From 79addb8926a14db5146bb44ab60a2221bb6b699a Mon Sep 17 00:00:00 2001
From: Steve Pulec <spulec@gmail.com>
Date: Thu, 5 May 2016 22:52:12 -0400
Subject: [PATCH] Add S3 functionality to copy range. Closes #526.

---
 moto/s3/models.py        |  7 +++++--
 moto/s3/responses.py     | 10 +++++++++-
 tests/test_s3/test_s3.py |  4 ++--
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/moto/s3/models.py b/moto/s3/models.py
index 685254eba..c6baa3f79 100644
--- a/moto/s3/models.py
+++ b/moto/s3/models.py
@@ -438,12 +438,15 @@ class S3Backend(BaseBackend):
         return multipart.set_part(part_id, value)
 
     def copy_part(self, dest_bucket_name, multipart_id, part_id,
-                  src_bucket_name, src_key_name):
+                  src_bucket_name, src_key_name, start_byte, end_byte):
         src_key_name = clean_key_name(src_key_name)
         src_bucket = self.get_bucket(src_bucket_name)
         dest_bucket = self.get_bucket(dest_bucket_name)
         multipart = dest_bucket.multiparts[multipart_id]
-        return multipart.set_part(part_id, src_bucket.keys[src_key_name].value)
+        src_value = src_bucket.keys[src_key_name].value
+        if start_byte is not None:
+            src_value = src_value[start_byte:end_byte + 1]
+        return multipart.set_part(part_id, src_value)
 
     def prefix_query(self, bucket, prefix, delimiter):
         key_results = set()
diff --git a/moto/s3/responses.py b/moto/s3/responses.py
index d465f2432..700561035 100644
--- a/moto/s3/responses.py
+++ b/moto/s3/responses.py
@@ -409,9 +409,17 @@ class ResponseObject(_TemplateEnvironmentMixin):
             if 'x-amz-copy-source' in request.headers:
                 src = request.headers.get("x-amz-copy-source")
                 src_bucket, src_key = src.split("/", 1)
+                src_range = request.headers.get('x-amz-copy-source-range', '').split("bytes=")[-1]
+
+                try:
+                    start_byte, end_byte = src_range.split("-")
+                    start_byte, end_byte = int(start_byte), int(end_byte)
+                except ValueError:
+                    start_byte, end_byte = None, None
+
                 key = self.backend.copy_part(
                     bucket_name, upload_id, part_number, src_bucket,
-                    src_key)
+                    src_key, start_byte, end_byte)
                 template = self.response_template(S3_MULTIPART_UPLOAD_RESPONSE)
                 response = template.render(part=key)
             else:
diff --git a/tests/test_s3/test_s3.py b/tests/test_s3/test_s3.py
index f37096bb1..25668400c 100644
--- a/tests/test_s3/test_s3.py
+++ b/tests/test_s3/test_s3.py
@@ -156,9 +156,9 @@ def test_multipart_upload_with_copy_key():
     multipart = bucket.initiate_multipart_upload("the-key")
     part1 = b'0' * REDUCED_PART_SIZE
     multipart.upload_part_from_file(BytesIO(part1), 1)
-    multipart.copy_part_from_key("foobar", "original-key", 2)
+    multipart.copy_part_from_key("foobar", "original-key", 2, 0, 3)
     multipart.complete_upload()
-    bucket.get_key("the-key").get_contents_as_string().should.equal(part1 + b"key_value")
+    bucket.get_key("the-key").get_contents_as_string().should.equal(part1 + b"key_")
 
 
 @mock_s3