8331485: Odd Results when Parsing Scientific Notation with Large Exponent

[rm-gh-8]

Backporting JDK-8331485: Odd Results when Parsing Scientific Notation with Large Exponent.

Problem: DecimalFormat incorrectly parses strings with very large exponents:

• Exponents > Integer.MAX_VALUE return 0.0
• Exponents > Long.MAX_VALUE return the mantissa value

Fix: DecimalFormat.parse() now returns Double.POSITIVE_INFINITY for very large exponents, matching Double.parseDouble() behavior.

Impact: Eliminates edge case bug and provides consistent parsing behavior across Java's number parsing APIs.

Ran GHA Sanity Checks (passed) and related test (passed).

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8331485 needs maintainer approval
• JDK-8331680 needs maintainer approval

Issues

• JDK-8331485: Odd Results when Parsing Scientific Notation with Large Exponent (Bug - P4)
• JDK-8331680: NumberFormat is missing some bad exponent strict parse cases (Bug - P4)

Reviewing

Using git

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$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/2481/head:pull/2481
$ git checkout pull/2481

Update a local copy of the PR:
$ git checkout pull/2481
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/2481/head

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$ git pr checkout 2481

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https://git.openjdk.org/jdk21u-dev/pull/2481.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

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[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

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

[mlbridge]

Webrevs

• 01: Full - Incremental (d8d611af)
• 00: Full (3595aa07)

[phohensee]

This has the same problem with LenientParseTest.java as #2468. StrictParseTest.java has the same issue.

[rm-gh-8]

Removed LenientParseTest.java. Tests already available in "LargeExponentsTest.java".