xfuncname not working in my .gitconfig file?

I know that there is a question with same title: Why isn't my xfuncname working in my .gitconfig file?. But it didn't solve my problem.

This is my .attributes file:

*.drd diff=drd

This is my config file:

[diff "drd"]    textconv = echo hi    xfuncname = "^.*$"

This is the diff output:

diff --git a/pool/occ.drd b/pool/occ.drdindex e71f8f3..fd07e44 100644--- a/pool/occ.drd+++ b/pool/occ.drd@@ -1 +1 @@-hi /tmp/XkCI8G_occ.drd+hi /tmp/TEt4oH_occ.drd

Git is correctly recognizing 'textconv' attribute. But it is failing to recognize 'xfuncname'. I'm not sure why. Can someone please help me.

Git version: git version 2.7.4