From b17fedddc6122c9cf760428c963e57f175035fb1 Mon Sep 17 00:00:00 2001
From: Doctorwu <doctorwu@moego.pet>
Date: Sat, 6 Jan 2024 00:11:58 +0800
Subject: [PATCH 1/2] fix(runtime-core): fix empty fragment in runtime-core

fix #10007
---
 packages/runtime-core/src/renderer.ts | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/packages/runtime-core/src/renderer.ts b/packages/runtime-core/src/renderer.ts
index fa1f08c3c9c..50f8c75f030 100644
--- a/packages/runtime-core/src/renderer.ts
+++ b/packages/runtime-core/src/renderer.ts
@@ -1086,7 +1086,11 @@ function baseCreateRenderer(
       // since they are either generated by the compiler, or implicitly created
       // from arrays.
       mountChildren(
-        n2.children as VNodeArrayChildren,
+        // #10007
+        // such fragment like `<></>` will be compiled into
+        // a fragment which doesn't have a children.
+        // In this case fallback to an empty array
+        (n2.children || []) as VNodeArrayChildren,
         container,
         fragmentEndAnchor,
         parentComponent,

From a2e1d23ce81832d1b21313abc1c52644cc67e57b Mon Sep 17 00:00:00 2001
From: Doctorwu <doctorwu@moego.pet>
Date: Sat, 6 Jan 2024 00:39:07 +0800
Subject: [PATCH 2/2] fix(runtime-core): add test suit

---
 .../runtime-core/__tests__/rendererFragment.spec.ts  | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/packages/runtime-core/__tests__/rendererFragment.spec.ts b/packages/runtime-core/__tests__/rendererFragment.spec.ts
index a8299ef93df..5f1e869366f 100644
--- a/packages/runtime-core/__tests__/rendererFragment.spec.ts
+++ b/packages/runtime-core/__tests__/rendererFragment.spec.ts
@@ -351,4 +351,16 @@ describe('renderer: fragment', () => {
     render(renderFn(['two', 'one']), root)
     expect(serializeInner(root)).toBe(`text<div>two</div>text<div>one</div>`)
   })
+
+  // #10007
+  test('empty fragment', () => {
+    const root = nodeOps.createElement('div')
+
+    const renderFn = () => {
+      return openBlock(true), createBlock(Fragment, null)
+    }
+
+    render(renderFn(), root)
+    expect(serializeInner(root)).toBe('')
+  })
 })