freetype version comparison in spkg-configure.m4 is wrong

[dimpase]

it appears that currently we might accept about any freetype2 coming our way, as our version check is wrong.

$ pkg-config --modversion freetype2
outputs not something sane, but e.g. for freetype version 2.9.1 it is
22.1.6, for 2.10.2 it is 23.2.17
(which is probably some insane value produced following libtool
versioning rules)
while we check for it to be at least 2.4, oops...

CC: @mkoeppe @orlitzky @thierry-FreeBSD @kiwifb @embray

Component: build: configure

Author: Dima Pasechnik

Branch/Commit: u/dimpase/packages/freetype_correct_version @ 168de8b

Reviewer: Matthias Koeppe

Issue created by migration from https://trac.sagemath.org/ticket/30014

[kiwifb]

comment:1

This is completely batty. The version number is supposed to be the libtool number. There is nothing shipped with that number so what's the use. But docs/VERSIONS.TXT has a handy table

    release     libtool     so
  -------------------------------
     2.10.1     23.1.17   6.17.1
     2.10.0     23.0.17   6.17.0
     2.9.1      22.1.16   6.16.1
     2.9.0      22.0.16   6.16.0
     2.8.1	21.0.15   6.15.0
     2.8.0      20.0.14   6.14.0
     2.7.1      19.0.13   6.13.0
     2.7.0	18.6.12   6.12.6
     2.6.5      18.5.12   6.12.5
     2.6.4	18.4.12   6.12.4
     2.6.3      18.3.12   6.12.3
     2.6.2      18.2.12   6.12.2
     2.6.1	18.1.12   6.12.1
     2.6.0      18.0.12   6.12.0
     2.5.5      17.4.11   6.11.4
     2.5.4	17.3.11   6.11.3
     2.5.3      17.2.11   6.11.2
     2.5.2      17.1.11   6.11.1
     2.5.1      17.0.11   6.11.0
     2.5.0      16.2.10   6.10.2
     2.4.12     16.1.10   6.10.1
     2.4.11     16.0.10   6.10.0
     2.4.10     15.0.9    6.9.0
     2.4.9	14.1.8    6.8.1
     2.4.8      14.0.8    6.8.0
     2.4.7      13.2.7    6.7.2
     2.4.6	13.1.7    6.7.1
     2.4.5      13.0.7    6.7.0
     2.4.4      12.2.6    6.6.2
     2.4.3      12.1.6    6.6.1
     2.4.2	12.0.6    6.6.0
     2.4.1      11.1.5    6.5.1
     2.4.0	11.0.5    6.5.0

As you can see the libtool number is derived from the so number. If the so number is a.b.c, the libtool number is a+b.c.b. It is somewhere in the libtool manual but I for one, never used that number. I used what they called the so numbers directly which is a bit more pleasant. I also don't see the point in using the libtool number in the .pc file instead of the version. As can be seen there is a one to one correspondence. And you shouldn't ever try to figure the so number from your .pc file, you are not supposed too.

I guess they are committed to the absurd scheme now.

[dimpase]

Branch: u/dimpase/packages/freetype_correct_version

[dimpase]

Author: Dima Pasechnik

[dimpase]

New commits:

5119f82	correct (sic) version for freetype 2.4 or better
168de8b	use macro for deps, unconditionally do AC_SUBSTs

[dimpase]

Commit: 168de8b

[mkoeppe]

Reviewer: Matthias Koeppe

[mkoeppe]

comment:5

These have been merged into 9.2.beta4