From 8d11625f16f288f0c10c6928bd98039b07c9e42d Mon Sep 17 00:00:00 2001
From: Jan Marvin Garbuszus <jan.garbuszus@ruhr-uni-bochum.de>
Date: Thu, 17 Aug 2023 18:31:41 +0200
Subject: [PATCH] guard against empty cc cases

---
 R/read.R                           |  5 +++++
 tests/testthat/test-wb_functions.R | 11 +++++++++++
 2 files changed, 16 insertions(+)

diff --git a/R/read.R b/R/read.R
index 7717c07fa..9693f1d17 100644
--- a/R/read.R
+++ b/R/read.R
@@ -312,6 +312,11 @@ wb_to_df <- function(
   if (!is.null(cols) && !is.null(rows) && !missing(dims))
     cc <- cc[cc$row_r %in% keep_rows & cc$c_r %in% keep_cols, ]
 
+  # guard against special case where no col/row is part of cc
+  if (NROW(cc) == 0) {
+    cc[1, ] <- rep("", ncol(cc))
+  }
+
   cc$val <- NA_character_
   cc$typ <- NA_character_
 
diff --git a/tests/testthat/test-wb_functions.R b/tests/testthat/test-wb_functions.R
index d717e03a3..c4352d96f 100644
--- a/tests/testthat/test-wb_functions.R
+++ b/tests/testthat/test-wb_functions.R
@@ -304,3 +304,14 @@ test_that("cols return order is correct", {
   expect_equal(exp, got)
 
 })
+
+test_that("missings cells are returned", {
+
+  wb <- wb_workbook()$add_worksheet()$add_data(x = "a", dims = "Z100")
+
+  expect_silent(got <- wb_to_df(wb, col_names = FALSE, rows = 1, cols = 1))
+  expect_silent(got <- wb_to_df(wb, col_names = FALSE, rows = c(1, 4, 10), cols = c(2, 5, 10)))
+
+  expect_silent(got <- wb_to_df(wb, col_names = FALSE, rows = c(101), cols = c(27)))
+
+})