rgw: fetch_remote_obj() preserves RGW_ATTR_COMPRESSION of encrypted objects

if the source object was both compressed and encrypted, preserve its
original compression attribute so it can be decompressed the same way it
was originally compressed

Signed-off-by: Casey Bodley <[email protected]>

Author: cbodley

src/rgw/driver/rados/rgw_rados.cc

@@ -3402,8 +3402,12 @@ class RGWRadosPutObj : public RGWHTTPStreamRWRequest::ReceiveCB
         try_etag_verify = false;
       }
 
+      // if the object is both compressed and encrypted, it was transferred
+      // in its encrypted+compressed form. we need to preserve the original
+      // RGW_ATTR_COMPRESSION instead of falling back to default compression
+      // settings
       auto iter = src_attrs.find(RGW_ATTR_COMPRESSION);
-      if (iter != src_attrs.end()) {
+      if (iter != src_attrs.end() && !encrypted) {
         const bufferlist bl = std::move(iter->second);
         src_attrs.erase(iter); // don't preserve source compression info