2012.01.23 16:26 "Re: [Tiff] update on tiff 4.x in debian", by Tom Lane
I will get to this as soon as I can, but I will probably want to get someone from the debian release team to look at it. Maybe Tom Lane can look at it too -- he probably has more experience with this than I do.
Sorry, I don't know much of anything about versioned symbols. My reaction TBH is that it's a big mistake to be changing 3.9.x's ABI at this late date, and that if this ships it will be a blocker to ever again updating libtiff 3.9 in existing RHEL branches.
regards, tom lane