Try to port MCLEAN-93: Windows NTFS junctions support.

Author: desruisseaux

src/main/java/org/apache/maven/plugins/clean/Cleaner.java

@@ -49,7 +49,9 @@
  * @author Martin Desruisseaux
  */
 final class Cleaner implements FileVisitor<Path> {
-
+    /**
+     * Whether the host operating system is from the Windows family.
+     */
     private static final boolean ON_WINDOWS = (File.separatorChar == '\\');
 
     private static final SessionData.Key<Path> LAST_DIRECTORY_TO_DELETE =
@@ -193,7 +195,7 @@ public void delete(Path basedir) throws IOException {
         var options = EnumSet.noneOf(FileVisitOption.class);
         if (followSymlinks) {
             options.add(FileVisitOption.FOLLOW_LINKS);
-            basedir = getCanonicalPath(basedir);
+            basedir = getCanonicalPath(basedir, null);
         }
         if (selector == null && !followSymlinks && fastDir != null && session != null) {
             // If anything wrong happens, we'll just use the usual deletion mechanism
@@ -275,12 +277,21 @@ public FileVisitResult preVisitDirectory(Path dir, BasicFileAttributes attrs) th
      */
     @Override
     public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {
-        if ((selector == null || selector.matches(file)) && tryDelete(file)) {
-            if (listDeletedFiles) {
-                logDelete(file, attrs);
-            }
+        if (ON_WINDOWS && followSymlinks && attrs.isDirectory() && attrs.isOther()) {
+            /*
+             * MCLEAN-93: NTFS junctions have isDirectory() and isOther() attributes set.
+             * Handle as a directory walked by a new `FileVisitor`.
+             */
+            file = getCanonicalPath(file, null);
+            Files.walkFileTree(file, EnumSet.of(FileVisitOption.FOLLOW_LINKS), Integer.MAX_VALUE, this);
         } else {
-            nonEmptyDirectoryLevels.set(currentDepth); // Remember that the directory will not be empty.
+            if ((selector == null || selector.matches(file)) && tryDelete(file)) {
+                if (listDeletedFiles) {
+                    logDelete(file, attrs);
+                }
+            } else {
+                nonEmptyDirectoryLevels.set(currentDepth); // Remember that the directory will not be empty.
+            }
         }
         return FileVisitResult.CONTINUE;
     }
@@ -333,11 +344,30 @@ public FileVisitResult postVisitDirectory(Path dir, IOException failure) throws
         return FileVisitResult.CONTINUE;
     }
 
-    private static Path getCanonicalPath(Path path) {
+    /**
+     * Returns the real path of the given file. If the real path cannot be obtained,
+     * this method tries to get the real path of the parent and to append the rest of
+     * the filename.
+     *
+     * @param  path       the path to get as a canonical path
+     * @param  mainError  should be {@code null} (reserved to recursive calls of this method)
+     * @return the real path of the given path
+     * @throws IOException if the canonical path cannot be obtained
+     */
+    private static Path getCanonicalPath(final Path path, IOException mainError) throws IOException {
         try {
             return path.toRealPath();
         } catch (IOException e) {
-            return getCanonicalPath(path.getParent()).resolve(path.getFileName());
+            if (mainError == null) {
+                mainError = e;
+            } else {
+                mainError.addSuppressed(e);
+            }
+            final Path parent = path.getParent();
+            if (parent != null) {
+                return getCanonicalPath(parent, mainError).resolve(path.getFileName());
+            }
+            throw e;
         }
     }