Fixed bug in SFTP FileMode for AIX/Unix directory mask

src/main/java/net/schmizz/sshj/sftp/FileMode.java

@@ -74,7 +74,7 @@ public class FileMode {
     }
 
     public int getTypeMask() {
-        return mask & 0770000;
+        return mask & 0170000;
     }
 
     public int getPermissionsMask() {

src/test/java/net/schmizz/sshj/sftp/FileModeTest.java

@@ -0,0 +1,23 @@
+package net.schmizz.sshj.sftp;
+
+import org.junit.Test;
+
+import static org.hamcrest.core.IsEqual.equalTo;
+import static org.junit.Assert.assertThat;
+
+public class FileModeTest {
+
+	@Test
+	public void shouldDetectDirectoryWithLinuxMask() {
+		FileMode fileMode = new FileMode(040755);
+		assertThat(fileMode.toString(), equalTo("[mask=40755]"));
+		assertThat(fileMode.getType(), equalTo(FileMode.Type.DIRECTORY));
+	}
+
+	@Test
+	public void shouldDetectDirectoryWithAixUnixMask() {
+		FileMode fileMode = new FileMode(0240755);
+		assertThat(fileMode.toString(), equalTo("[mask=240755]"));
+		assertThat(fileMode.getType(), equalTo(FileMode.Type.DIRECTORY));
+	}
+}