Fix edge case with nested choices. Fixes rstudio#560

When the set of choices is a list containing a named vector of length 1,
choicesWithNames would return the wrong result.

Author: wch

R/bootstrap.R

@@ -681,7 +681,7 @@ choicesWithNames <- function(choices) {
     res <- lapply(obj, function(val) {
       if (is.list(val))
         listify(val)
-      else if (length(val) == 1)
+      else if (length(val) == 1 && is.null(names(val)))
         val
       else
         makeNamed(as.list(val))

inst/tests/test-bootstrap.r

@@ -76,6 +76,11 @@ test_that("Choices are correctly assigned names", {
     choicesWithNames(list(A="a", B="b", C=list("d", "e"))),
     list(A="a", B="b", C=list(d="d", e="e"))
   )
+  # List, named, with a named sub-vector of length 1
+  expect_identical(
+    choicesWithNames(list(A="a", B="b", C=c(D="d"))),
+    list(A="a", B="b", C=list(D="d"))
+  )
   # List, some named, with sublist
   expect_identical(
     choicesWithNames(list(A="a", "b", C=list("d", E="e"))),