fix(runtime-core): avoid mutating EMPTY_ARR when setting dev root (#2419)

also freeze EMPTY_ARR in dev

fix #2413

packages/runtime-core/src/componentProps.ts

@@ -378,7 +378,7 @@ export function normalizePropsOptions(
   }
 
   if (!raw && !hasExtends) {
-    return (comp.__props = EMPTY_ARR)
+    return (comp.__props = EMPTY_ARR as any)
   }
 
   if (isArray(raw)) {

packages/runtime-core/src/componentRenderUtils.ts

@@ -226,7 +226,7 @@ const getChildRoot = (
     return [vnode, undefined]
   }
   const rawChildren = vnode.children as VNodeArrayChildren
-  const dynamicChildren = vnode.dynamicChildren as VNodeArrayChildren
+  const dynamicChildren = vnode.dynamicChildren
   const childRoot = filterSingleRoot(rawChildren)
   if (!childRoot) {
     return [vnode, undefined]
@@ -235,10 +235,12 @@ const getChildRoot = (
   const dynamicIndex = dynamicChildren ? dynamicChildren.indexOf(childRoot) : -1
   const setRoot = (updatedRoot: VNode) => {
     rawChildren[index] = updatedRoot
-    if (dynamicIndex > -1) {
-      dynamicChildren[dynamicIndex] = updatedRoot
-    } else if (dynamicChildren && updatedRoot.patchFlag > 0) {
-      dynamicChildren.push(updatedRoot)
+    if (dynamicChildren) {
+      if (dynamicIndex > -1) {
+        dynamicChildren[dynamicIndex] = updatedRoot
+      } else if (updatedRoot.patchFlag > 0) {
+        vnode.dynamicChildren = [...dynamicChildren, updatedRoot]
+      }
     }
   }
   return [normalizeVNode(childRoot), setRoot]

packages/runtime-core/src/vnode.ts

@@ -243,7 +243,7 @@ export function createBlock(
     true /* isBlock: prevent a block from tracking itself */
   )
   // save current block children on the block vnode
-  vnode.dynamicChildren = currentBlock || EMPTY_ARR
+  vnode.dynamicChildren = currentBlock || (EMPTY_ARR as any)
   // close block
   closeBlock()
   // a block is always going to be patched, so track it as a child of its