Invalid XML causes OOM

[garthk]

$ node
> require('xmlpoke')('<test><![CDATA[hello]]</test>', xml => { return; })

<--- Last few GCs --->

   22170 ms: Mark-sweep 1290.6 (1349.6) -> 1290.6 (1350.6) MB, 1366.8 / 0 ms [allocation failure] [GC in old space requested].
   23550 ms: Mark-sweep 1290.6 (1350.6) -> 1290.6 (1350.6) MB, 1379.9 / 0 ms [last resort gc].
   24962 ms: Mark-sweep 1290.6 (1350.6) -> 1290.6 (1349.6) MB, 1411.4 / 0 ms [last resort gc].


<--- JS stacktrace --->

==== JS stack trace =========================================

Security context: 0x3494ec2c9e31 <JS Object>
    1: appendChild […/node_modules/xmldom/dom.js:~731] [pc=0x32adbec0f6f9] (this=0xc07a6f0261 <an Element with map 0x1f279eb61539>,newChild=0x28dbf8e248d1 <a Text with map 0x1f279eb61489>)
    2: characters […/node_modules/xmlpoke/node_modules/xmldom/dom-parser.js:136] [pc=0x32adbec079e5] (this=0xc07a6ebdf9 <a DO...

FATAL ERROR: CALL_AND_RETRY_LAST Allocation failed - JavaScript heap out of memory

Node 6.3.1 on Mac OS X 10.11.6. xmldom's parseFromString survives:

$ node
> new (require('xmldom').DOMParser)().parseFromString('<test><![CDATA[hello]]</test>')
Document {
  implementation: { _features: {} },
  childNodes: 
…

[mikeobrien]

Thx for the info! I'll try to look at it when I can but I'm pretty swamped ATM so I'm not sure when I'll have time. I'd totally be open to a PR if you feel like tackling it.