From c126de8c2f8b893187e00383c76814ca9dd07ab8 Mon Sep 17 00:00:00 2001
From: Justin Starry <justin.starry@icloud.com>
Date: Sun, 18 Oct 2020 18:00:22 +0800
Subject: [PATCH] Fix call stack exceeded bug

---
 yew/src/html/mod.rs          |  8 ++++++++
 yew/src/virtual_dom/vcomp.rs | 25 +++++++++++++++++++++++--
 2 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/yew/src/html/mod.rs b/yew/src/html/mod.rs
index 481a0c4a18a..3f2d1901cd8 100644
--- a/yew/src/html/mod.rs
+++ b/yew/src/html/mod.rs
@@ -456,6 +456,14 @@ impl NodeRef {
         this.node = None;
         this.link = Some(node_ref);
     }
+
+    /// Reuse an existing `NodeRef`
+    pub(crate) fn reuse(&self, node_ref: Self) {
+        let mut this = self.0.borrow_mut();
+        let existing = node_ref.0.borrow();
+        this.node = existing.node.clone();
+        this.link = existing.link.clone();
+    }
 }
 
 /// Trait for building properties for a component
diff --git a/yew/src/virtual_dom/vcomp.rs b/yew/src/virtual_dom/vcomp.rs
index e9dcaa7d0a6..23b6d87854e 100644
--- a/yew/src/virtual_dom/vcomp.rs
+++ b/yew/src/virtual_dom/vcomp.rs
@@ -186,7 +186,7 @@ impl VDiff for VComp {
             if let VNode::VComp(ref mut vcomp) = &mut ancestor {
                 // If the ancestor is the same type, reuse it and update its properties
                 if self.type_id == vcomp.type_id && self.key == vcomp.key {
-                    self.node_ref.link(vcomp.node_ref.clone());
+                    self.node_ref.reuse(vcomp.node_ref.clone());
                     let scope = vcomp.scope.take().expect("VComp is not mounted");
                     mountable.reuse(scope.borrow(), next_sibling);
                     self.scope = Some(scope);
@@ -316,7 +316,7 @@ mod tests {
         }
 
         fn change(&mut self, _: Self::Properties) -> ShouldRender {
-            unimplemented!();
+            true
         }
 
         fn view(&self) -> Html {
@@ -324,6 +324,27 @@ mod tests {
         }
     }
 
+    #[test]
+    fn update_loop() {
+        let document = crate::utils::document();
+        let parent_scope: AnyScope = crate::html::Scope::<Comp>::new(None).into();
+        let parent_element = document.create_element("div").unwrap();
+
+        let mut ancestor = html! { <Comp></Comp> };
+        ancestor.apply(&parent_scope, &parent_element, NodeRef::default(), None);
+
+        for _ in 0..10000 {
+            let mut node = html! { <Comp></Comp> };
+            node.apply(
+                &parent_scope,
+                &parent_element,
+                NodeRef::default(),
+                Some(ancestor),
+            );
+            ancestor = node;
+        }
+    }
+
     #[test]
     fn set_properties_to_component() {
         html! {