OK, I did a little more research into this. The globStatus code back in 2.0.3-alpha does sort the entries it returned. Around Hadoop 2.3, the sort was lost during the globber rewrite. This was a bug, but it was hidden by the fact that HDFS sorts its listStatus entries (this behavior is undocumented, but 100% consistent).
Since the API documentation says that sorted entries are returned, and since this is the case for the vast majority of use-cases (i.e. when using Hadoop with HDFS), I think changing this behavior in globStatus would be an incompatible change. Any user code relying on the old documented behavior would break. Let's commit the original patch I posted to fix this situation. If we want to have a discussion about changing the API contract we can have that discussion for Hadoop 3.0 only.
also I feel that the facts that:
1. globStatus has historically had a sort in it
2. users who want to optimize by avoiding a sort can use listStatus
strongly suggest that changing this behavior is not a good idea, even in 3.x.