escaping bug in ri

[ddebernardy]

I was trying to lookup the ri for []:

DB:~ $ ri []
/opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:744: warning: character class has ']' without escape: /^[][^:]*$/
/opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:744:in `block (2 levels) in expand_class': premature end of char-class: /^[][^:]*$/ (RegexpError)
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:743:in `select'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:743:in `block in expand_class'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:739:in `each'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:739:in `inject'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:739:in `expand_class'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:766:in `expand_name'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:728:in `block in display_names'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:727:in `each'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:727:in `display_names'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:1128:in `run'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:324:in `run'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/bin/ri:5:in `<top (required)>'
    from /opt/local/bin/ri:19:in `load'
    from /opt/local/bin/ri:19:in `<main>'
DB:~ $ ri \[\]
/opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:744: warning: character class has ']' without escape: /^[][^:]*$/
/opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:744:in `block (2 levels) in expand_class': premature end of char-class: /^[][^:]*$/ (RegexpError)
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:743:in `select'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:743:in `block in expand_class'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:739:in `each'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:739:in `inject'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:739:in `expand_class'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:766:in `expand_name'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:728:in `block in display_names'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:727:in `each'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:727:in `display_names'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:1128:in `run'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/lib/rdoc/ri/driver.rb:324:in `run'
    from /opt/local/lib/ruby1.9/gems/1.9.1/gems/rdoc-3.8/bin/ri:5:in `<top (required)>'
    from /opt/local/bin/ri:19:in `load'
    from /opt/local/bin/ri:19:in `<main>'

[drbrain]

Looks like I missed a case.

As a workaround you can use Array.[] or Hash.[]

[drbrain]

Fixed by @8c87409