- Caveats: S1 should not begin with `/', unless S2 also begins with
- '/'. S1 should not contain things like ".." and such --
- construct_relative ("fly/ioccc/../index.html",
- "fly/images/fly.gif") will fail. (A workaround is to call
- something like path_simplify() on S1). */
+ cr("foo", "bar") -> "bar"
+ cr("A/foo", "A/bar") -> "bar"
+ cr("A/foo", "A/B/bar") -> "B/bar"
+ cr("A/X/foo", "A/Y/bar") -> "../Y/bar"
+ cr("X/", "Y/bar") -> "../Y/bar" (trailing slash does matter in BASE)
+
+ Both files should be absolute or relative, otherwise strange
+ results might ensue. The function makes no special efforts to
+ handle "." and ".." in links, so make sure they're not there
+ (e.g. using path_simplify). */