RFR: 6257207: JTable.getDefaultEditor throws NullPointerException [v4]

[Prasanta Sadhukhan]

> If getDefaultEditor() is called before the JTable model is setup, it results in NPE.
> 
> This is because when JTable sets its model, which ends up firing a table changed event. The testcase is listening for tableChanged events and querying the editor. But the editor isn't installed until after the model is set which results in NPE.
> Fix is to ensure initializeLocalVars() which initializes default editor is setup before JTable sets its model.
> 
> No regression is observed in jtreg/jck testsuite with this change.

Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:

  Test review fix

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/10871/files
  - new: https://git.openjdk.org/jdk/pull/10871/files/7ac0d1e8..a2c499fb

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=10871&range=03
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=10871&range=02-03

  Stats: 7 lines in 1 file changed: 1 ins; 3 del; 3 mod
  Patch: https://git.openjdk.org/jdk/pull/10871.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/10871/head:pull/10871

PR: https://git.openjdk.org/jdk/pull/10871