Bug#389332: iskeyword in ftplugin/ruby.vim causes problems

[Tim Pope]

Setting iskeyword+=?,! has side effects.  In Ruby, method names can
end in these two characters.  However, they have other valid meanings
as well; ! means "not" and ? is part of the ? : operator, as in many
other languages.  The syntax highlighting file depends on iskeyword
remaining at its default and changing it causes code like
!File.exists?(".vimrc") to highlight incorrectly.

Because of the way ri searches, omitting the ? or ! from the method
name (as would happen if the iskeyword line is removed) will not
typically impact the results.

Thanks,
Tim Pope