Merge branch 'master' of github.com:hadley/dplyr

Author: hadley

NEWS.md

@@ -158,6 +158,8 @@
   missing values (#774). `row_number()` doesn't segfault when giving an external
   variable with the wrong number of variables (#781) 
 
+* `group_indices` handles the edge case when there are no variables (#867)  
+  
 # dplyr 0.3.0.1
 
 * Fixed problem with test script on Windows.

R/funs.R

@@ -1,7 +1,7 @@
 #' Create a list of functions calls.
 #'
-#' \code{funs} provides a flexible to generate a named list of functions for
-#' input to other functions like \code{colwise}.
+#' \code{funs} provides a flexible way to generate a named list of functions for
+#' input to other functions like \code{summarise_each}.
 #'
 #' @param dots,... A list of functions specified by:
 #'

src/group_indices.cpp

@@ -22,6 +22,8 @@ IntegerVector grouped_indices_grouped_df_impl( GroupedDataFrame gdf ){
 // [[Rcpp::export]]
 IntegerVector grouped_indices_impl( DataFrame data, ListOf<Symbol> symbols ){
     int nsymbols = symbols.size() ;
+    if( nsymbols == 0 ) 
+        return rep(1, data.nrows()) ;
     CharacterVector vars(nsymbols) ;
     for( int i=0; i<nsymbols; i++){
         vars[i] = PRINTNAME(symbols[i]) ;

tests/testthat/test-group-indices.R

@@ -6,3 +6,14 @@ test_that("group_indices from ungrouped or grouped gives same result", {
   expect_equal(res1, res2)  
 })
 
+test_that("group_indices handles the case where no variable is given (#867)", {
+  res <- group_indices(mtcars)
+  expect_true( all(res==1L) )
+})
+
+test_that("group_indices handles grouped data and no arguments", {
+  res1 <- mtcars %>% group_by(cyl) %>% group_indices()
+  res2 <- mtcars %>% group_indices(cyl)
+  expect_equal(res1, res2) 
+})
+