  We present a combined QCD analysis of recent data produced by the H1 and ZEUS
collaborations on the diffractive and leading-proton deep inelastic
positron--proton scattering structure functions, $F_2^{D(3)}$ and
$F_2^{LP(3)}$, respectively. It is shown that the QCD framework for
semi-inclusive processes, based on fracture functions, allows a unified
treatment of both diffractive and leading-proton processes, and offers a
precise perturbative QCD description for them, alternative to those that rely
on model-dependent assumptions, such as Regge factorization, or other
non-perturbative approaches
