From c59897c7b0dbd82b5bbf3fbca945c0639ac37fb8 Mon Sep 17 00:00:00 2001
From: edison <daiwei521@126.com>
Date: Fri, 4 Dec 2020 01:17:04 +0800
Subject: [PATCH] fix(runtime-core): skip patchBlockChildren if
 n1.dynamicChildren is null (#2717)

fix #2715

The bug was introduced by #2485 where a compiled slot may result in a bailed Fragment
which then gets its dynamicChildren set to `null` by the renderer.
---
 packages/runtime-core/src/renderer.ts | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/packages/runtime-core/src/renderer.ts b/packages/runtime-core/src/renderer.ts
index 646631507d4..3baaf2405ea 100644
--- a/packages/runtime-core/src/renderer.ts
+++ b/packages/runtime-core/src/renderer.ts
@@ -1139,12 +1139,15 @@ function baseCreateRenderer(
       if (
         patchFlag > 0 &&
         patchFlag & PatchFlags.STABLE_FRAGMENT &&
-        dynamicChildren
+        dynamicChildren &&
+        // #2715 the previous fragment could've been a BAILed one as a result
+        // of renderSlot() with no valid children
+        n1.dynamicChildren
       ) {
         // a stable fragment (template root or <template v-for>) doesn't need to
         // patch children order, but it may contain dynamicChildren.
         patchBlockChildren(
-          n1.dynamicChildren!,
+          n1.dynamicChildren,
           dynamicChildren,
           container,
           parentComponent,