Fix: Custom filesystem exception for invalid ciphertext nodes

src/main/java/org/cryptomator/cryptofs/CryptoPathMapper.java

@@ -85,7 +85,8 @@ public void assertNonExisting(CryptoPath cleartextPath) throws FileAlreadyExists
 	/**
 	 * @param cleartextPath A path
 	 * @return The file type for the given path (if it exists)
-	 * @throws NoSuchFileException If no node exists at the given path for any known type
+	 * @throws NoSuchFileException If the ciphertext path does not exist
+	 * @throws InvalidFileNodeException If the node points to a ciphertext directory, which does not contain an identification file
 	 * @throws IOException
 	 */
 	public CiphertextFileType getCiphertextFileType(CryptoPath cleartextPath) throws NoSuchFileException, IOException {
@@ -105,7 +106,7 @@ public CiphertextFileType getCiphertextFileType(CryptoPath cleartextPath) throws
 				} else {
 					eventConsumer.accept(new BrokenFileNodeEvent(cleartextPath, ciphertextPath.getRawPath()));
 					LOG.warn("Did not find valid content inside of {}", ciphertextPath.getRawPath());
-					throw new NoSuchFileException(cleartextPath.toString(), null, "Could not determine type of file " + ciphertextPath.getRawPath());
+					throw new InvalidFileNodeException(cleartextPath.toString(), ciphertextPath.getRawPath().toString());
 				}
 			} else {
 				// assume "file" if not a directory (even if it isn't a "regular" file, see issue #81):
@@ -117,7 +118,7 @@ public CiphertextFileType getCiphertextFileType(CryptoPath cleartextPath) throws
 	public CiphertextFilePath getCiphertextFilePath(CryptoPath cleartextPath) throws IOException {
 		CryptoPath parentPath = cleartextPath.getParent();
 		if (parentPath == null) {
-			throw new IllegalArgumentException("Invalid file path (must have a parent): " + cleartextPath); //TODO: cleartext path in Logs!
+			throw new IllegalArgumentException("Invalid file path (must have a parent): " + cleartextPath);
 		}
 		CiphertextDirectory parent = getCiphertextDir(parentPath);
 		String cleartextName = cleartextPath.getFileName().toString();

src/main/java/org/cryptomator/cryptofs/InvalidFileNodeException.java

@@ -0,0 +1,13 @@
+package org.cryptomator.cryptofs;
+
+import java.nio.file.FileSystemException;
+
+/**
+ * Exception thrown if a c9s or c9r directory does not contain any identification files
+ */
+public class InvalidFileNodeException extends FileSystemException {
+
+	public InvalidFileNodeException(String cleartext, String ciphertext) {
+		super(cleartext, null, "Unknown type of node %s: Missing identification file".formatted(ciphertext));
+	}
+}

src/test/java/org/cryptomator/cryptofs/CryptoPathMapperTest.java

@@ -390,7 +390,7 @@ public void testDetectionPriority(boolean dirFileExists, boolean symlinkFileExis
 		}
 
 		@Test
-		@DisplayName("Throw NoSuchFileException if no known file exists")
+		@DisplayName("Throw a FileSystemException if no id file exists")
 		public void testNoKnownFileExists() throws IOException {
 			Mockito.when(underlyingFileSystemProvider.readAttributes(c9rPath, BasicFileAttributes.class, LinkOption.NOFOLLOW_LINKS)).thenReturn(c9rAttrs);
 			Mockito.when(c9rAttrs.isDirectory()).thenReturn(true);
@@ -404,7 +404,7 @@ public void testNoKnownFileExists() throws IOException {
 			CryptoPathMapper mapper = new CryptoPathMapper(pathToVault, cryptor, dirIdProvider, longFileNameProvider, vaultConfig, eventConsumer);
 
 			CryptoPath path = fileSystem.getPath("/CLEAR");
-			Assertions.assertThrows(NoSuchFileException.class, () -> mapper.getCiphertextFileType(path));
+			Assertions.assertThrows(InvalidFileNodeException.class, () -> mapper.getCiphertextFileType(path));
 			var isBrokenFileNodeEvent = (ArgumentMatcher<FilesystemEvent>) ev -> ev instanceof BrokenFileNodeEvent;
 			verify(eventConsumer).accept(ArgumentMatchers.argThat(isBrokenFileNodeEvent));
 		}