My working patch for bug 95708 includes normalize_jamo() in hangul-xft.
Eventually, this routine and associated functions have to be put in a 
sepate file and be made
accessible from rendering functions in both hangul-x.c and hangul-xfs.c.

normalize_jamo() does (copied from bug 95708) :

  - gunichar* normalize_jamo(const gunichar* in, int *len):
    1. Normalize (regularize) a jamo sequence to put it in a regular
       syllable form defined Unicode 3.2 section 3.11 to the extent
       that it's useful in rendering by render_func's().

    2. Replace a compatibly decomposed Jamo sequence (unicode 2.0 
       definition) with a 'precomposed' Jamo cluster (with codepoint
       of its own in U+1100 block). For instance, a seq.
       of U+1100, U+1100 is replaced by U+1101. It actually
       more than Unicode 2.0 decomposition map suggests.
       For a Jamo cluster made up of three basic Jamos
       (e.g. U+1133 : Sios, Piup, Kiyeok), not only
        a sequence of Sios(U+1109), Piup(U+1107) and 
       Kiyeok(U+1100) but also two more sequences,
       {U+1132(Sios-Pieup), U+1100(Kiyeok) and {Sios(U+1109),
        U+111E(Piup-Kiyeok)} are mapped to U+1133.

    3. the result is returned in a newly malloced(g_new'd)
       gunichar*. A calling function has to g_free it.