Fix coord_radial() full circle bug

NEWS.md

@@ -12,6 +12,8 @@
 * Patterns and gradients are now also enabled in `geom_sf()` 
   (@teunbrand, #5716).
 * `stat_bin()` deals with non-finite breaks better (@teunbrand, #5665).
+* Fixed bug in `coord_radial()` where full circles were not treated as such 
+  (@teunbrand, #5750).
 * When legends detect the presence of values in a layer, `NA` is now detected
   if the data contains values outside the given breaks (@teunbrand, #5749).
 * `annotate()` now warns about `stat` or `position` arguments (@teunbrand, #5151)

R/coord-radial.R

@@ -512,6 +512,11 @@ polar_bbox <- function(arc, margin = c(0.05, 0.05, 0.05, 0.05),
 # For any `theta` in [0, 2 * pi), test if theta is inside the span
 # given by `arc`
 in_arc <- function(theta, arc) {
+  # Full circle case
+  if (abs(diff(arc)) > 2 * pi - sqrt(.Machine$double.eps)) {
+    return(rep(TRUE, length(theta)))
+  }
+  # Partial circle case
   arc <- arc %% (2 * pi)
   if (arc[1] < arc[2]) {
     theta >= arc[1] & theta <= arc[2]

tests/testthat/test-coord-polar.R

@@ -124,6 +124,12 @@ test_that("bounding box calculations are sensible", {
     list(x = c(0, 1), y = c(0, 1))
   )
 
+  # Full offset cirle
+  expect_equal(
+    polar_bbox(arc = c(2 * pi, 4 * pi)),
+    list(x = c(0, 1), y = c(0, 1))
+  )
+
   # Right half of circle
   expect_equal(
     polar_bbox(arc = c(0, pi)),