From: John Carter <john.carter@...>
Date: 2005-01-17T10:51:30+09:00
Subject: Bug in ri - cannot convert nil into Array

There seems to be a Bug in "ri" in the CVS-Latest (17-Jan-2005) version of 
Ruby.

ri Set | cat
/usr/local/lib/ruby/1.9/rdoc/ri/ri_descriptions.rb:99:in `concat': cannot 
convert nil into Array (TypeError)
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_descriptions.rb:99:in 
`merge_in'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_reader.rb:56:in 
`get_class'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_reader.rb:52:in `each'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_reader.rb:52:in 
`get_class'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_reader.rb:31:in 
`find_class_by_name'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_display.rb:97:in 
`display_class_info'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_display.rb:96:in `each'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_display.rb:96:in 
`display_class_info'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_display.rb:77:in `page'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_display.rb:77:in 
`display_class_info'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_driver.rb:71:in 
`report_class_stuff'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_driver.rb:106:in 
`get_info_for'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_driver.rb:135:in 
`process_args'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_driver.rb:134:in `each'
 	from /usr/local/lib/ruby/1.9/rdoc/ri/ri_driver.rb:134:in 
`process_args'
 	from /usr/local/bin/ri:48
------------------------------------------------------------- Class: Set
      Set implements a collection of unordered values with no duplicates.
      This is a hybrid of Array's intuitive inter-operation facilities
      and Hash's fast lookup.

      Several methods accept any Enumerable object (implementing +each+)
      for greater flexibility: new, replace, merge, subtract, |, &, -, ^.

      The equality of each couple of elements is determined according to
      Object#eql? and Object#hash, since Set uses Hash as storage.

      Finally, if you are using class Set, you can also use
      Enumerable#to_set for convenience.


Example
-------
        require 'set'
        s1 = Set.new [1, 2]                   # -> #<Set: {1, 2}>
        s2 = [1, 2].to_set                    # -> #<Set: {1, 2}>
        s1 == s2                              # -> true
        s1.add("foo")                         # -> #<Set: {1, 2, "foo"}>
        s1.merge([2, 6])                      # -> #<Set: {6, 1, 2, "foo"}>
        s1.subset? s2                         # -> false
        s2.subset? s1                         # -> true

------------------------------------------------------------------------


Includes:
---------

====================================================================

If I have a look at
/usr/local/lib/ruby/1.9/rdoc/ri/ri_descriptions.rb:99, I see...
     # merge in another class desscription into this one
     def merge_in(old)
       merge(@class_methods, old.class_methods)
       merge(@instance_methods, old.instance_methods)
       merge(@attributes, old.attributes)
       merge(@constants, old.constants)
       merge(@includes, old.includes)
       if @comment.nil? || @comment.empty?
         @comment = old.comment
       else
         @comment << SM::Flow::RULE.new
         @comment.concat old.comment
       end
     end

Where line 99 is...
         @comment.concat old.comment

I take it then "old.comment" is nil

Give me a yell if you want me to doing any testing / instrumenting of this 
for you.



John Carter                             Phone : (64)(3) 358 6639
Tait Electronics                        Fax   : (64)(3) 359 4632
PO Box 1645 Christchurch                Email : john.carter@tait.co.nz
New Zealand

"The notes I handle no better than many pianists. But the pauses
  between the notes -
  ah, that is where the art resides!' - Artur Schnabel