Fix lock workflow for webdav:

* internally, wait for condition that onExit-Method is exceuted (with timeout)
* store and execute onExitAction also for webdav

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

@@ -42,7 +42,11 @@ import java.util.EnumSet;
 import java.util.Objects;
 import java.util.Optional;
 import java.util.Set;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReentrantLock;
 
 import static org.cryptomator.common.Constants.MASTERKEY_FILENAME;
 
@@ -70,6 +74,8 @@ public class Vault {
 	private final StringBinding accessPoint;
 	private final BooleanBinding accessPointPresent;
 	private final BooleanProperty showingStats;
+	private final Lock lock = new ReentrantLock(); //FIXME: naming
+	private final Condition isLocked = lock.newCondition(); //FIXME: improve naming
 
 	private volatile Volume volume;
 
@@ -146,6 +152,13 @@ public class Vault {
 					if (throwable != null) {
 						LOG.warn("Unexpected unmount and lock of vault " + getDisplayName(), throwable);
 					}
+					lock.lock();
+					try {
+						isLocked.signal();
+					} finally {
+						lock.unlock();
+					}
+
 				});
 			} catch (Exception e) {
 				destroyCryptoFileSystem();
@@ -163,6 +176,20 @@ public class Vault {
 			volume.unmount();
 		}
 		destroyCryptoFileSystem();
+		lock.lock();
+		try {
+			while (state.get() != VaultState.Value.LOCKED) {
+				if (!isLocked.await(3000, TimeUnit.MILLISECONDS)) {
+					throw new VolumeException("Locking failed"); //FIXME: other exception
+				}
+			}
+		} catch (InterruptedException e) {
+			Thread.currentThread().interrupt();
+			throw new VolumeException("Lock failed."); //FIXME: other/new exception
+		} finally {
+			lock.unlock();
+		}
+
 	}
 
 	public void reveal(Volume.Revealer vaultRevealer) throws VolumeException {

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

@@ -17,8 +17,6 @@ import java.net.InetAddress;
 import java.net.UnknownHostException;
 import java.nio.file.Path;
 import java.util.Optional;
-import java.util.concurrent.CompletableFuture;
-import java.util.concurrent.CompletionStage;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
 
@@ -34,6 +32,7 @@ public class WebDavVolume implements Volume {
 	private WebDavServer server;
 	private WebDavServletController servlet;
 	private Mounter.Mount mount;
+	private Consumer<Throwable> onExitAction;
 
 	@Inject
 	public WebDavVolume(Provider<WebDavServer> serverProvider, VaultSettings vaultSettings, Settings settings, WindowsDriveLetters windowsDriveLetters) {
@@ -47,9 +46,10 @@ public class WebDavVolume implements Volume {
 	public void mount(CryptoFileSystem fs, String mountFlags, Consumer<Throwable> onExitAction) throws VolumeException {
 		startServlet(fs);
 		mountServlet();
+		this.onExitAction = onExitAction;
 	}
 
-	private void startServlet(CryptoFileSystem fs){
+	private void startServlet(CryptoFileSystem fs) {
 		if (server == null) {
 			server = serverProvider.get();
 		}
@@ -69,7 +69,7 @@ public class WebDavVolume implements Volume {
 
 		//on windows, prevent an automatic drive letter selection in the upstream library. Either we choose already a specifc one or there is no free.
 		Supplier<String> driveLetterSupplier;
-		if(System.getProperty("os.name").toLowerCase().contains("windows") && vaultSettings.winDriveLetter().isEmpty().get()) {
+		if (System.getProperty("os.name").toLowerCase().contains("windows") && vaultSettings.winDriveLetter().isEmpty().get()) {
 			driveLetterSupplier = () -> windowsDriveLetters.getAvailableDriveLetter().orElse(null);
 		} else {
 			driveLetterSupplier = () -> vaultSettings.winDriveLetter().get();
@@ -104,6 +104,7 @@ public class WebDavVolume implements Volume {
 			throw new VolumeException(e);
 		}
 		cleanup();
+		onExitAction.accept(null);
 	}
 
 	@Override
@@ -114,6 +115,7 @@ public class WebDavVolume implements Volume {
 			throw new VolumeException(e);
 		}
 		cleanup();
+		onExitAction.accept(null);
 	}
 
 	@Override

main/ui/src/main/java/org/cryptomator/ui/lock/LockWorkflow.java

@@ -83,7 +83,7 @@ public class LockWorkflow extends Task<Void> {
 	@Override
 	protected void succeeded() {
 		LOG.info("Lock of {} succeeded.", vault.getDisplayName());
-		//DO NOT SET VAULT STATE HERE, this is done by the vault internally
+		vault.stateProperty().transition(VaultState.Value.PROCESSING, VaultState.Value.LOCKED);
 	}
 
 	@Override