RFR: 8073061: (fs) Files.copy(foo, bar, REPLACE_EXISTING) deletes bar even if foo is not readable [v6]

[Brian Burkhalter]

> Check that the source is readable before deleting the destination.

Brian Burkhalter has updated the pull request incrementally with one additional commit since the last revision:

  8073061: Tweak CopyMoveHelper.copyToForeignTarget

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/15501/files
  - new: https://git.openjdk.org/jdk/pull/15501/files/ec6c7ddd..8b5f3bcc

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15501&range=05
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15501&range=04-05

  Stats: 20 lines in 1 file changed: 10 ins; 9 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15501.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15501/head:pull/15501

PR: https://git.openjdk.org/jdk/pull/15501