RFR: 8273660: De-Serialization Stack is suppressing ClassNotFoundException [v2]

[Roger Riggs]

> The ObjectInputStream.GetField method `get(String name, Object val)` should have been throwing
> a ClassNotFoundException if the class was not found.  Instead the implementation was returning null.
> A design error does not allow the `get(String name, Object val)`  method to throw CNFE as it should.
> However, an exception must be thrown to prevent invalid data from being returned.
> Wrapping the CNFE in IOException allows it to be thrown and the exception handled.
> The call to `get(String name, Object val)`  is always from within a `readObject` method
> so the deserialization logic can catch the IOException and unwrap it to handle the CNFE.

Roger Riggs has updated the pull request incrementally with one additional commit since the last revision:

  Correct comment on the handling of ClassNotFoundException

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6053/files
  - new: https://git.openjdk.java.net/jdk/pull/6053/files/bc467cab..438548e9

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6053&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6053&range=00-01

  Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6053.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6053/head:pull/6053

PR: https://git.openjdk.java.net/jdk/pull/6053