From 04d3290e680e73051e835dd762e88cce51a9390c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kirill=20M=C3=BCller?= <kirill.mueller@ivt.baug.ethz.ch>
Date: Thu, 30 Jun 2016 16:44:06 +0200
Subject: [PATCH 1/2] don't check name in [[

---
 R/tbl-df.r                   | 3 ---
 tests/testthat/test-tbl-df.R | 6 +++---
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/R/tbl-df.r b/R/tbl-df.r
index 76121d000..583b91453 100644
--- a/R/tbl-df.r
+++ b/R/tbl-df.r
@@ -21,9 +21,6 @@ print.tbl_df <- function(x, ..., n = NULL, width = NULL) {
     colname <- i
   else
     colname <- j
-  if (is.character(colname) && length(colname) == 1L && !(colname %in% names(x))) {
-    stopc("Unknown column '", colname, "'")
-  }
   if (!exact) {
     warningc("exact ignored")
   }
diff --git a/tests/testthat/test-tbl-df.R b/tests/testthat/test-tbl-df.R
index 5416a78c0..8fcbafd9e 100644
--- a/tests/testthat/test-tbl-df.R
+++ b/tests/testthat/test-tbl-df.R
@@ -110,10 +110,10 @@ test_that("can use recursive indexing with [[", {
   expect_equal(foo[[c("x", "y")]], 1:3)
 })
 
-test_that("[[ throws error if name doesn't exist", {
+test_that("[[ returns NULL if name doesn't exist", {
   df <- data_frame(x = 1)
-  expect_error(df[["y"]], "Unknown column 'y'")
-  expect_error(df[[1, "y"]], "Unknown column 'y'")
+  expect_null(df[["y"]])
+  expect_null(df[[1, "y"]])
 })
 
 test_that("can use two-dimensional indexing with [[", {

From 4c3dca30d1db7e3102909babb6f7dd07f029ef01 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kirill=20M=C3=BCller?= <kirill.mueller@ivt.baug.ethz.ch>
Date: Thu, 30 Jun 2016 16:44:52 +0200
Subject: [PATCH 2/2] warn, and use exact = FALSE, for $

---
 R/tbl-df.r                   | 7 ++++---
 tests/testthat/test-tbl-df.R | 9 ++++++---
 2 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/R/tbl-df.r b/R/tbl-df.r
index 583b91453..510d49baf 100644
--- a/R/tbl-df.r
+++ b/R/tbl-df.r
@@ -31,10 +31,11 @@ print.tbl_df <- function(x, ..., n = NULL, width = NULL) {
 #' @export
 `$.tbl_df` <- function(x, i) {
   if (is.character(i) && !(i %in% names(x))) {
-    stopc("Unknown column '", i, "'")
+    warningc("Unknown column '", i, "'")
+    .subset2(x, i, exact = FALSE)
+  } else {
+    .subset2(x, i)
   }
-
-  .subset2(x, i)
 }
 
 #' @export
diff --git a/tests/testthat/test-tbl-df.R b/tests/testthat/test-tbl-df.R
index 8fcbafd9e..9babd405f 100644
--- a/tests/testthat/test-tbl-df.R
+++ b/tests/testthat/test-tbl-df.R
@@ -126,13 +126,16 @@ test_that("can use two-dimensional indexing with [[", {
 
 test_that("$ throws error if name doesn't exist", {
   df <- data_frame(x = 1)
-  expect_error(df$y, "Unknown column 'y'")
+  expect_warning(expect_null(df$y),
+                 "Unknown column 'y'")
 })
 
 test_that("$ doesn't do partial matching", {
   df <- data_frame(partial = 1)
-  expect_error(df$p, "Unknown column 'p'")
-  expect_error(df$part, "Unknown column 'part'")
+  expect_warning(expect_identical(df$p, 1),
+                 "Unknown column 'p'")
+  expect_warning(expect_identical(df$part, 1),
+                 "Unknown column 'part'")
   expect_error(df$partial, NA)
 })