Revert change to testing md5 in sqs

gems/aws-sdk-s3/lib/aws-sdk-s3/plugins/md5s.rb

@@ -60,15 +60,26 @@ def update_in_chunks(digest, io)
         end
 
         option(:compute_checksums,
-          default: true,
           doc_type: 'Boolean',
-          docstring: <<-DOCS)
+          docstring: <<-DOCS
 When `true` a MD5 checksum will be computed and sent in the Content Md5
 header for :put_object and :upload_part. When `false`, MD5 checksums
 will not be computed for these operations. Checksums are still computed
 for operations requiring them. Checksum errors returned by Amazon S3 are
 automatically retried up to `:retry_limit` times.
           DOCS
+        ) do |config|
+          # By default, we will disable checksum verification when response
+          # stubbing is enable. If a user decides to enable both features,
+          # then they will need to stub the MD5s in the response.
+          # See the spec/aws/sqs/client/verify_checksums_spec.rb for
+          # examples of how to do this.
+          if config.respond_to?(:stub_responses)
+            !config.stub_responses
+          else
+            config.verify_checksums
+          end
+        end
 
         def add_handlers(handlers, config)
           if config.compute_checksums

gems/aws-sdk-sqs/spec/client/verify_checksums_spec.rb

@@ -59,6 +59,16 @@ class Client
           expect(client.config.verify_checksums).to be(true)
         end
 
+        it 'is disabled when response stubbing is enabled' do
+          client = Client.new(stub_responses: true)
+          expect(client.config.verify_checksums).to be(false)
+        end
+
+        it 'can be enabled with response stubbing is enabled' do
+          client = Client.new(stub_responses: true, verify_checksums: true)
+          expect(client.config.verify_checksums).to be(true)
+        end
+
         describe '#send_message' do
           let(:md5_of_attributes) { '756d7f4338696745d063b420a2f7e502' }
           let(:md5_of_system_attributes) { '756d7f4338696745d063b420a2f7e502' }