Allow longer filenames to be uploaded to S3

src/main/java/com/upplication/s3fs/S3SeekableByteChannel.java

@@ -35,6 +35,7 @@ public S3SeekableByteChannel(S3Path path, Set<? extends OpenOption> options) thr
         this.path = path;
         this.options = Collections.unmodifiableSet(new HashSet<>(options));
         String key = path.getKey();
+        Path fileName = path.getFileName();
         boolean exists = path.getFileSystem().provider().exists(path);
 
         if (exists && this.options.contains(StandardOpenOption.CREATE_NEW))
@@ -43,7 +44,7 @@ else if (!exists && !this.options.contains(StandardOpenOption.CREATE_NEW) &&
                 !this.options.contains(StandardOpenOption.CREATE))
             throw new NoSuchFileException(format("target not exists: %s", path));
 
-        tempFile = Files.createTempFile("temp-s3-", key.replaceAll("/", "_"));
+        tempFile = Files.createTempFile("temp-s3-", fileName == null ? key : fileName.toString());
         boolean removeTempFile = true;
         try {
             if (exists) {

src/test/java/com/upplication/s3fs/S3SeekableByteChannelTest.java

@@ -98,4 +98,19 @@ public void tempFileDisappeared() throws IOException, NoSuchFieldException, Secu
         Files.delete(tempFile);
         channel.close();
     }
+
+    @Test
+    public void writeFileWithReallyLongName() throws IOException {
+        AmazonS3ClientMock client = AmazonS3MockFactory.getAmazonClientMock();
+        String longDirectoryName = "FuscetellusodiodapibusidfermentumquissuscipitideratEtiamquisquamVestibulumeratnullaullamcorpernecrutrumnonnon";
+        String longFileName = "ummyaceratSedutperspiciatisundeomnisisfasdfasdfasfsafdtenatuserrorsitvoluptatemaccusantiumdoloremquelaudantiumtotamremaperiameaqueipsaq";
+        client.bucket("buck").file(longDirectoryName + "/" + longFileName);
+
+        S3Path file1 = (S3Path) FileSystems.getFileSystem(S3EndpointConstant.S3_GLOBAL_URI_TEST).getPath("/buck/"+ longDirectoryName + "/" + longFileName);
+        S3SeekableByteChannel channel = spy(new S3SeekableByteChannel(file1, EnumSet.of(StandardOpenOption.WRITE)));
+        channel.write(ByteBuffer.wrap("hoi".getBytes()));
+        channel.close();
+
+        verify(channel, times(1)).sync();
+    }
 }