FileTreeElement.getPath() returns absolute system dependent filepath

[Larusso]

With Gradle 4.10 the result of FileTreeElement.getPath() changed in a breaking way.

Expected Behavior

From the method documentation:

Returns the path of this file, relative to the root of the containing file tree. Always uses '/' as the hierarchy separator, regardless of platform file separator. Same as calling getRelativePath().getPathString().

The expected String path should be relative to the FileTree and use / as file seperators even on windows environments.

Current Behavior

With Gradle 4.10 this changed. The resulting String is an absolute system dependent path.

Context

In my plugin I provide a default FileCollection which is constructed with the help of PatternFilterable include(Spec<FileTreeElement> includeSpec); API.
In my Spec<FileTreeElement> implementation I retrieve the file path with `element.getPath() and do some checks based on the asumption that it is relative and normalized.

In gradle <= 4.9 the FileTreeElement was implemented as a DefaultFileVisitDetails which calls getRelativePath().getPathString(); as advertised in the docs.
As of gradle 4.10 some elements are implemented as PathBackedFileTreeElement which implements getPath() as follows:

gradle/subprojects/core/src/main/java/org/gradle/internal/snapshot/impl/DirectorySnapshotter.java

Lines 304 to 307 in f3079d7

	@Override
	public String getPath() {
	return path.toString();
	}

Steps to Reproduce (for bugs)

https://github.com/wooga/atlas-build-unity in branch gradle/issue_6656

running the test specs from UnityBuildPlayerTaskIntegrationSpec will work from gradle version 3.5 - 4.9 and start to fail on 4.10.

Your Environment

I can verify this issue both on macOS and windows systems.

[wolfs]

@Larusso Thank you for the report! That really seems to be a problem and we will fix it for 4.10.1.

I cannot reproduce the test failure for your project. I have been running:

GRADLE_VERSION=4.10 ./gradlew integrationTest --tests="*UnityBuildPlayerTaskIntegrationSpec*"

See https://scans.gradle.com/s/d5lyvljx62jke/tests

[Larusso]

Ah sorry I already fixed it with the last commit by using ‘getRelativePath().getPathString();’ instead. I could push a branch without the patch if needed.

[Larusso]

I pushed a branch (gradle/issue_6656) to replicate the issue.

GRADLE_VERSION=4.9 ./gradlew integrationTest --tests="*UnityBuildPlayerTaskIntegrationSpec*" works

GRADLE_VERSION=4.10 ./gradlew integrationTest --tests="*UnityBuildPlayerTaskIntegrationSpec*" fails

[wolfs]

Fixed via #6667.