JSA tile regions at the corners of the split facet overlap many others

[grahambell]

For the two tiles at the north and south corners of the facet at RA=12h which is split between the lower left and upper right corners of the FITS HPX projection plane (in the nested scheme with Nside=64 these are tiles 24576 and 28671), if the region output by TILEINFO is given to TILELIST it matches many tiles. This is shown in the picture below by the red speckly area (it's not solid as I only plotted intermittent tiles in there for plotting speed). Tile 24576 is marked by the large green dot.

To reproduce the problem:

$ tileinfo instrument="SCUBA-2(850)" itile=24576 region=region.ast
$ tilelist instrument="SCUBA-2(850)" region=region.ast

From the picture above it looks like the extra tiles are matching because the uncertainty is just over 2 facets wide. Inserting these lines into smf_jsatiles_region before the KeyMap loop makes the problem go away:

double circle_centre[] = {0, 0};
double circle_point[] = {0};
astSetUnc(region, astCircle(fs, 1, circle_centre, circle_point, NULL, ""));

But that probably isn't the proper solution.

[dsberry]

Fixed by commit abfacf01495dcaad3b3b03ad0fd4c1a28e3835be