fix: avoid chromium issue with dispatching blur on element removal (#13694)

* fix: avoid chromium issue with dispatching blur on element removal

* fix: avoid chromium issue with dispatching blur on element removal

* fix: avoid chromium issue with dispatching blur on element removal

* active effect too

* try/finally

Author: trueadm

.changeset/seven-dancers-brush.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: avoid chromium issue with dispatching blur on element removal

packages/svelte/src/internal/client/reactivity/effects.js

@@ -16,7 +16,8 @@ import {
 	set_is_destroying_effect,
 	set_is_flushing_effect,
 	set_signal_status,
-	untrack
+	untrack,
+	set_active_effect
 } from '../runtime.js';
 import {
 	DIRTY,
@@ -375,13 +376,26 @@ export function destroy_effect(effect, remove_dom = true) {
 		/** @type {TemplateNode | null} */
 		var node = effect.nodes_start;
 		var end = effect.nodes_end;
+		var previous_reaction = active_reaction;
+		var previous_effect = active_effect;
 
-		while (node !== null) {
-			/** @type {TemplateNode | null} */
-			var next = node === end ? null : /** @type {TemplateNode} */ (get_next_sibling(node));
+		// Really we only need to do this in Chromium because of https://chromestatus.com/feature/5128696823545856,
+		// as removal of the DOM can cause sync `blur` events to fire, which can cause logic to run inside
+		// the current `active_reaction`, which isn't what we want at all. Additionally, the blur event handler
+		// might create a derived or effect and they will be incorrectly attached to the wrong thing
+		set_active_reaction(null);
+		set_active_effect(null);
+		try {
+			while (node !== null) {
+				/** @type {TemplateNode | null} */
+				var next = node === end ? null : /** @type {TemplateNode} */ (get_next_sibling(node));
 
-			node.remove();
-			node = next;
+				node.remove();
+				node = next;
+			}
+		} finally {
+			set_active_reaction(previous_reaction);
+			set_active_effect(previous_effect);
 		}
 
 		removed = true;