mapcache_detail extent fix

[geographika]

Building and running the latest mapcache from source on Linux (with 3.12.1t64) and running the following command:

mapcache_detail --config /etc/mapcache/mapcache.xml \
    --tileset RoadsNetworkFull \
    --grid GoogleMapsCompatible \
    --extent -959158.2616546892,6776636.979084599,-958505.4972916227,6777878.296881017

Would always result in the following error:

mapcache_detail: Requested geometry is not contained within Grid extent: [ -20037508.3427892476, -20037508.3427892476, 20037508.3427892476, 20037508.3427892476 ]

It seems any extent with a negative value would return this error (even when clearly within the grid).

Strangely, the same command and cache with a Windows build (but with GEOS 3.10.6) would run without any issue.

From trial and error I got the fix below, and the command now runs on Linux also. It seems as though GEOSGeom_createLinearRing requires a fully populated coordinate sequence or it returns an invalid polygon which never overlaps?

@jbo-ads - any insight on the above? And thanks for mapcache_detail - looks a useful tool.

[geographika]

Possibly related #307

[jbo-ads]

Indeed, seeing your fix, I wonder how it worked at all before.