use push instead of replace in ensureURL (#894)

* use push instead of replace in ensureURL

* add parameter push to ensureURL, for next(false)

Author: yyx990803

src/history/base.js

@@ -18,7 +18,7 @@ export class History {
   go: (n: number) => void;
   push: (loc: RawLocation) => void;
   replace: (loc: RawLocation) => void;
-  ensureURL: () => void;
+  ensureURL: (push?: boolean) => void;
 
   constructor (router: VueRouter, base: ?string) {
     this.router = router
@@ -70,7 +70,7 @@ export class History {
       hook(route, current, (to: any) => {
         if (to === false) {
           // next(false) -> abort navigation, ensure current URL
-          this.ensureURL()
+          this.ensureURL(true)
         } else if (typeof to === 'string' || typeof to === 'object') {
           // next('/') or next({ path: '/' }) -> redirect
           this.push(to)

src/history/hash.js

@@ -52,9 +52,10 @@ export class HashHistory extends History {
     window.history.go(n)
   }
 
-  ensureURL () {
-    if (getHash() !== this.current.fullPath) {
-      replaceHash(this.current.fullPath)
+  ensureURL (push?: boolean) {
+    const current = this.current.fullPath
+    if (getHash() !== current) {
+      push ? pushHash(current) : replaceHash(current)
     }
   }
 }

src/history/html5.js

@@ -57,9 +57,10 @@ export class HTML5History extends History {
     })
   }
 
-  ensureURL () {
+  ensureURL (push?: boolean) {
     if (getLocation(this.base) !== this.current.fullPath) {
-      replaceState(cleanPath(this.base + this.current.fullPath))
+      const current = cleanPath(this.base + this.current.fullPath)
+      push ? pushState(current) : replaceState(current)
     }
   }