fix NullReferenceException if IEnumerable contains no elements

icsharpcode · Jan 28, 2012 · d4ce5d7 · d4ce5d7
1 parent d4e447a
commit d4ce5d7
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Showing 3 changed files with 5 additions and 3 deletions.
diff --git a/src/AddIns/Debugger/Debugger.AddIn/TreeModel/ArrayRangeNode.cs b/src/AddIns/Debugger/Debugger.AddIn/TreeModel/ArrayRangeNode.cs
@@ -14,7 +14,7 @@ public partial class Utils
 		public static IEnumerable<TreeNode> LazyGetChildNodesOfArray(TreeNode parent, Expression expression, ArrayDimensions dimensions)
 		{
 			if (dimensions.TotalElementCount == 0)
-				return new TreeNode[] { new TreeNode(null, "(empty)", null, null, parent, null) };
+				return new TreeNode[] { new TreeNode(null, "(empty)", null, null, parent, _ => null) };
 
 			return new ArrayRangeNode(parent, expression, dimensions, dimensions).ChildNodes;
 		}

diff --git a/src/AddIns/Debugger/Debugger.AddIn/TreeModel/ChildNodesOfObject.cs b/src/AddIns/Debugger/Debugger.AddIn/TreeModel/ChildNodesOfObject.cs
@@ -117,9 +117,9 @@ public static IEnumerable<TreeNode> LazyGetItemsOfIList(TreeNode parent, Express
 				error = e;
 			}
 			if (error != null) {
-				yield return new TreeNode(null, "(error)", error.Message, null, null, null);
+				yield return new TreeNode(null, "(error)", error.Message, null, null, _ => null);
 			} else if (count == 0) {
-				yield return new TreeNode(null, "(empty)", null, null, null, null);
+				yield return new TreeNode(null, "(empty)", null, null, null, _ => null);
 			} else {
 				for(int i = 0; i < count; i++) {
 					string imageName;

diff --git a/src/AddIns/Debugger/Debugger.AddIn/TreeModel/TreeNode.cs b/src/AddIns/Debugger/Debugger.AddIn/TreeModel/TreeNode.cs
@@ -118,6 +118,8 @@ public TreeNode(TreeNode parent)
 		public TreeNode(IImage iconImage, string name, string text, string type, TreeNode parent, Func<TreeNode, IEnumerable<TreeNode>> childNodes)
 			: this(parent)
 		{
+			if (childNodes == null)
+				throw new ArgumentNullException("childNodes");
 			this.iconImage = iconImage;
 			this.name = name;
 			this.text = text;