Git alias:
remote-ref = !"sh -c ' \
local_ref=$(git symbolic-ref HEAD); \
local_name=${local_ref##refs/heads/}; \
remote=$(git config branch.\"#local_name\".remote || echo origin); \
remote_ref=$(git config branch.\"$local_name\".merge); \
remote_name=${remote_ref##refs/heads/}; \
echo remotes/$remote/$remote_name'"
Example:
git remote-ref
Thanks to jtolds on stackoverflow