RFR: 8333427: langtools/tools/javac/newlines/NewLineTest.java is failing on Japanese Windows

[Jaikiran Pai]

On Mon, 3 Jun 2024 11:42:08 GMT, KIRIYAMA Takuya <duke at openjdk.org> wrote:

> I fixed to get Charset from native.encoding instead of Charset.defaultCharset() when reading a file to which the output of javac run in the test was redirected.
> The modified code is based on the alternatives given in JEP400.
> I verified that the test passed on Windows in both Japanese and English locales with this fix.

test/langtools/tools/javac/newlines/NewLineTest.java line 61:

> 59:                 .run(Task.Expect.FAIL);
> 60: 
> 61:         String encoding = System.getProperty("native.encoding");

Hello @tkiriyama, I don't have experience in javac area or this test, but I had a brief look at this change. What I understand is that `javac` will print to `STDOUT` using a `PrinterWriter` for `System.out`, which as per the documentation https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/lang/System.html#out will use `stdout.encoding` value for the character encoding. The default value of `stdout.encoding` standard system property https://docs.oracle.com/en/java/javase/22/docs/api/java.base/java/lang/System.html#stdout.encoding is currently not mentioned but I checked with people familiar with this area and it defaults to platform specific values. It is not guaranteed that `stdout.encoding` will be the same value as `native.encoding`. So the proposed change here isn't guaranteed to (always) work.

I think to make this deterministic, you might have to update the `javac` launch command (a few lines above) to pass `-J-Dstdout.encoding=UTF-8` and then when reading from the file to which the content was redirected, use `StandardCharsets.UTF_8`.
Can you give that change a try on your setup and see if it solves the issue for you?

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PR Review Comment: https://git.openjdk.org/jdk/pull/19519#discussion_r1639370650