use sameVnode check when pacthing keyed children (fix vuejs#4393)

yyx990803 · yyx990803 · commit 58949bd1c5c4 · 2016-12-08T12:26:22.000-05:00
diff --git a/src/core/vdom/patch.js b/src/core/vdom/patch.js
@@ -386,15 +386,15 @@ export function createPatchFunction (backend) {
               'Make sure each v-for item has a unique key.'
             )
           }
-          if (elmToMove.tag !== newStartVnode.tag) {
-            // same key but different element. treat as new element
-            createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm)
-            newStartVnode = newCh[++newStartIdx]
-          } else {
+          if (sameVnode(elmToMove, newStartVnode)) {
             patchVnode(elmToMove, newStartVnode, insertedVnodeQueue)
             oldCh[idxInOld] = undefined
             canMove && nodeOps.insertBefore(parentElm, newStartVnode.elm, oldStartVnode.elm)
             newStartVnode = newCh[++newStartIdx]
+          } else {
+            // same key but different element. treat as new element
+            createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm)
+            newStartVnode = newCh[++newStartIdx]
           }
         }
       }

Original file line number	Diff line number	Diff line change
`@@ -386,15 +386,15 @@ export function createPatchFunction (backend) {`
`386`	`386`	`'Make sure each v-for item has a unique key.'`
`387`	`387`	`)`
`388`	`388`	`}`
`389`		`- if (elmToMove.tag !== newStartVnode.tag) {`
`390`		`- // same key but different element. treat as new element`
`391`		`- createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm)`
`392`		`- newStartVnode = newCh[++newStartIdx]`
`393`		`- } else {`
	`389`	`+ if (sameVnode(elmToMove, newStartVnode)) {`
`394`	`390`	`patchVnode(elmToMove, newStartVnode, insertedVnodeQueue)`
`395`	`391`	`oldCh[idxInOld] = undefined`
`396`	`392`	`canMove && nodeOps.insertBefore(parentElm, newStartVnode.elm, oldStartVnode.elm)`
`397`	`393`	`newStartVnode = newCh[++newStartIdx]`
	`394`	`+ } else {`
	`395`	`+ // same key but different element. treat as new element`
	`396`	`+ createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm)`
	`397`	`+ newStartVnode = newCh[++newStartIdx]`
`398`	`398`	`}`
`399`	`399`	`}`
`400`	`400`	`}`