jekyll: 3.9.3
liquid: 4.0.4

Case: 'a/b/c'

size: 3
list: ["a","b","c"]
join: a/b/c

Case: '/a/b/c'

size: 4
list: ["","a","b","c"]
join: /a/b/c

Case: 'a/b/c/'

size: 3
list: ["a","b","c"]
join: a/b/c
split-join difference !!

Case: '/a/b/c/'

size: 4
list: ["","a","b","c"]
join: /a/b/c
split-join difference !!

Case: '/a/b/c/ '

size: 5
list: ["","a","b","c"," "]
join: /a/b/c/