Issue #9125 has been reported by pveselov (Pawel Veselov).

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Bug #9125: Net::SMTP - invalid method raised when attempting to connect using STARTTLS
https://bugs.ruby-lang.org/issues/9125

Author: pveselov (Pawel Veselov)
Status: Open
Priority: Normal
Assignee: 
Category: lib
Target version: 
ruby -v: ruby 2.0.0p247 (2013-06-27 revision 41674) [x86_64-linux]
Backport: 1.9.3: UNKNOWN, 2.0.0: UNKNOWN


Simple attempt (in irb):

require 'net/smtp'
smtp = Net::SMTP.new('server', 587)
mtp.enable_starttls()
smtp.start()

NoMethodError: undefined method `success?' for "200 dummy reply code":String
	from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/smtp.rb:949:in `check_response'
	from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/smtp.rb:554:in `do_start'
	from /usr/local/rvm/rubies/ruby-2.0.0-p247/lib/ruby/2.0.0/net/smtp.rb:525:in `start'
	from (irb):9
	from /usr/local/rvm/rubies/ruby-2.0.0-p247/bin/irb:13:in `<main>'

The problem is with the critical() method, the method returns the "dummy response" if there already was a pending error.
The fix is to replace the line of:

      return '200 dummy reply code' if @error_occured

to

      return Response.parse('200 dummy reply code') if @error_occured

Alternatively, one can have a "canned" dummy response instance, but that may be unnecessary considering this only happens in error path.



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