Handle mailmap in git listing

This change was made a long while back, but was apparently never committed.

git/list

@@ -20,6 +20,12 @@
 #  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 # #
 
-# add an extra newline to prevent read from getting confused
+# Add an extra newline to prevent read from getting confused.  The dir
+# change is because Git has trouble finding .mailmap.
 t=$'\t'
-git log --first-parent --pretty="format:%H$t%h$t%at$t%f$t%aN$t%aE$t%s" && echo
+(
+  cd "$GIT_DIR/.." \
+    && git log --use-mailmap \
+      --first-parent \
+      --pretty="format:%H$t%h$t%at$t%f$t%aN$t%aE$t%s" && echo
+)