handle zarr at a domain without context (#119)

Co-authored-by: Mark Keller <[email protected]>

R/stores.R

@@ -439,7 +439,10 @@ HttpStore <- R6::R6Class("HttpStore",
 
       segments <- stringr::str_split(private$url, "/")[[1]]
       private$domain <- paste(segments[1:3], collapse="/")
-      private$base_path <- paste(segments[4:length(segments)], collapse="/")
+      # Support both cases in which the store is located at the root
+      # of the domain, or located under some base_path.
+      private$base_path <- ifelse(length(segments) == 3, "", 
+                                  paste(segments[4:length(segments)], collapse="/"))
 
       if(!requireNamespace("crul", quietly = TRUE)) {
         stop("HttpStore requires the crul package")