From: http://jira.codehaus.org/browse/JRUBY-5617. Works JRuby 1.7.18 (with discrepancies), fails on JRuby 9000.

IO#ready? returns incorrect results on second and subsequent calls.

a) Write 100 bytes to a sender socket, issue flush, keep socket open
b) Attempt 4 consecutive reads of 25 bytes each. Check IO#ready? before reading

Expected results: 100 bytes are read in 4 consecutive reads
Observed results: The first 25 bytes are read, but then the read socket never shows ready again.

Sample code is attached. Compare JRuby behavior with 'standard' Ruby using this code.