RFR: 7903988: IDEA plugin: temp directories don't work on Windows

[Jorn Vernee]

On Mon, 14 Apr 2025 16:30:25 GMT, Christian Stein <cstein at openjdk.org> wrote:

>> Copied from the JBS issue:
>> 
>> To find the temporary directory on Windows, one of the environment variables `TMP`, `TEMP`, or `USERPROFILE` is needed [1](https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-gettemppatha#remarks). If these are not set, `C:\WINDOWS` is used as a fallback, but this directory is typically inaccessible (and generally not really a directory you want to leave temp files in).
>> 
>> The IDEA plugin currently doesn't forward these variables to the jtreg process that it starts, resulting in them being unset. For tests that e.g. create temporary files or directories, this result in an `AccessDeniedException` such as:
>> 
>> 
>> java.nio.file.AccessDeniedException: C:\\WINDOWS\\asdf12599356154200781179
>>   at java.base/sun.nio.fs.WindowsException.translateToIOException(WindowsException.java:89)
>>   at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:103)
>>   at java.base/sun.nio.fs.WindowsException.rethrowAsIOException(WindowsException.java:108)
>>   at java.base/sun.nio.fs.WindowsFileSystemProvider.newByteChannel(WindowsFileSystemProvider.java:231)
>>   at java.base/java.nio.file.Files.newByteChannel(Files.java:357)
>>   at java.base/java.nio.file.Files.createFile(Files.java:609)
>>   at java.base/java.nio.file.TempFileHelper.create(TempFileHelper.java:132)
>>   at java.base/java.nio.file.TempFileHelper.createTempFile(TempFileHelper.java:150)
>>   at java.base/java.nio.file.Files.createTempFile(Files.java:842)
>>   at TestTempDir.testTempDir(TestTempDir.java:39)
>> 
>> 
>> The plugin should forward these environment variables on Windows, to make sure that the temporary directory can be found by tests.
>> 
>> Tested locally with a simple test that calls [`Files::createTempFile`](https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/nio/file/Files.html#createTempFile(java.lang.String,java.lang.String,java.nio.file.attribute.FileAttribute...)), and checked that these changes prevent an `AccessDeniedError` from being thrown.
>
> plugins/idea/src/main/java/com/oracle/plugin/jtreg/configuration/JTRegConfigurationRunnableState.java line 111:
> 
>> 109:         javaParameters.setMainClass("com.sun.javatest.regtest.Main");
>> 110: 
>> 111:         if (JTRegUtils.IS_WINDOWS) {
> 
> What happens if `System.getenv("TMP")` returns `null`?
> 
> Wouldn't it be better to check that first for each pair, and if the value is non-null, add the pair to the  `javaParameters` instance?

That's probably better yeah. I was assuming the value would just be ignored if null. The implementation of `addEnv` just adds the value to a map.

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PR Review Comment: https://git.openjdk.org/jtreg/pull/258#discussion_r2042643569