From a4b71877e4f0b13d2359e33574d241354aae692a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Arpad=20M=C3=BCller?= <arpad-m@users.noreply.github.com>
Date: Sun, 4 Feb 2024 22:56:27 +0100
Subject: [PATCH] S3: Allow in place copies when bucket versioning is enabled
 (#7303)

---
 moto/s3/models.py                   |  5 +--
 tests/test_s3/test_s3_copyobject.py | 52 +++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+), 2 deletions(-)

diff --git a/moto/s3/models.py b/moto/s3/models.py
index 291459bcd..4365f1e19 100644
--- a/moto/s3/models.py
+++ b/moto/s3/models.py
@@ -108,7 +108,7 @@ class FakeKey(BaseModel, ManagedState):
         storage: Optional[str] = "STANDARD",
         etag: Optional[str] = None,
         is_versioned: bool = False,
-        version_id: str = "null",
+        version_id: Optional[str] = None,
         max_buffer_size: Optional[int] = None,
         multipart: Optional["FakeMultipart"] = None,
         bucket_name: Optional[str] = None,
@@ -170,7 +170,7 @@ class FakeKey(BaseModel, ManagedState):
 
     @property
     def version_id(self) -> str:
-        return self._version_id
+        return self._version_id or "null"
 
     @property
     def value(self) -> bytes:
@@ -2674,6 +2674,7 @@ class S3Backend(BaseBackend, CloudWatchMetricProvider):
                     mdirective == "REPLACE",
                     website_redirect_location,
                     bucket.encryption,  # S3 will allow copy in place if the bucket has encryption configured
+                    src_key._version_id and bucket.is_versioned,
                 )
             ):
                 raise CopyObjectMustChangeSomething
diff --git a/tests/test_s3/test_s3_copyobject.py b/tests/test_s3/test_s3_copyobject.py
index 527cda3dd..c734d22c2 100644
--- a/tests/test_s3/test_s3_copyobject.py
+++ b/tests/test_s3/test_s3_copyobject.py
@@ -783,6 +783,58 @@ def test_copy_object_in_place_with_bucket_encryption():
     assert response["ServerSideEncryption"] == "AES256"
 
 
+@mock_aws
+def test_copy_object_in_place_with_versioning():
+    # If a bucket has versioning enabled, it will allow copy in place
+    client = boto3.client("s3", region_name=DEFAULT_REGION_NAME)
+    bucket_name = "testbucket"
+    client.create_bucket(Bucket=bucket_name)
+    key = "source-key"
+
+    response = client.put_object(
+        Body=b"",
+        Bucket=bucket_name,
+        Key=key,
+    )
+
+    response = client.put_bucket_versioning(
+        Bucket=bucket_name,
+        VersioningConfiguration={
+            "MFADelete": "Disabled",
+            "Status": "Enabled",
+        },
+    )
+    assert response["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    response = client.put_object(
+        Body=b"",
+        Bucket=bucket_name,
+        Key=key,
+    )
+    version_id = response["ResponseMetadata"]["HTTPHeaders"]["x-amz-version-id"]
+    assert version_id and version_id != "null"
+
+    response = client.copy_object(
+        Bucket=bucket_name,
+        CopySource={"Bucket": bucket_name, "Key": key, "VersionId": version_id},
+        Key=key,
+    )
+    assert response["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    response = client.copy_object(
+        Bucket=bucket_name,
+        CopySource={"Bucket": bucket_name, "Key": key, "VersionId": "null"},
+        Key=key,
+    )
+    assert response["ResponseMetadata"]["HTTPStatusCode"] == 200
+
+    response = client.list_object_versions(
+        Bucket=bucket_name,
+        Prefix=key,
+    )
+    assert len(response["Versions"]) == 4
+
+
 @mock_aws
 @pytest.mark.parametrize(
     "algorithm",