2012.01.22 18:18 "Re: [Tiff] update on tiff 4.x in debian", by Bob Friesenhahn
Bummer. I will look into doing this based on the approach used for libjpeg. It would have been good if this had been implemented prior to the 4.0.0 release. Now we are faced with the situation that an application built against a libtiff which does not use versioned symbols will stop working if a libtiff which uses versioned symbols is inserted in its place. A defense against that is to increment 'current' and leave 'age' set to zero for the newer library since the whole interface has changed. I am not particularly religious about library file names but others may be disturbed by such changes.
We have the option to make versioned symbols optional, and defaulting to off. Libjpeg 8 enabled them by default, but it started off using versioned symbols. We also have the option to add versioned symbols by default, and warn that libjpeg 4.0.0 users will need to relink existing applications. This would cause problems for any distributions already using 4.0.0.
It is a bit of a problem/annoyance that creating the library with versioned symbols depends on the GNU linker. A system might have both the GNU linker, and a system-provided (non-GNU) linker. If the GNU linker is used, then the library happens to have versioned symbols, otherwise not.
Between Linux and FreeBSD, 'objdump --dynamic-syms' shows the same versioning information (for libjpeg) even though the library file names are dramatically different.
GraphicsMagick Maintainer, http://www.GraphicsMagick.org/