fix #6093, inject should not be merged with Object.create

src/core/util/options.js

@@ -195,7 +195,6 @@ strats.watch = function (parentVal: ?Object, childVal: ?Object): ?Object {
  */
 strats.props =
 strats.methods =
-strats.inject =
 strats.computed = function (parentVal: ?Object, childVal: ?Object): ?Object {
   if (!childVal) return Object.create(parentVal || null)
   if (!parentVal) return childVal
@@ -204,6 +203,12 @@ strats.computed = function (parentVal: ?Object, childVal: ?Object): ?Object {
   extend(ret, childVal)
   return ret
 }
+strats.inject = function (parentVal: ?Object, childVal: ?Object): ?Object {
+  const ret = {}
+  extend(ret, parentVal)
+  extend(ret, childVal)
+  return ret
+}
 strats.provide = mergeDataOrFn
 
 /**

test/unit/features/options/inject.spec.js

@@ -442,4 +442,25 @@ describe('Options provide/inject', () => {
     expect(isObserver(child.bar)).toBe(false)
     expect(isObserver(child.baz)).toBe(false)
   })
+
+  // #6093
+  it('should merge inject from mixins properly', () => {
+    const mixinA = { inject: ['foo'] }
+    const mixinB = { inject: ['bar'] }
+    const child = {
+      template: `<span/>`,
+      mixins: [mixinA, mixinB],
+      created () {
+        injected = [this.foo, this.bar]
+      }
+    }
+    new Vue({
+      provide: { foo: 'foo', bar: 'bar' },
+      render (h) {
+        return h(child)
+      }
+    }).$mount()
+
+    expect(injected).toEqual(['foo', 'bar'])
+  })
 })