Applying a suggesting results in 500 error - ArgumentError: 3:UserCommitFiles: empty CommitMessage

https://sentry.gitlab.net/gitlab/gitlabcom/issues/1181154/

GRPC::InvalidArgument: 3:UserCommitFiles: empty CommitMessage
  grpc/generic/active_call.rb:31:in `check_status'
    fail GRPC::BadStatus.new_status_exception(
  grpc/generic/active_call.rb:181:in `attach_status_results_and_complete_call'
    recv_status_batch_result.check_status
  grpc/generic/active_call.rb:418:in `client_streamer'
    attach_status_results_and_complete_call(batch_result)
  grpc/generic/client_stub.rb:255:in `block in client_streamer'
    c.client_streamer(requests, metadata: metadata)
  grpc/generic/interceptors.rb:170:in `intercept!'
    return yield if @interceptors.none?
...
(162 additional frame(s) were not displayed)

ArgumentError: 3:UserCommitFiles: empty CommitMessage
  gitlab/git/wraps_gitaly_errors.rb:11:in `rescue in wrapped_gitaly_errors'
    raise ArgumentError.new(e)
  gitlab/git/wraps_gitaly_errors.rb:6:in `wrapped_gitaly_errors'
    def wrapped_gitaly_errors(&block)
  gitlab/metrics/instrumentation.rb:161:in `block in wrapped_gitaly_errors'
    .measure { super }
  gitlab/metrics/method_call.rb:36:in `measure'
    retval = yield
  gitlab/metrics/instrumentation.rb:161:in `wrapped_gitaly_errors'
    .measure { super }
...
(150 additional frame(s) were not displayed)

ArgumentError: 3:UserCommitFiles: empty CommitMessage