use vapply instead of sapply

Author: ThierryO

src/library/tools/R/license.R

@@ -614,7 +614,12 @@ function(x)
                                stringsAsFactors = FALSE)
         }
 
-        sapply(expansions, `[[`, "SPDX") |>
+        vapply(
+            expansions, FUN.VALUE = character(1),
+            FUN = function(z) {
+                paste(z[["SPDX"]], collapse = " OR ")
+            }
+        ) |>
             paste(collapse = " OR ") -> spdx
         ## Replace expansions by their labels from the license db.
         ## (As these are unique, we can always easily get the full