upcoming sf breaks tmaptools (when adopting s2)

[edzer]

Please see https://github.com/mtennekes/tmap/issues/564 and r-spatial/sf#1649 and consider commenting on the latter in case things are not trivial. @paleolimbot wold map with topology failure on S2:

Running examples in ‘tmaptools-Ex.R’ failed
The error most likely occurred in:

> base::assign(".ptime", proc.time(), pos = "CheckExEnv")
> ### Name: crop_shape
> ### Title: Crop shape object
> ### Aliases: crop_shape
>
> ### ** Examples
>
> if (require(tmap) && packageVersion("tmap") >= "2.0") {
+     data(World, NLD_muni, land, metro)
+
+     #land_NLD <- crop_shape(land, NLD_muni)
+
+     #qtm(land_NLD, raster="trees", style="natural")
+
+     metro_Europe <- crop_shape(metro, World[World$continent == "Europe", ], polygon = TRUE)
+
+     qtm(World) +
+     tm_shape(metro_Europe) +
+       tm_bubbles("pop2010", col="red", title.size="European cities") +
+       tm_legend(frame=TRUE)
+ }
Loading required package: tmap
Error in s2_geography_from_wkb(x, oriented = oriented, check = check) :
  Loop 5 edge 0 crosses loop 6 edge 4
Calls: crop_shape ... as_s2_geography.WKB -> new_s2_xptr -> s2_geography_from_wkb
Execution halted