Refactored multiple classes

Refactored UnlockWorkflow, CustomMountPointChooser, DokanyVolume and UnlockInvalidMountPointController

Changed UnlockWorkflow#handleGenericError() to accept Throwables

Added check for parent to CustomMountPointChooser (when using FUSE on Win)

Removed legacy constant from DokanyVolume

Added asserts to UnlockInvalidMountPointController and UnlockWorkflow

main/commons/src/main/java/org/cryptomator/common/mountpoint/CustomMountPointChooser.java

@@ -46,6 +46,10 @@ public class CustomMountPointChooser implements MountPointChooser {
 			//This the case on Windows when using FUSE
 			//See https://github.com/billziss-gh/winfsp/issues/320
 
+			Path parent = mountPoint.getParent();
+			if (!Files.isDirectory(parent)) {
+				throw wrapAsIMPE(new NotDirectoryException(parent.toString()));
+			}
 			//We must use #notExists() here because notExists =/= !exists (see docs)
 			if (!Files.notExists(mountPoint, LinkOption.NOFOLLOW_LINKS)) {
 				//File exists OR can't be determined

main/commons/src/main/java/org/cryptomator/common/vaults/DokanyVolume.java

@@ -22,7 +22,6 @@ import java.util.concurrent.ExecutorService;
 public class DokanyVolume implements Volume {
 
 	private static final Logger LOG = LoggerFactory.getLogger(DokanyVolume.class);
-	private static final int MAX_TMPMOUNTPOINT_CREATION_RETRIES = 10;
 
 	private static final String FS_TYPE_NAME = "Cryptomator File System";
 

main/ui/src/main/java/org/cryptomator/ui/unlock/UnlockInvalidMountPointController.java

@@ -40,6 +40,7 @@ public class UnlockInvalidMountPointController implements FxController {
 	public boolean getMustExist() {
 		MountPointRequirement requirement = vault.getMountPointRequirement();
 		assert requirement != MountPointRequirement.NONE; //An invalid MountPoint with no required MountPoint doesn't seem sensible
+		assert requirement != MountPointRequirement.PARENT_OPT_MOUNT_POINT; //Not implemented anywhere (yet)
 
 		return requirement == MountPointRequirement.EMPTY_MOUNT_POINT;
 	}

main/ui/src/main/java/org/cryptomator/ui/unlock/UnlockWorkflow.java

@@ -162,6 +162,7 @@ public class UnlockWorkflow extends Task<Boolean> {
 	private void handleInvalidMountPoint(InvalidMountPointException e) {
 		MountPointRequirement requirement = vault.getMountPointRequirement();
 		assert requirement != MountPointRequirement.NONE; //An invalid MountPoint with no required MountPoint doesn't seem sensible
+		assert requirement != MountPointRequirement.PARENT_OPT_MOUNT_POINT; //Not implemented anywhere (yet)
 
 		if (requirement == MountPointRequirement.EMPTY_MOUNT_POINT) {
 			LOG.error("Unlock failed. Mount point not an empty directory or doesn't exist: {}", e.getMessage());
@@ -174,7 +175,7 @@ public class UnlockWorkflow extends Task<Boolean> {
 		});
 	}
 
-	private void handleGenericError(Exception e) {
+	private void handleGenericError(Throwable e) {
 		LOG.error("Unlock failed for technical reasons.", e);
 		Platform.runLater(() -> {
 			errorComponent.cause(e).window(window).returnToScene(window.getScene()).build().showErrorScene();