fix: do not handle false + move into lower branch

Author: yyx990803

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

@@ -39,15 +39,15 @@ describe(`runtime-dom: style patching`, () => {
     const el = document.createElement('div')
     patchProp(el, 'style', null, {
       color: undefined,
-      '--color': false,
       borderRadius: null
     })
     expect(el.style.cssText.replace(/\s/g, '')).toBe('')
+
     patchProp(
       el,
       'style',
       { color: 'red' },
-      { color: undefined, '--color': false, borderRadius: false }
+      { color: null, borderRadius: undefined }
     )
     expect(el.style.cssText.replace(/\s/g, '')).toBe('')
   })

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

@@ -42,10 +42,10 @@ function setStyle(
   name: string,
   val: string | string[]
 ) {
-  val = val == null || (val as any) === false ? '' : val
   if (isArray(val)) {
     val.forEach(v => setStyle(style, name, v))
   } else {
+    if (val == null) val = ''
     if (name.startsWith('--')) {
       // custom property definition
       style.setProperty(name, val)