Error on redoing new line/paragraph

[mshamaiev-intel471]

Error when trying to redo new line/paragraph
quill.js:5216 Uncaught TypeError: leaf.position is not a function

Steps for Reproduction

1. Visit beta.quilljs.com
2. Hit Enter
3. Hit undo Cmd+Z
4. Hit redo Cmd+Shift+Z

Expected behavior: correct redoing of new line

Actual behavior: no new line and error in console

Platforms: Firefox 47, Firefox 49a and Chrome 51 on OS X 10.11.5

Version: 1.0.0-beta.6

[benbro]

Related?
#740

[jhchen]

The two have different stack traces but it's likely the it is same root cause of being in an invalid state. The referenced commit fixes this one's for sure, given the reproduction steps.