fix partial body download

lib/cocoapods-core/cdn_source.rb

@@ -384,7 +384,7 @@ def download_and_save_with_retries_async(partial_url, file_remote_url, etag, ret
       path = repo + partial_url
       etag_path = path.sub_ext(path.extname + '.etag')
 
-      download_impl_async(file_remote_url, etag, :context => context) do |response|
+      download_impl_async(file_remote_url, etag, :context => context) do |response, body|
         case response.status
         when 301
           redirect_location = response.headers['location']
@@ -398,7 +398,6 @@ def download_and_save_with_retries_async(partial_url, file_remote_url, etag, ret
           partial_url
         when 200
           File.open(path, 'w') do |f|
-            body = response.body.read
             encoding = response.headers['content-encoding'].to_s
             if encoding.present?
               case encoding
@@ -475,7 +474,16 @@ def download_impl_async(file_remote_url, etag = nil, context: nil)
       method.call do |task|
         task.with_timeout(REQUEST_TIMEOUT) do
           response = http_client.get file_remote_url, headers
-          yield response if block_given?
+
+          body = nil
+          if response.body
+            body = ''
+            while chunk = response.body.read
+              body << chunk
+            end
+          end
+
+          yield response, body
         ensure
           response&.close
         end