2015.06.11 18:14 "Re: [Tiff] Libtiff 4.0.4 release soon", by Bob Friesenhahn
I have not checked the libtiff bug tracker. Others have applied some patches/changes to libtiff (I have not checked which ones).
I haven't tested any of those patches, but my sentiment is that's what "beta" release-cycle periods (like this one) are for.
We have too much time between libtiff releases and have spent too much time on a "beta" release cycle.
It would be better to have a new formal libtiff every several months (which can incorporate all applied fixes) rather than waste time on useless betas. The beta releases do not get enough actual use to be useful.
Regardless, it should be possible to apply a number of patches before this forthcoming release.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/