In jurt/source/pipe/com_sun_star_lib_connections_pipe_PipeConnection.c, handling
of Java exceptions is broken.  For example, ThrowException and MonitorExit are
called without a previous call to ExceptionClear, and state ACQUIRED is not
catered for in the error-handling code of
Java_com_sun_star_lib_connections_pipe_PipeConnection_readJNI.

The following is some prototypical code to use:
  void native_fn(jobect o) {
    if (env->MonitorEnter(o) < 0) return;
    // ...
    if (env->FindClass("...") == 0) {
      // Some Java exception occurred while
      // within the monitor, exit the monitor and
      // return with a Java exception pending:
      jthrowable e = env->ExceptionOccurred();
      assert e != 0;
      env->ExceptionClear();
      if (env->MonitorExit(o) == 0) {
        env->Throw(e); // even if Throw returns < 0,
                       // it is guaranteed that *some*
                       // exception is being thrown,
                       // right?
      }
      return;
    }
    // ...
    env->MonitorExit(o);
  }