fix

Author: MichaelChirico

R/as.data.table.R

@@ -147,7 +147,7 @@ as.data.table.list = function(x,
     if (check_rownames && is.null(rownames_)) {
       if (is.null(dim(xi))) {
         if (!is.null(nm <- names(xi)) && any(nzchar(nm))) {
-          rn = nm
+          rownames_ = nm
           x[[i]] = unname(xi)
         }
       } else {
@@ -224,15 +224,12 @@ as.data.table.list = function(x,
   # Add rownames column when vector names were found
   if (!is.null(rownames_)) {
     rn_name = if (is.character(keep.rownames)) keep.rownames[1L] else "rn"
-    ans = c(list(recycle(rownames_, nrow)), ans)
-    vnames = c(rn_name, vnames)
-  } else if (check_rownames) {
-    # case like data.table(a = 1, data.frame(b = 2, row.names='c')) where expanding the inner DF picks up the row names --
-    #   we want to bump the resulting column to the front of the output
-    rn_name = if (is.character(keep.rownames)) keep.rownames[1L] else "rn"
-    if (!is.na(idx <- chmatch(rn_name, names(ans))[1L]) && idx != 1L) {
-      ans = c(ans[[idx]], ans[-idx])
+    if (!is.na(idx <- chmatch(rn_name, vnames)[1L])) {
+      ans = c(list(ans[[idx]]), ans[-idx])
       vnames = c(vnames[idx], vnames[-idx])
+    } else {
+      ans = c(list(recycle(rownames_, nrow)), ans)
+      vnames = c(rn_name, vnames)
     }
   }
   setattr(ans, "names", vnames)

inst/tests/tests.Rraw

@@ -21424,4 +21424,4 @@ b <- setNames(c(10, 11, 12), c("", "B", ""))
 test(2330.7, as.data.table(list(b), keep.rownames=TRUE), data.table(rn=c("", "B", ""), V1=c(10, 11, 12)))
 
 DF <- data.frame(row.names = letters[1:6], V = 1:6)     # Test data.frame with explicit rownames
-test(2330.8, as.data.table(list(a = 6:1, DF), keep.rownames=TRUE), data.table(rn=c("a", "b", "c", "d", "e", "f"), a=c(6, 5, 4, 3, 2, 1), V=1:6))
+test(2330.8, as.data.table(list(a = 6:1, DF), keep.rownames=TRUE), data.table(rn=c("a", "b", "c", "d", "e", "f"), a=6:1, V=1:6))