Runtime.exec with a third argument (current working directory argument) that
refers to a nonexistant directory can cause the child process to hang.  This
is on Solaris 8 w/ 1.4.2-b18.

The following testcase will hang waiting for the hung child process:

import java.io.*;

public class FAEBug {
	public static void main(String args[]) {
		try {
		   Process p = Runtime.getRuntime().exec("/usr/bin/ls",
							 null,
							 new File("foo"));
		   p.waitFor();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

See also comments.