Density grid issue when buffer zone joins up around study region inlets

[LHMarshall]

Here is an example:

c1 <- data.frame(x = c(0,0,495,250,500,750,505,1000,1000,0),
                 y = c(0,500,500,250,100,250,500,500,0,0))
coords <- list(list(c1))
test.region <- make.region(coords = coords)
test.density <- make.density(test.region, x.space = 20, constant = 1)
plot(test.density, style = "blocks")
plot(test.region, add = T)

However, if we reduce the spacing of the density grid then the buffer will not join up.

test.density <- make.density(test.region, x.space = 2.5, constant = 1)
plot(test.density, style = "blocks")
plot(test.region, add = T)

The alternative would be to change the inlet into a gap.

Note this bug affects the density grid but not the results of the simulation unless the simulation warns that it cannot generate the requested population size.