Problem with field separator in FieldSelectionHelper

[韦锴 Wei Kai <ka...@gmail.com>]

I found that org.apache.hadoop.mapreduce.lib.fieldsel.FieldSelectionHelper
and the corresponding old
api org.apache.hadoop.mapred.lib.FieldSelectionMapReduce take user
specified separator string as a regular expression in String.split(), but
also use it as a normal string in StringBuffer.append(). It will be a
problem if the separator string contains meta character. I suggest take
separator literally by calling Pattern.quote(separator). Or just use
another property to specify the separator which should be added in the
output.

If this is not a known problem, I will file a jira issue and submit the fix.