fix(runtime-dom): consistently remove boolean attributes for falsy values (#4348)

packages/server-renderer/__tests__/ssrRenderAttrs.spec.ts

@@ -50,9 +50,11 @@ describe('ssr: renderAttrs', () => {
     expect(
       ssrRenderAttrs({
         checked: true,
-        multiple: false
+        multiple: false,
+        readonly: 0,
+        disabled: ''
       })
-    ).toBe(` checked`) // boolean attr w/ false should be ignored
+    ).toBe(` checked disabled`) // boolean attr w/ false should be ignored
   })
 
   test('ignore falsy values', () => {

packages/server-renderer/src/helpers/ssrRenderAttrs.ts

@@ -7,6 +7,7 @@ import {
   isOn,
   isSSRSafeAttrName,
   isBooleanAttr,
+  includeBooleanAttr,
   makeMap
 } from '@vue/shared'
 
@@ -52,7 +53,7 @@ export function ssrRenderDynamicAttr(
       ? key // preserve raw name on custom elements
       : propsToAttrMap[key] || key.toLowerCase()
   if (isBooleanAttr(attrKey)) {
-    return value === false ? `` : ` ${attrKey}`
+    return includeBooleanAttr(value) ? ` ${attrKey}` : ``
   } else if (isSSRSafeAttrName(attrKey)) {
     return value === '' ? ` ${attrKey}` : ` ${attrKey}="${escapeHtml(value)}"`
   } else {

packages/server-renderer/src/index.ts

@@ -27,6 +27,7 @@ export {
 export { ssrInterpolate } from './helpers/ssrInterpolate'
 export { ssrRenderList } from './helpers/ssrRenderList'
 export { ssrRenderSuspense } from './helpers/ssrRenderSuspense'
+export { includeBooleanAttr as ssrIncludeBooleanAttr } from '@vue/shared'
 
 // v-model helpers
 export {