(Range="bytes=10000-")
   ...: except botocore.client.ClientError as e:
   ...:     pprint(e.response)
   ...:
{'Error': {'ActualObjectSize': '4',
           'Code': 'InvalidRange',
           'Message': 'The requested range is not satisfiable',
           'RangeRequested': 'bytes=10000-'},
 'ResponseMetadata': {'HTTPHeaders': {'content-type': 'application/xml',
                                      'date': 'Sun, 10 May 2020 18:14:10 GMT',
                                      'server': 'AmazonS3',
                                      'transfer-encoding': 'chunked',
                                      'x-amz-id-2': '...',
                                      'x-amz-request-id': '...'},
                      'HTTPStatusCode': 416,
                      'HostId': '...',
                      'RequestId': '...',
                      'RetryAttempts': 1}}

moto behavior

In [6]: with mock_s3():
   ...:     ...
   ...:     try:
   ...:         boto3.resource('s3').Object('mybucket', 'test.txt').get(Range="bytes=10000-")
   ...:     except botocore.client.ClientError as e:
   ...:         pprint(e.response)
   ...:
{'Error': {'Code': '416', 'Message': 'Requested Range Not Satisfiable'},
 'ResponseMetadata': {'HTTPHeaders': {},
                      'HTTPStatusCode': 416,
                      'HostId': '',
                      'RequestId': '',
                      'RetryAttempts': 0}}

Versions

moto==1.3.14, master
boto==2.49.0
boto3==1.13.0
botocore==1.16.0

[bblommers]

This is now partof moto >= 1.3.16.dev79