hg: jdk10/sandbox/jdk: 8178821: jshell tool: ctrl-down does nothing in current context

[chris.hegarty at oracle.com]

Changeset: 4227b6c51e92
Author:    jlahoda
Date:      2017-04-20 18:40 +0200
URL:       http://hg.openjdk.java.net/jdk10/sandbox/jdk/rev/4227b6c51e92

8178821: jshell tool: ctrl-down does nothing in current context
Summary: In MemoryHistory index() of an entry may go beyond size() (if some leading entries have been deleted) - using previous()/next() instead.
Reviewed-by: rfield

! src/jdk.internal.le/share/classes/jdk/internal/jline/extra/EditingHistory.java
! test/jdk/internal/jline/extra/HistoryTest.java