SIGSEGV in libzmq zmq::trie_t::check

[Wojtek42]

Issue description

I hit a SIGSEGV using the libzmq library wrapped in jzmq

Environment

Java(TM) SE Runtime Environment (7.0_79-b15) (build 1.7.0_79-b15)

libzmq version (commit hash if unreleased):
4.1.2
jzmq-3.1.0.jar

OS:
Linux 2.6.32-642.11.1.el6.x86_64

Minimal test code / Steps to reproduce the issue

Not able to reproduce. Occurred once.

What's the actual result? (include assertion message & call stack if applicable)

Stack: [0x00007f04e2cb8000,0x00007f04e2db9000], sp=0x00007f04e2db7568, free space=1021k
Native frames: (J=compiled Java code, j=interpreted, Vv=VM code, C=native code)
C [libzmq.so.5+0x40cd2] zmq::trie_t::check(unsigned char*, unsigned long)+0x72

Java frames: (J=compiled Java code, j=interpreted, Vv=VM code)
J 1097 org.zeromq.ZMQ$Socket.recv(I)[B (0 bytes) @ 0x00007f0521230498 [0x00007f0521230460+0x38]