regexp: considers "\Q\E*" as valid regexp (original) (raw)

Regexp package successfully compiles "\Q\E_", while re2 says:
re2/re2.cc:202: Error parsing '\Q\E_': no argument for repetition operator: *

Who is right here? What is the reason for difference?

go version devel +b0532a9 Mon Jun 8 05:13:15 2015 +0000 linux/amd64