PIG-3144: Erroneous map entry alias resolution leading to "Duplicate schema alias" errors (jcoveney via cheolsoo)


git-svn-id: https://svn.apache.org/repos/asf/pig/trunk@1452460 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'trunk' of https://github.com/apache/pig into trunk