Fix for legacy recipes in bake.step_log() method

- legacy recipes index the `columns` entry of `object`
  whereas newer recipes index `names(object$columns)`
- this breaks backward compatibility
- This bugfix prefers the 'new' syntax, but if
  `names(object)` is `NULL`, reverts to the 'old' syntax
- fixes tidymodels#1284

NEWS.md

@@ -24,6 +24,8 @@
 
 ## Bug Fixes
 
+* Fixed bug where `step_log()` breaks legacy recipe objects by indexing `names(object)` in `bake()`. (@stufield, #1284)
+
 * Fixed bug where `step_factor2string()` if `strings_as_factors = TRUE` is set in `prep()`. (#317)
 
 * Fixed bug where `tidy.step_cut()` always returned zero row tibbles for trained recipes. (#1229)

R/log.R

@@ -124,7 +124,7 @@ prep.step_log <- function(x, training, info = NULL, ...) {
 
 #' @export
 bake.step_log <- function(object, new_data, ...) {
-  col_names <- names(object$columns)
+  col_names <- names(object$columns) %||% object$columns
   check_new_data(col_names, object, new_data)
 
   # for backward compat