tools/jar/ChangeDir.java fails if /tmp/a exists

I see this test fail periodically in my local environment, it's a shared system and it turns out the reason is that someone else has created /tmp/a which the test also attempts to create. It would great if the test could be changed to not use a fixed file name. Attached is a sample failure when this happens (sudo rm -rf /tmp/a fixes the issue until someone else creates it again).


java.lang.Exception: Stack trace
at java.lang.Thread.dumpStack(Thread.java:1308)
at ChangeDir.fail(ChangeDir.java:118)
at ChangeDir.check(ChangeDir.java:121)
at ChangeDir.doTest(ChangeDir.java:73)
at ChangeDir.realMain(ChangeDir.java:51)
at ChangeDir.main(ChangeDir.java:126)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.sun.javatest.regtest.MainAction$SameVMRunnable.run(MainAction.java:728)
at java.lang.Thread.run(Thread.java:724)
java.io.IOException: No such file or directory
at java.io.UnixFileSystem.createFileExclusively(Native Method)
at java.io.File.createNewFile(File.java:1012)
at ChangeDir.doTest(ChangeDir.java:77)
at ChangeDir.realMain(ChangeDir.java:51)
at ChangeDir.main(ChangeDir.java:126)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.sun.javatest.regtest.MainAction$SameVMRunnable.run(MainAction.java:728)
at java.lang.Thread.run(Thread.java:724)
java.lang.AssertionError: Some tests failed
at ChangeDir.main(ChangeDir.java:128)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.sun.javatest.regtest.MainAction$SameVMRunnable.run(MainAction.java:728)
at java.lang.Thread.run(Thread.java:724)

JavaTest Message: Test threw exception: java.lang.AssertionError
JavaTest Message: shutting down test