From 8fd26ab591cabf171babcbb9cc0b8d69927deed8 Mon Sep 17 00:00:00 2001
From: ceekeywangxu <ceekeywangxu@didiglobal.com>
Date: Thu, 21 Mar 2019 17:49:45 +0800
Subject: [PATCH] fixed nodesBetween when child is undefinded bug

---
 src/fragment.js | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/src/fragment.js b/src/fragment.js
index d1e27d7..64897e5 100644
--- a/src/fragment.js
+++ b/src/fragment.js
@@ -22,14 +22,19 @@ export class Fragment {
   // into a node when the callback returns `false`.
   nodesBetween(from, to, f, nodeStart = 0, parent) {
     for (let i = 0, pos = 0; pos < to; i++) {
-      let child = this.content[i], end = pos + child.nodeSize
-      if (end > from && f(child, nodeStart + pos, parent, i) !== false && child.content.size) {
-        let start = pos + 1
-        child.nodesBetween(Math.max(0, from - start),
-                           Math.min(child.content.size, to - start),
-                           f, nodeStart + start)
+      let child = this.content[i]
+      if (child) {
+        let end = pos + child.nodeSize
+        if (end > from && f(child, nodeStart + pos, parent, i) !== false && child.content.size) {
+          let start = pos + 1
+          child.nodesBetween(Math.max(0, from - start),
+                             Math.min(child.content.size, to - start),
+                             f, nodeStart + start)
+        }
+        pos = end
+      } else {
+        pos = to
       }
-      pos = end
     }
   }