revert pr for position_dodge2 (#4945)

Author: javlon

R/position-dodge2.r

@@ -138,7 +138,7 @@ find_x_overlaps <- function(df) {
   overlaps[1] <- counter <- 1
 
   for (i in seq_asc(2, nrow(df))) {
-    if (is.na(df$xmin[i]) || is.na(df$xmax[i - 1]) || df$xmin[i] > df$xmax[i - 1]) {
+    if (is.na(df$xmin[i]) || is.na(df$xmax[i - 1]) || df$xmin[i] >= df$xmax[i - 1]) {
       counter <- counter + 1
     }
     overlaps[i] <- counter

tests/testthat/test-position-dodge2.R

@@ -110,3 +110,11 @@ test_that("NA values are given their own group", {
   )
   expect_equal(find_x_overlaps(df), seq_len(4))
 })
+
+test_that("groups are different when two blocks have externall touching point",{
+  df1 <- data.frame(
+    xmin = c(0.5, 1.5),
+    xmax = c(1.5, 2.5)
+  )
+  expect_equal(find_x_overlaps(df1), seq_len(2))
+})