At least 5.0.1 looks to work fine for me since released, not sure if newer versions would be better candidates :/
Arches, please stabilize =app-text/qpdf-5.1.1
Stable for HPPA.
arm stable
amd64 stable
x86 stable
ppc stable
Stable on alpha.
ppc64 stable
sparc stable
ia64 stable. Closing.