Prevent NPE if ref can't be resolved when executing ReflogCommand

If the specified ref can't be resolved we should throw a
RefNotFoundException instead of an NPE.

Bug: 455005
Change-Id: I6ec9bf1c0f330eea5eb8277268f62663bdf58f66
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
RepoCommand should close opened repos

RepoCommand opend two repos without closing them or returning them to
the caller. This caused certain tests to fail on Windows.

Change-Id: Ia04924aaaad4d16f883b06404c2a85d3f801231f
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Merge "Prevent NPE if ref can't be resolved when executing ReflogCommand" into stable-3.6
Fix tests on windows by closing repos

Without explicitly closing repos we can't delete the test repositories
on windows.

Change-Id: Id5fa17bd764cbf28703c2f21639d7e969289c2d6
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>
Merge "Fix tests on windows by closing repos" into stable-3.6