Bug 54116: Add test and fix for AbstractTreeViewer.expandToLevelI20190616-1800

AbstractTreeViewer.internalExpand always have to expand all parents, if
parameter expand is true

Change-Id: I29bb2f479ee1ba9af886443227fe96c6b72c82ab
Signed-off-by: Stephan Wahlbrink <sw@wahlbrink.eu>

2 files changed, 30 insertions, 12 deletions

diff --git a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
index ecc368ca87d..35cf6c8b6dc 100644
--- a/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
+++ b/bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
@@ -1679,21 +1679,23 @@ public abstract class AbstractTreeViewer extends ColumnViewer {
 					createChildren(pw);
 					Object element = internalToElement(elementOrPath);
 					w = internalFindChild(pw, element);
-					if (expand && pw instanceof Item) {
-						// expand parent items top-down
-						Item item = (Item) pw;
-						LinkedList<Item> toExpandList = new LinkedList<>();
-						while (item != null && !getExpanded(item)) {
-							toExpandList.addFirst(item);
-							item = getParentItem(item);
-						}
-						for (Item toExpand : toExpandList) {
-							setExpanded(toExpand, true);
-						}
-					}
 				}
 			}
 		}
+		if (expand && w instanceof Item) {
+			// expand parent items top-down
+			Item item = getParentItem((Item) w);
+			LinkedList<Item> toExpandList = new LinkedList<>();
+			while (item != null) {
+				if (!getExpanded(item)) {
+					toExpandList.addFirst(item);
+				}
+				item = getParentItem(item);
+			}
+			for (Item toExpand : toExpandList) {
+				setExpanded(toExpand, true);
+			}
+		}
 		return w;
 	}
 
diff --git a/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/AbstractTreeViewerTest.java b/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/AbstractTreeViewerTest.java
index 6a95029110a..089e64a3c6e 100644
--- a/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/AbstractTreeViewerTest.java
+++ b/tests/org.eclipse.ui.tests/Eclipse JFace Tests/org/eclipse/jface/tests/viewers/AbstractTreeViewerTest.java
@@ -118,6 +118,22 @@ public abstract class AbstractTreeViewerTest extends StructuredItemViewerTest {
 		assertNotNull("first2 is visible", fViewer.testFindItem(first2));
 	}
 
+	public void testExpandElementAgain() {
+		TestElement first = fRootElement.getFirstChild();
+		TestElement first2 = first.getFirstChild();
+		TestElement first3 = first2.getFirstChild();
+		fTreeViewer.expandToLevel(first3, 0);
+		assertTrue("first is expanded", fTreeViewer.getExpandedState(first));
+		assertTrue("first2 is expanded", fTreeViewer.getExpandedState(first2));
+		assertNotNull("first3 is visible", fViewer.testFindItem(first3));
+
+		fTreeViewer.setExpandedState(first, false);
+		fTreeViewer.expandToLevel(first3, 0);
+		assertTrue("first is expanded", fTreeViewer.getExpandedState(first)); // bug 54116
+		assertTrue("first2 is expanded", fTreeViewer.getExpandedState(first2));
+		assertNotNull("first3 is visible", fViewer.testFindItem(first3));
+	}
+
 	public void testExpandToLevel() {
 		TestElement first = fRootElement.getFirstChild();
 		TestElement first2 = first.getFirstChild();