[GR-18163] Let Net::HTTP handle decompression when downloading the gem versions index

PullRequest: truffleruby/2183

Author: eregon

lib/mri/bundler/compact_index_client/updater.rb

@@ -47,14 +47,17 @@ def update(local_path, remote_path, retrying = nil)
               end
           else
             # Fastly ignores Range when Accept-Encoding: gzip is set
-            headers["Accept-Encoding"] = "gzip"
+            unless defined?(::TruffleRuby) # let Net::HTTP handle decompression, which is more memory efficient
+              headers["Accept-Encoding"] = "gzip"
+            end
           end
 
           response = @fetcher.call(remote_path, headers)
           return nil if response.is_a?(Net::HTTPNotModified)
 
           content = response.body
           if response["Content-Encoding"] == "gzip"
+            warn "Net::HTTP should have decompressed a gzip-encoded body" if defined?(::TruffleRuby)
             content = Zlib::GzipReader.new(StringIO.new(content)).read
           end