xml2-config error in makefile

xml2-config --cflags in some architectures (mandrake, probably redhat
and suse) is returning only:

-I/usr/include/libxml2


In debian, I have in changelogs: 


libxml2 (2.4.19-2) unstable; urgency=low

  * (...)
  * xml2-config --cflags will return same paths as previous versions
    (closes: #142229)

And xml2-config returns correctly:
-I/usr/include/libxml2/libxml -I/usr/include/libxml2

Shouldn't we be aware of that in configure and detect
if it needs to add libxml ?