EmptyWhen should not be reported when there is an else block

[rpherbig]

Rubocop should not report a warning on a case block with an "empty when" if it also has an else block. This style is useful to indicate that in some cases/whens, no action is necessary.

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Expected behavior

Rubocop should not report a warning on a case block with an "empty when" if it also has an else block.

Actual behavior

Rubocop reports a warning that an "empty when" exists:

$ rubocop temp.rb
Inspecting 1 file
W

Offenses:

temp.rb:9:1: W: Avoid when branches without a body.
when 'something else'
^^^^^^^^^^^^^^^^^^^^^

1 file inspected, 1 offense detected

Steps to reproduce the problem

def handle_foo
  puts 'foo'
end

input = 'foo'
case input
when 'foo'
  handle_foo
when 'something else'
  # nothing needs to happen
else
  puts 'unexpected value!'
end

RuboCop version

Include the output of rubocop -V. Here's an example:

$ rubocop -V
0.45.0 (using Parser 2.3.3.0, running on ruby 2.0.0 i386-mingw32)

[tejasbubane]

Duplicate of #3696 Can be closed.

[mrpinsky]

Bump for closing as duplicate @bbatsov