fix(runtime-core): unable to set object to dom props

- Remove casting nullish values to ''

packages/runtime-dom/__tests__/patchProps.spec.ts

@@ -7,7 +7,7 @@ describe('runtime-dom: props patching', () => {
     patchProp(el, 'id', null, 'foo')
     expect(el.id).toBe('foo')
     patchProp(el, 'id', null, null)
-    expect(el.id).toBe('')
+    expect(el.id).toBe('null')
   })
 
   test('value', () => {
@@ -30,6 +30,16 @@ describe('runtime-dom: props patching', () => {
     expect(el.multiple).toBe(false)
   })
 
+  // #1049
+  test('object prop', () => {
+    const el = document.createElement('video')
+    const object = {}
+    const set = jest.fn()
+    Object.defineProperty(el, 'srcObject', { enumerable: true, set })
+    patchProp(el, 'srcObject', null, object)
+    expect(set).toHaveBeenCalledWith(object)
+  })
+
   test('innerHTML unmount prev children', () => {
     const fn = jest.fn()
     const comp = {

packages/runtime-dom/src/modules/props.ts

@@ -32,6 +32,6 @@ export function patchDOMProp(
     // e.g. <select multiple> compiles to { multiple: '' }
     el[key] = true
   } else {
-    el[key] = value == null ? '' : value
+    el[key] = value
   }
 }