RFR(XS) 8218029 [TESTBUG] Use -Djava.class.path= to specify empty -cp in CDS tests

[Ioi Lam]

Hi Calvin,

The command-line that you gave (on the Linux shell) would pass the empty 
string as the value for -cp.

However, in the JTREG test cases included in this patch, the 
command-line that's executed is effectively the following as typed in a 
Linux shell

$ java -cp \"\" MyApp

Here's a way to reproduce the problem. You can see that the string with 
2 double quote characters were recorded in the NON_EXIST part of the CDS 
archive. That's not the intention of the test case.

================

$ echo sun/tools/jar/Main > classlist

$ java -Xshare:dump -cp \"\" -XX:SharedClassListFile=classlist -verbose 
| grep Main
[0.100s][info][class,load] sun.tools.jar.Main source: jrt:/jdk.jartool
[0.103s][info][class,load] sun.tools.jar.Main$CRC32OutputStream source: 
jrt:/jdk.jartool
[0.106s][info][class,load] sun.tools.jar.Main$ModuleInfoEntry source: 
jrt:/jdk.jartool

$ tbjava -Xshare:on -XX:+PrintSharedArchiveAndExit
[0.002s][info][class,path] opened: /jdk/bld/sandbox/images/jdk/lib/modules
[0.007s][info][class,path] type=BOOT
[0.007s][info][class,path] Expecting BOOT 
path=/jdk/bld/sandbox/images/jdk/lib/modules
[0.007s][info][class,path] ok
[0.007s][info][class,path] type=APP
[0.007s][info][class,path] Expecting -Djava.class.path=""
[0.007s][info][class,path]
[0.007s][info][class,path] Run time APP classpath is shorter than the 
one at dump time:
[0.007s][info][class,path] type=NON_EXIST
[0.007s][info][class,path] Expecting that "" does not exist
[0.007s][info][class,path] ok
[0.007s][info][class,path] checking shared classpath entry: 
/jdk/bld/sandbox/images/jdk/lib/modules
[0.007s][info][class,path] ok
archive is invalid
================

Thanks

- Ioi


On 1/30/19 3:03 PM, Calvin Cheung wrote:
> Hi Ioi,
>
> The fix looks fine but I'm not sure if it is necessary.
>
> I've tried the following on linux and windows and the java.class.path 
> property is not set.
>
> java -cp "" MyApp
>
> MyApp just display all system properties as follows:
>
>         Properties properties = System.getProperties();
>
>         properties.forEach((k, v) -> System.out.println(k + ":" + v));
>
> thanks,
> Calvin
>
> On 1/29/19, 7:51 PM, Ioi Lam wrote:
>> https://bugs.openjdk.java.net/browse/JDK-8218029
>> http://cr.openjdk.java.net/~iklam/jdk13/8218029-testbug-empty-classpath.v01/ 
>>
>>
>> Please review this simple fix. For portability,
>>
>>      "-cp", "\"\"",
>>
>> in the JVM command-line is replaced with
>>
>>      "-Djava.class.path="
>>
>>
>> Thanks!
>>
>> Ioi
>>