fix(history): Resolve the href in <base> correctly (#3819)

* Resolve the href in `<base>` correctly.

* In hash mode, the hash in base is automatically removed and the base trailing slash is distinguished.

* By default the result of `router.resolve().href` is the same as the actual switched URL.

Author: ichaoX

Diff for: examples/hash-mode/app.js

@@ -40,7 +40,7 @@ const Query = { template: '<div>query: "{{ $route.params.q }}"</div>' }
 // 3. Create the router
 const router = new VueRouter({
   mode: 'hash',
-  base: __dirname,
+  base: require('path').join(__dirname, '/#hash'),
   routes: [
     { path: '/', component: Home }, // all paths are defined without the hash.
     { path: '/foo', component: Foo },

Diff for: src/history/base.js

@@ -272,19 +272,27 @@ function normalizeBase (base: ?string): string {
     if (inBrowser) {
       // respect <base> tag
       const baseEl = document.querySelector('base')
-      base = (baseEl && baseEl.getAttribute('href')) || '/'
-      // strip full URL origin
-      base = base.replace(/^https?:\/\/[^\/]+/, '')
+      base = (baseEl && baseEl.getAttribute('href') && typeof baseEl.href === 'string') ? baseEl.href : ''
+      if (base) {
+        const href = window.location.href
+        const locationOrigin = href.replace(/^([^\/]+:\/\/[^\/]*)?.*$/, '$1')
+        const baseOrigin = base.replace(/^([^\/]+:\/\/[^\/]*)?.*$/, '$1')
+        if (locationOrigin === baseOrigin) {
+          base = base.slice(baseOrigin.length)
+        } else {
+          // XXX: hash and history modes do not support cross-origin
+          base = locationOrigin
+        }
+      }
     } else {
-      base = '/'
+      base = ''
     }
   }
   // make sure there's the starting slash
-  if (base.charAt(0) !== '/') {
+  if (base && base.charAt(0) !== '/' && !base.match(/^[^\/]+:\/\//)) {
     base = '/' + base
   }
-  // remove trailing slash
-  return base.replace(/\/$/, '')
+  return base
 }
 
 function resolveQueue (

Diff for: src/history/hash.js

@@ -10,6 +10,7 @@ import { pushState, replaceState, supportsPushState } from '../util/push-state'
 export class HashHistory extends History {
   constructor (router: Router, base: ?string, fallback: boolean) {
     super(router, base)
+    this.base = normalizeHashBase(this.base, !base)
     // check history fallback deeplinking
     if (fallback && checkFallback(this.base)) {
       return
@@ -135,6 +136,17 @@ function getUrl (path) {
   return `${base}#${path}`
 }
 
+function normalizeHashBase (base: string, replace: ?boolean): string {
+  if (!base) return ''
+  if (replace) {
+    const hasOrigin = !!base.match(/^[^\/]+:\/\/[^\/]+/)
+    base = window.location.href
+    // XXX: keep origin for possible cross-origin cases
+    if (!hasOrigin) base = base.replace(/^[^\/]+:\/\/[^\/]+/, '')
+  }
+  return base.replace(/#.*$/, '')
+}
+
 function pushHash (path) {
   if (supportsPushState) {
     pushState(getUrl(path))

Diff for: src/history/html5.js

@@ -58,7 +58,7 @@ export class HTML5History extends History {
   push (location: RawLocation, onComplete?: Function, onAbort?: Function) {
     const { current: fromRoute } = this
     this.transitionTo(location, route => {
-      pushState(cleanPath(this.base + route.fullPath))
+      pushState(cleanPath(route.fullPath, this.base))
       handleScroll(this.router, route, fromRoute, false)
       onComplete && onComplete(route)
     }, onAbort)
@@ -67,15 +67,15 @@ export class HTML5History extends History {
   replace (location: RawLocation, onComplete?: Function, onAbort?: Function) {
     const { current: fromRoute } = this
     this.transitionTo(location, route => {
-      replaceState(cleanPath(this.base + route.fullPath))
+      replaceState(cleanPath(route.fullPath, this.base))
       handleScroll(this.router, route, fromRoute, false)
       onComplete && onComplete(route)
     }, onAbort)
   }
 
   ensureURL (push?: boolean) {
     if (getLocation(this.base) !== this.current.fullPath) {
-      const current = cleanPath(this.base + this.current.fullPath)
+      const current = cleanPath(this.current.fullPath, this.base)
       push ? pushState(current) : replaceState(current)
     }
   }

Diff for: src/router.js

@@ -279,7 +279,9 @@ function registerHook (list: Array<any>, fn: Function): Function {
 
 function createHref (base: string, fullPath: string, mode) {
   var path = mode === 'hash' ? '#' + fullPath : fullPath
-  return base ? cleanPath(base + '/' + path) : path
+  // '/main.html#/foo' should not be converted to '/main.html/#/foo'
+  if (base && mode !== 'hash') base = base.replace(/\/?$/, '/')
+  return base ? cleanPath(path, base) : path
 }
 
 // We cannot remove this as it would be a breaking change

Diff for: src/util/path.js

@@ -69,6 +69,17 @@ export function parsePath (path: string): {
   }
 }
 
-export function cleanPath (path: string): string {
-  return path.replace(/\/(?:\s*\/)+/g, '/')
+export function cleanPath (path: string, base: ?string): string {
+  let prefix = ''
+  if (base) {
+    // allow base to specify an origin
+    const match = base.match(/^((?:[^\/]+:)?\/\/)/)
+    if (match) {
+      prefix = match[0]
+      path = base.slice(prefix.length) + path
+    } else {
+      path = base + path
+    }
+  }
+  return prefix + path.replace(/\/(?:\s*\/)+/g, '/')
 }