Add test to Combo

Checks existing behavior

Author: fedejeanne

tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_widgets_Combo.java

@@ -23,6 +23,8 @@
 import static org.junit.Assert.fail;
 import static org.junit.Assume.assumeTrue;
 
+import java.util.concurrent.atomic.AtomicInteger;
+
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.ModifyListener;
 import org.eclipse.swt.events.SegmentListener;
@@ -383,6 +385,19 @@ public void test_getSelectionIndex() {
 	}
 }
 
+@Test
+public void test_getSelectionIndex_duringSelect() {
+	final AtomicInteger duringModification = new AtomicInteger(-2);
+	combo.add("abc");
+	combo.addListener(SWT.Modify, evt -> {
+		duringModification.set(combo.getSelectionIndex());
+	});
+
+	combo.select(0);
+
+	assertEquals(0, duringModification.get());
+}
+
 @Test
 public void test_getText() {
 	String[] cases = {"", "fred", "fredfred"};