Index: /trunk/src/org/openstreetmap/josm/gui/widgets/JosmTextField.java
===================================================================
--- /trunk/src/org/openstreetmap/josm/gui/widgets/JosmTextField.java	(revision 18537)
+++ /trunk/src/org/openstreetmap/josm/gui/widgets/JosmTextField.java	(revision 18538)
@@ -181,5 +181,5 @@
      */
     public String setHint(String hint) {
-        String old = hint;
+        String old = this.hint;
         this.hint = hint;
         return old;
Index: /trunk/test/unit/org/openstreetmap/josm/gui/widgets/JosmTextFieldTest.java
===================================================================
--- /trunk/test/unit/org/openstreetmap/josm/gui/widgets/JosmTextFieldTest.java	(revision 18538)
+++ /trunk/test/unit/org/openstreetmap/josm/gui/widgets/JosmTextFieldTest.java	(revision 18538)
@@ -0,0 +1,22 @@
+// License: GPL. For details, see LICENSE file.
+package org.openstreetmap.josm.gui.widgets;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+import org.openstreetmap.josm.testutils.annotations.BasicPreferences;
+
+/**
+ * Test class for {@link JosmTextField}
+ */
+@BasicPreferences
+class JosmTextFieldTest {
+    @Test
+    void testSetHint() {
+        JosmTextField josmTextField = new JosmTextField();
+        josmTextField.setHint("some hint");
+        assertEquals("some hint", josmTextField.getHint());
+        assertEquals("some hint", josmTextField.setHint("new hint"));
+        assertEquals("new hint", josmTextField.getHint());
+    }
+}