Compilation error when Speaker list is empty

If the speaker-list of a talk is empty, we end up accessing a nil value during compilation:

bundle exec nanoc
Loading site… done
Compiling site…

Captain! We’ve been hit!

Message:

NoMethodError: undefined method `join' for nil:NilClass

Stack trace:

  0. lib/ical_helpers.rb:9:in `generate_event'
  1. lib/ical_helpers.rb:22:in `block in generate_ical_items'
  2. lib/ical_helpers.rb:21:in `each'
  3. lib/ical_helpers.rb:21:in `generate_ical_items'
  4. /home/clouduser/UnFUG/unfug.org/Rules:17:in `block in parse'
  5. /home/clouduser/.gem/ruby/2.3.0/gems/nanoc-4.8.10/lib/nanoc/rule_dsl/action_provider.rb:49:in `instance_eval'
  6. /home/clouduser/.gem/ruby/2.3.0/gems/nanoc-4.8.10/lib/nanoc/rule_dsl/action_provider.rb:49:in `block in preprocess'
  7. /home/clouduser/.gem/ruby/2.3.0/gems/nanoc-4.8.10/lib/nanoc/rule_dsl/action_provider.rb:48:in `each_value'
  8. /home/clouduser/.gem/ruby/2.3.0/gems/nanoc-4.8.10/lib/nanoc/rule_dsl/action_provider.rb:48:in `preprocess'
  9. /home/clouduser/.gem/ruby/2.3.0/gems/nanoc-4.8.10/lib/nanoc/base/services/compiler/stages/preprocess.rb:17:in `run'
  ... 37 more lines omitted. See full crash log for details.

If you believe this is a bug in Nanoc, please do report it at
-> https://github.com/nanoc/nanoc/issues/new <-

A detailed crash log has been written to ./crash.log.
make: *** [Makefile:2: all] Error 1

hfuunfug / unfug.org

Compilation error when Speaker list is empty #102