fix(reactivity): fix shallow/readonly edge cases

packages/reactivity/src/baseHandlers.ts

@@ -158,10 +158,10 @@ function createSetter(shallow = false) {
     if (isReadonly(oldValue) && isRef(oldValue) && !isRef(value)) {
       return false
     }
-    if (!shallow && !isReadonly(value)) {
-      if (!isShallow(value)) {
-        value = toRaw(value)
+    if (!shallow) {
+      if (!isShallow(value) && !isReadonly(value)) {
         oldValue = toRaw(oldValue)
+        value = toRaw(value)
       }
       if (!isArray(target) && isRef(oldValue) && !isRef(value)) {
         oldValue.value = value

packages/reactivity/src/ref.ts

@@ -6,7 +6,14 @@ import {
 } from './effect'
 import { TrackOpTypes, TriggerOpTypes } from './operations'
 import { isArray, hasChanged, IfAny } from '@vue/shared'
-import { isProxy, toRaw, isReactive, toReactive } from './reactive'
+import {
+  isProxy,
+  toRaw,
+  isReactive,
+  toReactive,
+  isReadonly,
+  isShallow
+} from './reactive'
 import type { ShallowReactiveMarker } from './reactive'
 import { CollectionTypes } from './collectionHandlers'
 import { createDep, Dep } from './dep'
@@ -112,10 +119,12 @@ class RefImpl<T> {
   }
 
   set value(newVal) {
-    newVal = this.__v_isShallow ? newVal : toRaw(newVal)
+    const useDirectValue =
+      this.__v_isShallow || isShallow(newVal) || isReadonly(newVal)
+    newVal = useDirectValue ? newVal : toRaw(newVal)
     if (hasChanged(newVal, this._rawValue)) {
       this._rawValue = newVal
-      this._value = this.__v_isShallow ? newVal : toReactive(newVal)
+      this._value = useDirectValue ? newVal : toReactive(newVal)
       triggerRefValue(this, newVal)
     }
   }