Clear history view when repository has been removed

After removing a repository that was shown in the history view, it's
data was still shown and clicking on a commit and/ or file led to
NPEs.

Bug: 332934
Change-Id: Ia1fcb56aa1622e1191dbb823ce26aa3a643f526d
Signed-off-by: Philipp Thun <philipp.thun@sap.com>

2 files changed, 33 insertions, 1 deletions

diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
index a72b7d237c..cb4f653b30 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/GitHistoryPage.java
@@ -807,15 +807,35 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener {
 
 	@Override
 	public void setFocus() {
+		if (repoHasBeenRemoved(currentRepo))
+			clearHistoryPage();
+
 		graph.getControl().setFocus();
 	}
 
+	private boolean repoHasBeenRemoved(final Repository repo) {
+		return (repo != null && repo.getDirectory() != null && !repo
+				.getDirectory().exists());
+	}
+
+	private void clearHistoryPage() {
+		currentRepo = null;
+		name = ""; //$NON-NLS-1$
+		input = null;
+		commentViewer.setInput(null);
+		fileViewer.setInput(null);
+		setInput(null);
+	}
+
 	@Override
 	public Control getControl() {
 		return topControl;
 	}
 
 	public void refresh() {
+		if (repoHasBeenRemoved(currentRepo))
+			clearHistoryPage();
+
 		this.input = null;
 		inputSet();
 	}
@@ -1257,8 +1277,18 @@ public class GitHistoryPage extends HistoryPage implements RefsChangedListener {
 						GitTraceLocation.HISTORYVIEW.getLocation());
 
 			cancelRefreshJob();
+
+			if (input == null)
+				return;
 			Repository db = input.getRepository();
-			AnyObjectId headId = resolveHead(db, false);
+			if (repoHasBeenRemoved(db)) {
+				clearHistoryPage();
+				return;
+			}
+
+			AnyObjectId headId = resolveHead(db, true);
+			if (headId == null)
+				return;
 
 			List<String> paths = buildFilterPaths(input.getItems(), input
 					.getFileList(), db);
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/AbstractHistoryCommandHandler.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/AbstractHistoryCommandHandler.java
index 55addf0002..b95e1b7991 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/AbstractHistoryCommandHandler.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/history/command/AbstractHistoryCommandHandler.java
@@ -74,6 +74,8 @@ abstract class AbstractHistoryCommandHandler extends AbstractHandler {
 	protected Repository getRepository(ExecutionEvent event)
 			throws ExecutionException {
 		Object input = getInput(event);
+		if (input == null)
+			return null;
 		if (input instanceof HistoryPageInput)
 			return ((HistoryPageInput) input).getRepository();
 		if (input instanceof RepositoryTreeNode)