Fix various exceptions in ImportProjectsCommand

It is possible to get NullPointerException,
ArrayIndexOutOfBoundsException and ClassCastException when the command
is invoked in a way the author did not anticipate.

Bug: 398933
Change-Id: I729e1dea45b9f452cf9902e13c63b4de3f741e00

5 files changed, 37 insertions, 2 deletions

diff --git a/org.eclipse.egit.ui/plugin.properties b/org.eclipse.egit.ui/plugin.properties
index 3f21551327..2e58471136 100644
--- a/org.eclipse.egit.ui/plugin.properties
+++ b/org.eclipse.egit.ui/plugin.properties
@@ -135,6 +135,7 @@ PushCommand = Push...
 RefreshCommand = Refresh
 RemoveRepositoryCommand = Remove Repository
 ImportProjectsCommand = Import Projects...
+ImportProjectsCommand_description = Import or create in local Git repository
 CreateBranchCommand = Create Branch...
 NewRemoteCommand = Create Remote...
 ConfigureFetchCommand = Configure Fetch...
diff --git a/org.eclipse.egit.ui/plugin.xml b/org.eclipse.egit.ui/plugin.xml
index b54273fe4d..5331ea55a6 100644
--- a/org.eclipse.egit.ui/plugin.xml
+++ b/org.eclipse.egit.ui/plugin.xml
@@ -3987,7 +3987,9 @@
             categoryId="org.eclipse.egit.ui.commandCategory"
             defaultHandler="org.eclipse.egit.ui.internal.repository.tree.command.ImportProjectsCommand"
             id="org.eclipse.egit.ui.RepositoriesViewImportProjects"
-            name="%ImportProjectsCommand">
+            name="%ImportProjectsCommand"
+            description="%ImportProjectsCommand_description"
+            >
       </command>
       <command
             categoryId="org.eclipse.egit.ui.commandCategory"
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
index b20f5aeaf8..2c9a6bb557 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/UIText.java
@@ -3856,6 +3856,12 @@ public class UIText extends NLS {
 	public static String GitTraceConfigurationDialog_TraceFileLocationLabel;
 
 	/** */
+	public static String ImportProjectsWrongSelection;
+
+	/** */
+	public static String ImportProjectsSelectionInRepositoryRequired;
+
+	/** */
 	public static String LocalFileRevision_CurrentVersion;
 
 	/** */
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/repository/tree/command/ImportProjectsCommand.java b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/repository/tree/command/ImportProjectsCommand.java
index 9aad28b2d9..69abf8da1d 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/repository/tree/command/ImportProjectsCommand.java
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/internal/repository/tree/command/ImportProjectsCommand.java
@@ -10,12 +10,17 @@
  *******************************************************************************/
 package org.eclipse.egit.ui.internal.repository.tree.command;
 
+import java.util.List;
+
 import org.eclipse.core.commands.ExecutionEvent;
 import org.eclipse.core.commands.ExecutionException;
+import org.eclipse.egit.ui.UIText;
 import org.eclipse.egit.ui.internal.clone.GitCreateProjectViaWizardWizard;
 import org.eclipse.egit.ui.internal.repository.tree.FolderNode;
 import org.eclipse.egit.ui.internal.repository.tree.RepositoryTreeNode;
+import org.eclipse.jface.dialogs.MessageDialog;
 import org.eclipse.jface.wizard.WizardDialog;
+import org.eclipse.swt.widgets.Display;
 
 /**
  * Implements "Add Projects" for Repository, Working Directory, and Folder
@@ -23,7 +28,21 @@ import org.eclipse.jface.wizard.WizardDialog;
 public class ImportProjectsCommand extends
 		RepositoriesViewCommandHandler<RepositoryTreeNode> {
 	public Object execute(ExecutionEvent event) throws ExecutionException {
-		RepositoryTreeNode node = getSelectedNodes(event).get(0);
+		List<RepositoryTreeNode> selectedNodes = getSelectedNodes(event);
+		if (selectedNodes == null || selectedNodes.isEmpty()) {
+			MessageDialog
+					.openError(Display.getDefault().getActiveShell(),
+					UIText.ImportProjectsWrongSelection,
+					UIText.ImportProjectsSelectionInRepositoryRequired);
+			return null;
+		}
+		if (!(((List) selectedNodes).get(0) instanceof RepositoryTreeNode)) {
+			MessageDialog.openError(Display.getDefault().getActiveShell(),
+					UIText.ImportProjectsWrongSelection,
+					UIText.ImportProjectsSelectionInRepositoryRequired);
+			return null;
+		}
+		RepositoryTreeNode node = selectedNodes.get(0);
 		String path;
 
 		switch (node.getType()) {
@@ -36,6 +55,9 @@ public class ImportProjectsCommand extends
 			path = ((FolderNode) node).getObject().getPath().toString();
 			break;
 		default:
+			MessageDialog.openError(Display.getDefault().getActiveShell(),
+					UIText.ImportProjectsWrongSelection,
+					UIText.ImportProjectsSelectionInRepositoryRequired);
 			return null;
 		}
 
diff --git a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
index 6e825f59d5..332b9132ab 100644
--- a/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
+++ b/org.eclipse.egit.ui/src/org/eclipse/egit/ui/uitext.properties
@@ -1407,6 +1407,10 @@ GitTraceConfigurationDialog_PlatformSwitchCheckbox=Enable &Platform Trace
 GitTraceConfigurationDialog_PlatformTraceDisabledMessage=Platform Trace is currently disabled, please enable it in order to edit the trace configuration
 GitTraceConfigurationDialog_ShellTitle=Git Trace Configuration
 GitTraceConfigurationDialog_TraceFileLocationLabel=Trace File &Location:
+
+ImportProjectsWrongSelection = Wrong selection
+ImportProjectsSelectionInRepositoryRequired = A folder selection in the Repository View is required
+
 LocalFileRevision_CurrentVersion=*({0})
 LocalFileRevision_currentVersionTag=<current version>
 LocalNonWorkspaceTypedElement_errorWritingContents=Error writing contents for local non-workspace element.