2004.07.14 16:50 "Re: [Tiff] unintentional ABI change between 3.5 and 3.6?", by Bob Friesenhahn

EXECUTIVE SUMMARY: There are incompatible ABI changes, so the next version of the shared library needs to be 4.0.0. The decision about whether to make the next version of the software 4.0.0 or not also needs to be made, though it is a different decision. Some resolution on whether strong isolation of TIFFRGBAImage (and other structs?) should also be made.

I agree with everything in your posting. I do recommend that an analysis be made of existing OS distributions to make sure that the next libtiff is installed with a high enough version number that it doesn't negatively impact applications already using libtiff. Installing as 4.0.0 may impact FreeBSD or other distributions where the maintainers already took steps to avoid libtiff ABI problems.

>From this time forward, libtiff should use proper ELF/libtool shared library versioning rules and not tie shared library numbering to the release version.

It seems to me that LZW is free for use now, even though IBM holds a similar patent. I am not a lawyer, but (by definition) LZW must be free for use now even though IBM holds a similar patent. Since the LZW patent was issued first, then the IBM patent would be null and void if it is claimed to apply to LZW since two companies can not patent the same invention. Based on this, the next libtiff release should incorporate LZW support by default, and there is no need for a configure option to disable it.

Bob

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Bob Friesenhahn
bfriesen@simple.dallas.tx.us
http://www.simplesystems.org/users/bfriesen