Don't run conflict resolver for files starting with .

fixes #73

Author: overheadhunter

src/main/java/org/cryptomator/cryptofs/dir/C9rConflictResolver.java

@@ -46,11 +46,17 @@ public C9rConflictResolver(Cryptor cryptor, @Named("dirId") String dirId) {
 	public Stream<Node> process(Node node) {
 		Preconditions.checkArgument(node.extractedCiphertext != null, "Can only resolve conflicts if extractedCiphertext is set");
 		Preconditions.checkArgument(node.cleartextName != null, "Can only resolve conflicts if cleartextName is set");
-
+		
 		String canonicalCiphertextFileName = node.extractedCiphertext + Constants.CRYPTOMATOR_FILE_SUFFIX;
 		if (node.fullCiphertextFileName.equals(canonicalCiphertextFileName)) {
+			// not a conflict:
 			return Stream.of(node);
+		} else if (node.fullCiphertextFileName.startsWith(".")) {
+			// ignore hidden files:
+			LOG.debug("Ignoring hidden file {}", node.ciphertextPath);
+			return Stream.empty();
 		} else {
+			// conflicting file:
 			try {
 				Path canonicalPath = node.ciphertextPath.resolveSibling(canonicalCiphertextFileName);
 				return resolveConflict(node, canonicalPath);

src/test/java/org/cryptomator/cryptofs/dir/C9rConflictResolverTest.java

@@ -6,6 +6,8 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.Mockito;
 
 import java.io.IOException;
@@ -33,13 +35,24 @@ public void testResolveNonConflictingNode() {
 		Node unresolved = new Node(Paths.get("foo.c9r"));
 		unresolved.cleartextName = "bar";
 		unresolved.extractedCiphertext = "foo";
-		
+
 		Stream<Node> result = conflictResolver.process(unresolved);
 		Node resolved = result.findAny().get();
 
 		Assertions.assertSame(unresolved, resolved);
 	}
 
+	@ParameterizedTest
+	@ValueSource(strings = {"._foo.c9r", ".foo.c9r"})
+	public void testResolveHiddenNode(String filename) {
+		Node unresolved = new Node(Paths.get(filename));
+		unresolved.cleartextName = "bar";
+		unresolved.extractedCiphertext = "foo";
+
+		Stream<Node> result = conflictResolver.process(unresolved);
+		Assertions.assertFalse(result.findAny().isPresent());
+	}
+
 	@Test
 	public void testResolveConflictingFileByChoosingNewName(@TempDir Path dir) throws IOException {
 		Files.createFile(dir.resolve("foo (1).c9r"));