spkg-configure.m4 for planarity

[dimpase]

this is a relatively stable C library, the only problem is that there are also very old versions (2.2.0 on Fedora 26) around, and it's not quite clear whether they work and how to distinguish them.

We do the latter by checking for link member in vertexRec from planarity/graphStructures.h

CC: @kiwifb @embray @tobihan @infinity0 @isuruf @mkoeppe

Component: build: configure

Author: Dima Pasechnik

Branch/Commit: 604dfac

Reviewer: Isuru Fernando

Issue created by migration from https://trac.sagemath.org/ticket/29063

[dimpase]

comment:1

package names:

planarity libplanarity-dev (Debian)

planarity planarity-devel (Fedora)

[dimpase]

Author: Dima Pasechnik

[dimpase]

comment:2

2.2.0 prevents sagelib building, as planarity/graphStructures.h should have

typedef struct
{
        int  link[2];
        int  index;
        unsigned flags;
} vertexRec;

and not

typedef struct
{
        int DFSParent, leastAncestor, Lowpoint, adjacentTo;
        int pertinentBicompList, separatedDFSChildList, fwdArcList;
} vertexRec;

So we can write a test using AC_COMPILE_IFELSE().

[dimpase]

Branch: u/dimpase/packages/planarity-config

[dimpase]

Commit: 604dfac

[dimpase]

New commits:

604dfac

spkg-configure.m4 for planarity

[isuruf]

Reviewer: Isuru Fernando

[vbraun]

Changed branch from u/dimpase/packages/planarity-config to 604dfac