8381670: Revert the changes to GZIPInputStream related to InputStream.available() usage

[rm-gh-8]

Backporting JDK-8381670: Revert the changes to GZIPInputStream related to InputStream.available() usage.

This PR reverts changes from JDK-7036144, that caused both a performance regression (JDK-8374644) and a functional regression (JDK-8377896)

Ran related tests on linux-x64, linux-aarch64, macos-aarch64 and windows-x64:

make test TEST=test/jdk/java/util/zip/GZIP

Results attached:

windows-x64-specific-test.log
macos-aarch64-specific-test.log
linux-x64-specific-test.log
linux-aarch64-specific-test.log

---

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Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8381670 needs maintainer approval
• Change requires CSR request JDK-8381671 to be approved

Issues

• JDK-8381670: Revert the changes to GZIPInputStream related to InputStream.available() usage (Bug - P3 - Requested)
• JDK-8381671: Revert the changes to GZIPInputStream related to InputStream.available() usage (CSR)

Reviewing

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[openjdk]

This backport pull request has now been updated with issue from the original commit.

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[rm-gh-8]

/approval request for backport of JDK-8381670: Revert the changes to GZIPInputStream related to InputStream.available() usage.

This PR reverts changes from JDK-7036144, that caused both a performance regression (JDK-8374644) and a functional regression (JDK-8377896)

Low risk — this is a rollback to behavior that was stable for decades.

[openjdk]

@rm-gh-8
8381670: The approval request has been created successfully.

[rm-gh-8]

@GoeLin Please note that this has been merged in jdk26u (openjdk/jdk26u#165)

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[rm-gh-8]

@GoeLin Please note that this was backported to the Oracle JDK: https://bugs.openjdk.org/browse/JDK-8385365

[simonis]

@GoeLin Please note that this was backported to the Oracle JDK: https://bugs.openjdk.org/browse/JDK-8385365

While that is technically correct, that downport happened before the lengthy discussion on openjdk/jdk#30925 (comment). Oracle is now about to re-integrate those changes which were backed out, but this time guarded by a new system property, such that users can choose between the old and the new behavior.

I suggest we wait until that change (i.e. JDK-8385924: GZIPInputStream.read() behaves differently on some Java versions) lands in JDK 27 and then downport both, this change (i.e. JDK-8381670) and JDK-8385924 simultaneously to JDK 25u. This will make it possible to maintain the original JDK 25 behavior while at the same time give users a chance to switch back to the before JDK 25 behavior with a system property.

[GoeLin]

Hi @simonis @rm-gh-8
yes, I also think that as we are now targeting the October release there is enough time to await what happens in head.