Rerender fails when rendering an iterable with None elements inside

[ochrons]

Problem

When rendering a list of components again with a different list, where the first list contains some None (ie. empty nodes), there is a panic:

panicked at /home/ochrons/.cargo/registry/src/index.crates.io-6f17d22bba15001f/dioxus-core-0.5.1/src/diff/node.rs:142:49:
called `Option::unwrap()` on a `None` value

$core::option::unwrap_failed::hb5bacfb0dd292085    @    Zhef_bg.wasm:0x513587
$dioxus_core::diff::node::<impl dioxus_core::nodes::VNode>::find_last_element::h2fbafeb25fa6485a    @    Zhef_bg.wasm:0x24a677
$dioxus_core::diff::iterator::<impl dioxus_core::virtual_dom::VirtualDom>::create_and_insert_after::hdf1b487b5c58bd2e    @    Zhef_bg.wasm:0x48288f
$dioxus_core::diff::iterator::<impl dioxus_core::virtual_dom::VirtualDom>::diff_non_keyed_children::h825ddb6722191889    @    Zhef_bg.wasm:0x236220
$dioxus_core::diff::iterator::<impl dioxus_core::virtual_dom::VirtualDom>::diff_non_empty_fragment::h9f386364ef278952    @    Zhef_bg.wasm:0x2588a3
$dioxus_core::diff::node::<impl dioxus_core::nodes::VNode>::diff_dynamic_node::hccca532b469dca0c    @    Zhef_bg.wasm:0x19bbcf
$dioxus_core::diff::node::<impl dioxus_core::nodes::VNode>::diff_node::{{closure}}::he12ecb157d0a2bc4    @    Zhef_bg.wasm:0x4e38

I'm rendering a li with changing number of children

let description: impl Iterator<Item = Option<VNode>>
...
rsx! {
    li { {description} }
}

some of the items in the iterator are None. The generated HTML looks like

<li data-node-hydration="103"><!--node-id104-->Shape <!--#--><!--node-id105--> into <!--#--></li>

if I replace the empty nodes with some valid rsx (empty string), this problem doesn't occur and then the HTML looks like

<li data-node-hydration="118">
<!--node-id119-->Shape <!--#--><!--node-id120--><!--node-id121--> into <!--#--><!--node-id122--><!--node-id123--><!--#-->
</li>

Expected behavior

Shouldn't panic, but render the new list of items correctly.

Screenshots

If applicable, add screenshots to help explain your problem.

Environment:

• Dioxus version: 0.5.1
• Rust version: 1.78
• OS info: Win11 WSL2
• App platform: fullstack

[ealmloff]

Reproduction with the latest version of dioxus main:

use dioxus::prelude::*;

fn main() {
    launch(app);
}

fn app() -> Element {
    let mut count = use_signal(|| 0);

    let items = (0..count()).map(|_| {
        if count() % 2 == 0 {
            VNode::empty()
        } else {
            rsx! {
                li {
                    "Fizz"
                }
            }
        }
    });

    rsx! {
        h1 { "High-Five counter: {count}" }
        button { onclick: move |_| count += 1, "Up high!" }
        button { onclick: move |_| count -= 1, "Down low!" }
        ul {
            {items}
        }
    }
}