fix: Recycling of logical vectors when indexing into edge/vertex sele…

…ctors now throws an error (#1731)

R/iterators.R

@@ -676,6 +676,10 @@ simple_vs_index <- function(x, i, na_ok = FALSE) {
       if (is.null(ii)) {
         return(NULL)
       }
+      if (is.logical(ii) && (length(ii) != length(x) && length(ii) != 1)) {
+        cli::cli_abort("Error: Logical index length does not match the number of vertices. Recycling is not allowed.")
+      }
+
       ii <- simple_vs_index(x, ii, na_ok)
       attr(ii, "env") <- attr(x, "env")
       attr(ii, "graph") <- attr(x, "graph")
@@ -991,6 +995,10 @@ simple_es_index <- function(x, i, na_ok = FALSE) {
       if (is.null(ii)) {
         return(NULL)
       }
+      if (is.logical(ii) && (length(ii) != length(x) && length(ii) != 1)) {
+        cli::cli_abort("Error: Logical index length does not match the number of edges. Recycling is not allowed.")
+      }
+
       ii <- simple_es_index(x, ii)
       attr(ii, "env") <- attr(x, "env")
       attr(ii, "graph") <- attr(x, "graph")

tests/testthat/_snaps/iterators.md

@@ -92,3 +92,19 @@
       + 10/? edges (deleted) (vertex names):
        [1] a|b b|c c|d d|e e|f f|g g|h h|i i|j a|j
 
+# logical indices are not recycled
+
+    Code
+      V(g)[c(TRUE, FALSE)]
+    Condition
+      Error in `FUN()`:
+      ! Error: Logical index length does not match the number of vertices. Recycling is not allowed.
+
+---
+
+    Code
+      E(g)[c(TRUE, FALSE)]
+    Condition
+      Error in `FUN()`:
+      ! Error: Logical index length does not match the number of edges. Recycling is not allowed.
+

tests/testthat/test-iterators.R

@@ -440,3 +440,10 @@ test_that("edge indexes are stored as raw numbers", {
   expect_identical(E(g)$id, as.numeric(1:3))
   expect_error(induced_subgraph(g, 1:2), NA)
 })
+
+test_that("logical indices are not recycled", {
+  # https://github.com/igraph/rigraph/issues/848
+  g <- make_ring(5)
+  expect_snapshot(V(g)[c(TRUE, FALSE)], error = TRUE)
+  expect_snapshot(E(g)[c(TRUE, FALSE)], error = TRUE)
+})