diff options
| -rw-r--r-- | changelog.md | 1 | ||||
| -rw-r--r-- | lib/pure/collections/lists.nim | 2 | ||||
| -rw-r--r-- | tests/stdlib/tlists.nim | 13 |
3 files changed, 16 insertions, 0 deletions
diff --git a/changelog.md b/changelog.md index 1b97fd99a..d07f80623 100644 --- a/changelog.md +++ b/changelog.md @@ -22,6 +22,7 @@ - `macros.parseExpr` and `macros.parseStmt` now accept an optional filename argument for more informative errors. - Module `colors` expanded with missing colors from the CSS color standard. +- Fixed `lists.SinglyLinkedList` being broken after removing the last node ([#19353](https://github.com/nim-lang/Nim/pull/19353)). ## `std/smtp` diff --git a/lib/pure/collections/lists.nim b/lib/pure/collections/lists.nim index f7627ae67..d1de0ea67 100644 --- a/lib/pure/collections/lists.nim +++ b/lib/pure/collections/lists.nim @@ -739,6 +739,8 @@ proc remove*[T](L: var SinglyLinkedList[T], n: SinglyLinkedNode[T]): bool {.disc if prev.next == nil: return false prev.next = n.next + if L.tail == n: + L.tail = prev # update tail if we removed the last node true proc remove*[T](L: var DoublyLinkedList[T], n: DoublyLinkedNode[T]) = diff --git a/tests/stdlib/tlists.nim b/tests/stdlib/tlists.nim index 14cbf2f9d..00c5b1a27 100644 --- a/tests/stdlib/tlists.nim +++ b/tests/stdlib/tlists.nim @@ -258,5 +258,18 @@ template main = a.add(2) doAssert a.toSeq == @[1, 2] + block RemoveLastNodeFromSinglyLinkedList: + var list = initSinglyLinkedList[string]() + let n1 = newSinglyLinkedNode("sonic") + let n2 = newSinglyLinkedNode("the") + let n3 = newSinglyLinkedNode("tiger") + let n4 = newSinglyLinkedNode("hedgehog") + list.add(n1) + list.add(n2) + list.add(n3) + list.remove(n3) + list.add(n4) + doAssert list.toSeq == @["sonic", "the", "hedgehog"] + static: main() main() |