Clamp GetCommandsInRange against the remaining commands so a large count cannot overflow [patch]

UndoRedo.Test/UndoRedoStackTests.cs

@@ -240,6 +240,23 @@
 		Assert.IsTrue(saveBoundaryCreatedFired, "SaveBoundaryCreated event should fire when marking as saved");
 	}
 
+	[TestMethod]
+	public void GetCommandsInRange_CountOfIntMaxValueFromNonZeroStart_ReturnsRemainingCommands()
+	{
+		StackManager stack = new();
+		DelegateCommand first = new("A", () => { }, () => { });
+		DelegateCommand second = new("B", () => { }, () => { });
+		DelegateCommand third = new("C", () => { }, () => { });
+		stack.AddCommand(first);
+		stack.AddCommand(second);
+		stack.AddCommand(third);
+
+		// startIndex + count overflowed to a negative length before #105
+		CollectionAssert.AreEqual(new[] { second, third }, stack.GetCommandsInRange(1, int.MaxValue).ToList());
+		CollectionAssert.AreEqual(new[] { third }, stack.GetCommandsInRange(2, int.MaxValue).ToList());
+		CollectionAssert.AreEqual(new[] { second }, stack.GetCommandsInRange(1, 1).ToList());
+	}
+
 	private sealed class MockNavigationProvider : INavigationProvider
 	{
 		public string? LastNavigatedContext { get; private set; }

UndoRedo/Services/StackManager.cs

@@ -111,7 +111,8 @@ public IEnumerable<ICommand> GetCommandsInRange(int startIndex, int count)
 			return [];
 		}
 
-		int endIndex = Math.Min(startIndex + count, _commands.Count);
-		return _commands.GetRange(startIndex, endIndex - startIndex);
+		// Clamp against what remains rather than summing startIndex + count, which overflows for large counts
+		int available = _commands.Count - startIndex;
+		return _commands.GetRange(startIndex, Math.Min(count, available));
 	}
 }