RFR: 8347831: Re-examine version check when cross linking [v8]

[Alan Bateman]

On Thu, 20 Nov 2025 19:01:53 GMT, Henry Jen <henryjen at openjdk.org> wrote:

>> src/jdk.jlink/share/classes/jdk/tools/jlink/internal/JlinkTask.java line 259:
>> 
>>> 257: 
>>> 258:             try (var r = new BufferedReader(new InputStreamReader(release.get()))) {
>>> 259:                 return Optional.of(r.readLine());
>> 
>> As suggested on the CSR we should read the entire file, not just the first line and treat the entire content as a string in a specific encoding. While I wasn't able to get the JDK build a vendor name with new lines (due to jrt-fs.jar putting `COMPANYNAME` in the MANIFEST.MF) it's conceivable that some `release.txt` file might have more than one line.
>> 
>> Alternatively we need to specify that the file must not contain line breaks or unusual encodings.
>
> The proposal is to have a one line release signature set up by the build, briefly discussed the possibility to use a java properties file format as the current release file distributed with JDK, but then a simplified approach of one signature is preferred.
> 
> I'll update the PR once we come to conclusion with the CSR.

It might be useful to see what breaks if a JDK were built with a newline in the vendor name, I assume other things will break.

Overall I think the changes are looking good, the main thing is that the error message is clear.

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PR Review Comment: https://git.openjdk.org/jdk/pull/28155#discussion_r2550103816