Do not decode plain hostname (#337)

Author: gesellix

src/main/java/de/gesellix/docker/client/filesocket/FileSocket.java

@@ -13,6 +13,9 @@ public String encodeHostname(String hostname) {
 
   public String decodeHostname(InetAddress address) {
     String hostName = address.getHostName();
+    if (!hostName.endsWith(SOCKET_MARKER)) {
+      return hostName;
+    }
     return new HostnameEncoder().decode(hostName.substring(0, hostName.indexOf(SOCKET_MARKER)));
   }
 }

src/test/java/de/gesellix/docker/client/filesocket/FileSocketTest.java

@@ -0,0 +1,41 @@
+package de.gesellix.docker.client.filesocket;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import java.net.InetAddress;
+
+import org.junit.jupiter.api.Test;
+
+class FileSocketTest {
+
+  @Test
+  public void shouldEncodeHostname() throws Exception {
+    final String plainHostname = "for.test";
+    try (TestSocket testSocket = new TestSocket()) {
+      String encodedHostname = testSocket.encodeHostname(plainHostname);
+      assertEquals("666f722e74657374.socket", encodedHostname);
+    }
+  }
+
+  @Test
+  public void shouldDecodeEncodedHostname() throws Exception {
+    final String encodedHostname = "666f722e74657374.socket";
+    try (TestSocket testSocket = new TestSocket()) {
+      String decodedHostname = testSocket.decodeHostname(InetAddress.getByAddress(encodedHostname, new byte[]{0, 0, 0, 1}));
+      assertEquals("for.test", decodedHostname);
+    }
+  }
+
+  @Test
+  public void shouldNotDecodePlainHostname() throws Exception {
+    final String plainHostname = "for.test";
+    try (TestSocket testSocket = new TestSocket()) {
+      String decodedHostname = testSocket.decodeHostname(InetAddress.getByAddress(plainHostname, new byte[]{0, 0, 0, 1}));
+      assertEquals(plainHostname, decodedHostname);
+    }
+  }
+
+  static class TestSocket extends FileSocket {
+  }
+
+}