merge revision(s) 50444: [Backport #11128]
* lib/net/imap.rb (body_ext_mpart): should work even if body-fld-dsp is omitted. [ruby-core:69093] [Bug #11128]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@50583 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 50444: [Backport #11128]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_1@50583 b2dd03c8-39d4-4d8f-98ff-823fe69b080e