Reading a 0 B file from s3 raises OSError

[rchui]

Problem description

smart_open should be able to read a 0 byte file from s3 without raising an Exception.

Steps/code to reproduce the problem

1. Upload a 0 byte file to s3
2. Use smart_open.open to try to read it:

from smart_open import open

with open('s3://some/random/uri', 'rb') as file:
    file.read()

Traceback

s3.py in read_file(self)
     55         """
     56 
---> 57         with open(self.uri, "rb") as file:
     58             contents: bytes = file.read()
     59         return contents

venv/lib/python3.6/site-packages/smart_open/smart_open_lib.py in open(uri, mode, buffering, encoding, errors, newline, closefd, opener, ignore_ext, transport_params)
    221     #
    222     binary_mode = _TO_BINARY_LUT.get(mode, mode)
--> 223     binary = _open_binary_stream(uri, binary_mode, transport_params)
    224     if ignore_ext:
    225         decompressed = binary

.venv/lib/python3.6/site-packages/smart_open/smart_open_lib.py in _open_binary_stream(uri, mode, transport_params)
    399     scheme = _sniff_scheme(uri)
    400     submodule = transport.get_transport(scheme)
--> 401     fobj = submodule.open_uri(uri, mode, transport_params)
    402     if not hasattr(fobj, 'name'):
    403         logger.critical('TODO')

.venv/lib/python3.6/site-packages/smart_open/s3.py in open_uri(uri, mode, transport_params)
    168     parsed_uri, transport_params = _consolidate_params(parsed_uri, transport_params)
    169     kwargs = smart_open.utils.check_kwargs(open, transport_params)
--> 170     return open(parsed_uri['bucket_id'], parsed_uri['key_id'], mode, **kwargs)
    171 
    172 

.venv/lib/python3.6/site-packages/smart_open/s3.py in open(bucket_id, key_id, mode, version_id, buffer_size, min_part_size, session, resource_kwargs, multipart_upload_kwargs, multipart_upload, singlepart_upload_kwargs, object_kwargs, defer_seek)
    245             resource_kwargs=resource_kwargs,
    246             object_kwargs=object_kwargs,
--> 247             defer_seek=defer_seek,
    248         )
    249     elif mode == constants.WRITE_BINARY:

.venv/lib/python3.6/site-packages/smart_open/s3.py in __init__(self, bucket, key, version_id, buffer_size, line_terminator, session, resource_kwargs, object_kwargs, defer_seek)
    472 
    473         if not defer_seek:
--> 474             self.seek(0)
    475 
    476     #

.venv/lib/python3.6/site-packages/smart_open/s3.py in seek(self, offset, whence)
    567             offset += self._current_pos
    568 
--> 569         self._current_pos = self._raw_reader.seek(offset, whence)
    570         logger.debug('new_position: %r', self._current_pos)
    571 

.venv/lib/python3.6/site-packages/smart_open/s3.py in seek(self, offset, whence)
    355             self._position = self._content_length
    356         else:
--> 357             self._open_body(start, stop)
    358 
    359         return self._position

.venv/lib/python3.6/site-packages/smart_open/s3.py in _open_body(self, start, stop)
    381                 version=self._version_id,
    382                 Range=range_string,
--> 383                 **self._object_kwargs
    384             )
    385         except IOError as ioe:

.venv/lib/python3.6/site-packages/smart_open/s3.py in _get(s3_object, version, **kwargs)
    284         )
    285         wrapped_error.backend_error = error
--> 286         raise wrapped_error from error
    287 
    288 

OSError: unable to access bucket: '<bucket>' key: '<key>' version: None error: An error occurred (InvalidRange) when calling the GetObject operation: The requested range is not satisfiable

Versions

Please provide the output of:

import platform, sys, smart_open
print(platform.platform())
print("Python", sys.version)
print("smart_open", smart_open.__version__)

Darwin-19.6.0-x86_64-i386-64bit
Python 3.6.10 (default, Jun 29 2020, 13:50:05) 
[GCC 4.2.1 Compatible Apple LLVM 11.0.3 (clang-1103.0.32.29)]
smart_open 2.2.1

Checklist

Before you create the issue, please make sure you have:

• Described the problem clearly
• Provided a minimal reproducible example, including any required data
• Provided the version numbers of the relevant software

[Andrew-Sheridan]

Can confirm this is a regression. This error does not occur with version 2.1.0

[Andrew-Sheridan]

Same issue present in version 3.0.0 :/

[piskvorky]

@jcushman could this be related to you #495?