Bug 268684

Product Version = NetBeans IDE 8.2 (Build 201609300101)
Operating System = Windows 10 version 10.0 running on amd64
Java; VM; Vendor = 1.8.0_102
Runtime = Java HotSpot(TM) 64-Bit Server VM 25.102-b14

Reproducibility: Happens every time

STEPS:
  * Open a Groovy file (at least 300 lines)
  * Open a Java file.
  * Clone the Java file window (at least 300 lines)
  * Clone the Groovy file 

 -- Now have 4 x editor windows  Groovy.1 and Groovy.2, Java.1 and Java.2

  * Navigate and edit near the end of the Groovy.1 window
  * In the Groovy.2 window edit in the middle of the file

  * Navigate and edit near the end of the Java.1 window
  * In the Java.2 window edit in the middle of the file

ACTUAL:
  After some time Both of the Groovy windows put the cursor on the SAME line 
  Instead of keeping a separate edit context for each.
  Further sometimes one of the Groovy windows may jump at random in response to a paste or cut instructiion.

  As far as I know Java windows Keep things in the correct location on Netbeans 8.1  I am not sure yet if the Java windows jump around like this on 8.2 (yet).  
  As there have been some odd occurences.

  This is definitely confirmed for Groovy.

EXPECTED:
  The edit location and cursor should be independent in EACH open window.

  The reason to use multiple windows in a long file is to be able to view different and related areas at the same time.
  This behaviour causes errors, lots time and now and again bugs because we didn't see we pasted or typed to the wrong part of the file.