From 2e71cc573d1d890a7cd75ee9ef29429a75cc4409 Mon Sep 17 00:00:00 2001
From: Maurice Parker <mo@vincode.io>
Date: Tue, 3 Sep 2019 12:07:18 -0500
Subject: [PATCH] Cap the possible destination index used during Feed moves

---
 iOS/MasterFeed/MasterFeedViewController.swift | 2 +-
 iOS/SceneCoordinator.swift                    | 7 +++++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/iOS/MasterFeed/MasterFeedViewController.swift b/iOS/MasterFeed/MasterFeedViewController.swift
index a7eaa4146..6dc3d6e88 100644
--- a/iOS/MasterFeed/MasterFeedViewController.swift
+++ b/iOS/MasterFeed/MasterFeedViewController.swift
@@ -269,7 +269,7 @@ class MasterFeedViewController: UITableViewController, UndoableCommandRunner {
 			if proposedDestinationIndexPath.section == 0 {
 				return IndexPath(row: 0, section: 1)
 			}
-			return proposedDestinationIndexPath
+			return coordinator.cappedIndexPath(proposedDestinationIndexPath)
 		}()
 		
 		guard let draggedNode = coordinator.nodeFor(sourceIndexPath), let destNode = coordinator.nodeFor(destIndexPath), let parentNode = destNode.parent else {
diff --git a/iOS/SceneCoordinator.swift b/iOS/SceneCoordinator.swift
index 544a848f6..f5f1924af 100644
--- a/iOS/SceneCoordinator.swift
+++ b/iOS/SceneCoordinator.swift
@@ -357,6 +357,13 @@ class SceneCoordinator: NSObject, UndoableCommandRunner, UnreadCountProvider {
 		return shadowTable[section]
 	}
 	
+	func cappedIndexPath(_ indexPath: IndexPath) -> IndexPath {
+		guard indexPath.section < shadowTable.count && indexPath.row < shadowTable[indexPath.section].count else {
+			return IndexPath(row: shadowTable[shadowTable.count - 1].count - 1, section: shadowTable.count - 1)
+		}
+		return indexPath
+	}
+	
 	func indexPathFor(_ node: Node) -> IndexPath? {
 		for i in 0..<shadowTable.count {
 			if let row = shadowTable[i].firstIndex(of: node) {