We have not upgraded HttpClient version for long time (since SOLR-6865 was committed). It may be a good idea to upgrade to the latest stable version (which is 4.5.3).
precommit should fail the build if any jar sha1 files contain any whitespace or newlines
Upgrade httpclient and httpmime to 4.5.1, httpcore to 4.4.3
GitHub Pull Request #230