Do not try to create children for Show node in search view.

Navigate feature of SearchView tries to create children for element for
Show node.
We should not support expanded state for ExpandableNode.

Fixes eclipse-platform#1024

bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java

@@ -2596,6 +2596,12 @@ public void setExpandedState(Object elementOrTreePath, boolean expanded) {
 		Assert.isNotNull(elementOrTreePath);
 		if (checkBusy())
 			return;
+
+		// we do not support expand/collapse for ExpandableNode
+		if (isExpandableNode(elementOrTreePath)) {
+			return;
+		}
+
 		Widget item = internalExpand(elementOrTreePath, false);
 		if (item instanceof Item) {
 			if (expanded) {

bundles/org.eclipse.search/new search/org/eclipse/search2/internal/ui/basic/views/TreeViewerNavigator.java

@@ -108,6 +108,10 @@ private TreeItem getNextItemForward(TreeItem currentItem) {
 			return child;
 		TreeItem nextSibling= getNextSibling(currentItem, true);
 		if (nextSibling != null) {
+			// do not search for matches inside exp node. just select it.
+			if (fViewer.isExpandableNode(nextSibling.getData())) {
+				return nextSibling;
+			}
 			if (hasMatches(nextSibling))
 				return nextSibling;
 			return getFirstChildWithMatches(nextSibling);
@@ -116,6 +120,10 @@ private TreeItem getNextItemForward(TreeItem currentItem) {
 		while (parent != null) {
 			nextSibling= getNextSibling(parent, true);
 			if (nextSibling != null) {
+				// if the parent sibling is an exp node then select it.
+				if (fViewer.isExpandableNode(nextSibling.getData())) {
+					return nextSibling;
+				}
 				if (hasMatches(nextSibling))
 					return nextSibling;
 				return getFirstChildWithMatches(nextSibling);