Fix for issue #672 (#775)

---------

Co-authored-by: Martin Durant <[email protected]>

s3fs/core.py

@@ -2261,7 +2261,10 @@ def _upload_chunk(self, final=False):
                 Key=key,
             )
 
-            self.parts.append({"PartNumber": part, "ETag": out["ETag"]})
+            part_header = {"PartNumber": part, "ETag": out["ETag"]}
+            if "ChecksumSHA256" in out:
+                part_header["ChecksumSHA256"] = out["ChecksumSHA256"]
+            self.parts.append(part_header)
 
         if self.autocommit and final:
             self.commit()

s3fs/tests/test_s3fs.py

@@ -375,6 +375,35 @@ def test_checksum(s3):
     s3.checksum(path1, refresh=True)
 
 
+def test_multi_checksum(s3):
+    # Moto accepts the request to add checksum, and accepts the checksum mode,
+    # but doesn't actually return the checksum
+    # So, this is mostly a stub test
+    file_key = "checksum"
+    path = test_bucket_name + "/" + file_key
+    s3 = S3FileSystem(
+        anon=False,
+        client_kwargs={"endpoint_url": endpoint_uri},
+        s3_additional_kwargs={"ChecksumAlgorithm": "SHA256"},
+    )
+    with s3.open(
+        path,
+        "wb",
+        blocksize=5 * 2**20,
+    ) as f:
+        f.write(b"0" * (5 * 2**20 + 1))  # starts multipart and puts first part
+        f.write(b"data")  # any extra data
+    assert s3.cat(path) == b"0" * (5 * 2**20 + 1) + b"data"
+    FileHead = sync(
+        s3.loop,
+        s3.s3.head_object,
+        Bucket=test_bucket_name,
+        Key=file_key,
+        ChecksumMode="ENABLED",
+    )
+    # assert "ChecksumSHA256" in FileHead
+
+
 test_xattr_sample_metadata = {"testxattr": "1"}