RFR: 8320798: Console read line with zero out should zero out underlying buffer [v3]

[Naoto Sato]

> It is best practice to zero out the underlying buffer after use.

Naoto Sato has updated the pull request incrementally with one additional commit since the last revision:

  remove ensureOpen()

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/16861/files
  - new: https://git.openjdk.org/jdk/pull/16861/files/90c4dece..6d2d6368

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=16861&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=16861&range=01-02

  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/16861.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/16861/head:pull/16861

PR: https://git.openjdk.org/jdk/pull/16861