def diff(differ_class, from, to, options={})
if from.respond_to?(:valid_encoding?) and not from.valid_encoding?
from = from.dup.force_encoding("ASCII-8BIT")
end
if to.respond_to?(:valid_encoding?) and not to.valid_encoding?
to = to.dup.force_encoding("ASCII-8BIT")
end
differ = differ_class.new(from.split(/\r?\n/), to.split(/\r?\n/))
lines = differ.diff(options)
if Object.const_defined?(:EncodingError)
begin
lines.join("\n")
rescue EncodingError
lines.collect {|line| line.force_encoding("ASCII-8BIT")}.join("\n")
end
else
lines.join("\n")
end
end