[YuqiGuo105]

Fixes #254.

Summary

Allow creating a regular file through a symbolic link whose target does not yet exist, without replacing the link.

The initial read-locked lookup already follows symbolic links, but the creation path unconditionally looked up the link with NOFOLLOW_LINKS and rejected it as "not a regular file". The current path resolver can already represent a missing target as a DirectoryEntry; no resolver changes are needed.

Changes

• Pass the appropriate link-following options into the write-locked creation lookup.
• Create the file using the resolved entry's parent and name, rather than the original link's name.
• Preserve CREATE_NEW, explicit NOFOLLOW_LINKS, directory creation and symbolic-link creation semantics.
• Add 11 public-API regression and compatibility tests covering relative/absolute targets, link chains, stream/channel APIs, initial permissions, missing parents and Windows cross-root targets.

No public API changes. Open-PR searches for the issue number and related keywords found no competing fix before submission.

Validation

macOS arm64, Temurin JDK 25.0.3, Maven 3.9.16; the project retains its Java 8 source/target configuration.

Before the production fix, the new Unix tests reported 10 tests, 5 errors, and the Windows test reported 1 test, 1 error, all six errors being FileSystemException: ... not a regular file:

mvn -B '-Dtest=JimfsUnixLikeFileSystemTest#*danglingSymbolicLink*' -Dsurefire.failIfNoSpecifiedTests=false test
mvn -B '-Dtest=JimfsWindowsLikeFileSystemTest#*danglingSymbolicLink*' -Dsurefire.failIfNoSpecifiedTests=false test

After the fix, all 11 targeted tests passed. Full verification was rerun before submission:

mvn -B clean verify

BUILD SUCCESS — 5,917 tests, 0 failures, 0 errors, 1 existing skipped test (JimfsFileChannelTest.testCloseByInterrupt). Packaging and Javadoc generation completed. Google Java Format 1.35.0 checks on the changed regions and git diff --check also passed.

AI assistance: OpenAI Codex assisted with implementation and local validation.

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