fix(runtime-dom): "el._assign is not a function" in compat mode (#4121)

diff --git a/packages/runtime-dom/src/directives/vModel.ts b/packages/runtime-dom/src/directives/vModel.ts
index 6ca363a937cf08c880c9b70c42c97c8c2340c5cd..b3e10a2a1c2cd6994de4d0fca2e8da0b511a8111 100644 (file)
--- a/packages/runtime-dom/src/directives/vModel.ts
+++ b/packages/runtime-dom/src/directives/vModel.ts
@@ -18,7 +18,7 @@ import {
 type AssignerFn = (value: any) => void
 
 const getModelAssigner = (vnode: VNode): AssignerFn => {
-  const fn = vnode.props!['onUpdate:modelValue']
+  const fn = vnode.props!['onUpdate:modelValue'] || (__COMPAT__ && vnode.props!['onModelCompat:input'])
   return isArray(fn) ? value => invokeArrayFns(fn, value) : fn
 }