[Win32] Fix deletion of read-only files not working with Java 25 #2178

With Java 25, the behavior of File#delete() has been changed for
read-only files on Windows. Previously, the operation also removed
read-only files whereas now the operation fails in that case.
LocalFile#delete() depends on the preexisting behavior. It ensures that
read-only files are also deleted.

In order to preserve the behavior with Java 25, this change makes
LocalFile#delete() explicitly remove the read-only attribute when
deleting a read-only file on WIndows.

Fixes #2178

Author: HeikoKlare

resources/bundles/org.eclipse.core.filesystem/src/org/eclipse/core/internal/filesystem/local/LocalFile.java

@@ -61,6 +61,7 @@
 import org.eclipse.core.runtime.MultiStatus;
 import org.eclipse.core.runtime.NullProgressMonitor;
 import org.eclipse.core.runtime.OperationCanceledException;
+import org.eclipse.core.runtime.Platform.OS;
 import org.eclipse.core.runtime.Status;
 import org.eclipse.core.runtime.SubMonitor;
 import org.eclipse.osgi.util.NLS;
@@ -314,6 +315,12 @@ private IStatus internalDelete(File target, InfiniteProgress infMonitor, Executo
 			} catch (AccessDeniedException e) {
 				// If the file is read only, it can't be deleted via Files.deleteIfExists()
 				// see https://bugs.eclipse.org/bugs/show_bug.cgi?id=500306
+				// Since Java 25, just calling File#delete() is not sufficient anymore on Windows
+				// but the read-only state has to be cleared explicitly,
+				// see https://bugs.openjdk.org/browse/JDK-8355954
+				if (OS.isWindows()) {
+					target.setWritable(true);
+				}
 				if (target.delete()) {
 					infMonitor.worked();
 					return Status.OK_STATUS;