Currently the default using of "Porter" stemming means that certain search phrases do not return results that the user might expect.
For example if the issue summary is "Moose problems" then the default stemming will cause "moos" to be stored in the index.
If the user then enters a search request for "Moose" then no match will be made. The reason is that the Lucene QueryParser code does NOT perform analysis on "Prefix" queries by default.
Hence a PrefixQuery for the term "moose" is submitted and the index doent contain this terms and hence no issue is returned.
The improvement would be to tweak QueryParser so that it does perform "analysis" on prefix queries. So the term "moose" would be stemmed to "moos" and then the Prefix Query would return the expected results.