fix(compiler): adjust children generation order for hydration

Copied from https://github.com/vuejs/core/pull/13729/files

Author: zhiyuanzmj

packages/compiler/src/generators/block.ts

@@ -65,7 +65,9 @@ export function genBlockContent(
     push(...genSelf(child, context))
   }
   for (const child of dynamic.children) {
-    push(...genChildren(child, context, push, `n${child.id!}`))
+    if (!child.hasDynamicChild) {
+      push(...genChildren(child, context, push, `n${child.id!}`))
+    }
   }
 
   push(...genOperations(operation, context))

packages/compiler/src/generators/template.ts

@@ -23,7 +23,7 @@ export function genSelf(
   context: CodegenContext,
 ): CodeFragment[] {
   const [frag, push] = buildCodeFragment()
-  const { id, template, operation } = dynamic
+  const { id, template, operation, hasDynamicChild } = dynamic
 
   if (id !== undefined && template !== undefined) {
     push(NEWLINE, `const n${id} = t${template}()`)
@@ -34,6 +34,10 @@ export function genSelf(
     push(...genOperationWithInsertionState(operation, context))
   }
 
+  if (hasDynamicChild) {
+    push(...genChildren(dynamic, context, push, `n${id}`))
+  }
+
   return frag
 }
 
@@ -49,7 +53,6 @@ export function genChildren(
 
   let offset = 0
   let prev: [variable: string, elementIndex: number] | undefined
-  const childrenToGen: [IRDynamicInfo, string][] = []
 
   for (const [index, child] of children.entries()) {
     if (child.flags & DynamicFlag.NON_TEMPLATE) {
@@ -93,7 +96,7 @@ export function genChildren(
       pushBlock(...init)
     }
 
-    if (id === child.anchor) {
+    if (id === child.anchor && !child.hasDynamicChild) {
       push(...genSelf(child, context))
     }
 
@@ -102,13 +105,7 @@ export function genChildren(
     }
 
     prev = [variable, elementIndex]
-    childrenToGen.push([child, variable])
-  }
-
-  if (childrenToGen.length) {
-    for (const [child, from] of childrenToGen) {
-      push(...genChildren(child, context, pushBlock, from))
-    }
+    push(...genChildren(child, context, pushBlock, variable))
   }
 
   return frag

packages/compiler/test/transforms/__snapshots__/transformChildren.spec.ts.snap

@@ -23,10 +23,10 @@ exports[`compiler: children transform > efficient traversal 1`] = `
 "
   const n3 = t0()
   const p0 = _next(_child(n3))
-  const p1 = _next(p0)
-  const p2 = _next(p1)
   const n0 = _child(p0)
+  const p1 = _next(p0)
   const n1 = _child(p1)
+  const p2 = _next(p1)
   const n2 = _child(p2)
   const x0 = _child(n0)
   _setNodes(x0, () => ({ msg: msg }))