I think this should fix it.

*** Makefile.in 2013-01-01 09:11:05 +0000
--- Makefile.in 2013-01-16 01:00:14 +0000
***************
*** 534,539 ****
--- 534,540 ----
               tar -xvf - && cat > /dev/null) || exit 1; \
          [ "$${dir}" != "${srcdir}/etc" ] || rm -f $${dest}/DOC* ; \
          for subdir in `find $${dest} -type d -print` ; do \
+           chmod a+rx $${subdir} ; \
            rm -f $${subdir}/.gitignore ; \
            rm -f $${subdir}/.arch-inventory ; \
            rm -f $${subdir}/.DS_Store ; \
***************
*** 568,574 ****
            done )
        -chmod -R a+r $(DESTDIR)${datadir}/emacs/${version} ${COPYDESTS}

! # The last chmod isn't needed at present.

  ## We install only the relevant DOC file if possible
  ## (ie DOC-${version}.buildnumber), otherwise DOC-${version}*.
--- 569,577 ----
            done )
        -chmod -R a+r $(DESTDIR)${datadir}/emacs/${version} ${COPYDESTS}

! ## The above chmods are needed because "umask 022; tar ..." is not
! ## guaranteed to do the right thing; eg if we are root and tar is
! ## preserving source permissions.

  ## We install only the relevant DOC file if possible
  ## (ie DOC-${version}.buildnumber), otherwise DOC-${version}*.