Maven build dir can now be a softlink (#1859 fixes #1858)

Author: nedtwigg

plugin-maven/CHANGES.md

@@ -3,11 +3,12 @@
 We adhere to the [keepachangelog](https://keepachangelog.com/en/1.0.0/) format (starting after version `1.27.0`).
 
 ## [Unreleased]
-### Changes
-* Bump default `ktlint` version to latest `1.0.0` -> `1.0.1`. ([#1855](https://github.com/diffplug/spotless/pull/1855))
-
 ### Added
 * CompileSourceRoots and TestCompileSourceRoots are now respected as default includes. These properties are commonly set when adding extra source directories. ([#1846](https://github.com/diffplug/spotless/issues/1846))
+### Fixed
+* Fix crash when build dir is a softlink to another directory. ([#1859](https://github.com/diffplug/spotless/pull/1859))
+### Changes
+* Bump default `ktlint` version to latest `1.0.0` -> `1.0.1`. ([#1855](https://github.com/diffplug/spotless/pull/1855))
 
 ## [2.40.0] - 2023-09-28
 ### Added

plugin-maven/src/main/java/com/diffplug/spotless/maven/incremental/FileIndex.java

@@ -26,6 +26,7 @@
 import java.io.PrintWriter;
 import java.io.UncheckedIOException;
 import java.nio.file.Files;
+import java.nio.file.LinkOption;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.time.Instant;
@@ -144,7 +145,14 @@ private void ensureParentDirExists() {
 			throw new IllegalStateException("Index file does not have a parent dir: " + indexFile);
 		}
 		try {
-			Files.createDirectories(parentDir);
+			if (Files.exists(parentDir, LinkOption.NOFOLLOW_LINKS)) {
+				Path realPath = parentDir.toRealPath();
+				if (!Files.exists(realPath)) {
+					Files.createDirectories(realPath);
+				}
+			} else {
+				Files.createDirectories(parentDir);
+			}
 		} catch (IOException e) {
 			throw new UncheckedIOException("Unable to create parent directory for the index file: " + indexFile, e);
 		}