check existence of alternativeName file to not overwrite data

Author: infeo

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

@@ -14,7 +14,6 @@
 import javax.inject.Named;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
-import java.nio.file.FileAlreadyExistsException;
 import java.nio.file.Files;
 import java.nio.file.NoSuchFileException;
 import java.nio.file.Path;
@@ -123,18 +122,17 @@ private Stream<Node> renameConflictingFile(Path canonicalPath, Node conflicting)
 		}
 
 		assert alternativeCiphertextName.length() <= maxC9rFileNameLength;
-		try {
-			Files.move(conflicting.ciphertextPath, alternativePath, StandardCopyOption.ATOMIC_MOVE);
-			LOG.info("Renamed conflicting file {} to {}...", conflicting.ciphertextPath, alternativePath);
-			Node node = new Node(alternativePath);
-			node.cleartextName = alternativeCleartext;
-			node.extractedCiphertext = alternativeCiphertext;
-			return Stream.of(node);
-		} catch (FileAlreadyExistsException e) {
-			// TODO notify user about unresolved conflict: `canonicalPath`
-			LOG.warn("Failed to rename conflicting file {} to {}. Keeping original name.", conflicting.ciphertextPath, alternativePath);
+		if (Files.exists(alternativePath)) {
+			LOG.warn("Failed finding alternative name for {}. Keeping original name.", conflicting.ciphertextPath);
 			return Stream.empty();
 		}
+
+		Files.move(conflicting.ciphertextPath, alternativePath, StandardCopyOption.ATOMIC_MOVE);
+		LOG.info("Renamed conflicting file {} to {}...", conflicting.ciphertextPath, alternativePath);
+		Node node = new Node(alternativePath);
+		node.cleartextName = alternativeCleartext;
+		node.extractedCiphertext = alternativeCiphertext;
+		return Stream.of(node);
 	}
 
 

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

@@ -8,7 +8,6 @@
 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.CsvSource;
 import org.junit.jupiter.params.provider.ValueSource;
 import org.mockito.Mockito;
 
@@ -116,6 +115,22 @@ public void testResolveConflictingFileByChoosingNewLengthLimitedName(@TempDir Pa
 		Assertions.assertFalse(Files.exists(unresolved.ciphertextPath));
 	}
 
+	@Test
+	public void testResolveConflictFailedAlternativeNamesReserved(@TempDir Path dir) throws IOException {
+		Files.createFile(dir.resolve("foo (Created by Alice on 2024-01-31).c9r"));
+		Files.createFile(dir.resolve("foo.c9r"));
+		Files.createFile(dir.resolve("baz.c9r"));
+		Mockito.when(fileNameCryptor.encryptFilename(Mockito.any(), Mockito.any(), Mockito.any())).thenReturn("baz");
+		Node unresolved = new Node(dir.resolve("foo (Created by Alice on 2024-01-31).c9r"));
+		unresolved.cleartextName = "this is a rather long file name.txt";
+		unresolved.extractedCiphertext = "foo";
+
+		Stream<Node> result = conflictResolver.process(unresolved);
+		Assertions.assertTrue(result.findAny().isEmpty());
+		Assertions.assertTrue(Files.exists(unresolved.ciphertextPath));
+		Mockito.verify(fileNameCryptor, Mockito.times(10)).encryptFilename(Mockito.any(), Mockito.any(), Mockito.any());
+	}
+
 	@Test
 	public void testResolveConflictingFileTrivially(@TempDir Path dir) throws IOException {
 		Files.createFile(dir.resolve("foo (1).c9r"));