rails/rails — comment on commit 9d87a67590c05114d88eccd6a856d2f054860cdb
File:  line 0
By josevalim:

Bro, we are freezing the hash otherwise Ruby is going to dup it internally in order to use it as key. Since _set_detail is unlikely to be called after the first template is rendered, the freeze version should perform better. amirite?