From f841854c5f7e40a7248757098e6c7c530bbdddbe Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Wed, 21 Oct 2020 21:47:01 -0400
Subject: [PATCH] Fix crash logging into instances whose domain does not match
 the Instance uri field

---
 .../InstanceSelectorTableViewController.swift | 27 ++++++++++---------
 1 file changed, 15 insertions(+), 12 deletions(-)

diff --git a/Tusker/Screens/Onboarding/InstanceSelectorTableViewController.swift b/Tusker/Screens/Onboarding/InstanceSelectorTableViewController.swift
index 3dbb8993a6..726d04f250 100644
--- a/Tusker/Screens/Onboarding/InstanceSelectorTableViewController.swift
+++ b/Tusker/Screens/Onboarding/InstanceSelectorTableViewController.swift
@@ -57,7 +57,7 @@ class InstanceSelectorTableViewController: UITableViewController {
         
         dataSource = DataSource(tableView: tableView, cellProvider: { (tableView, indexPath, item) -> UITableViewCell? in
             switch item {
-            case let .selected(instance):
+            case let .selected(_, instance):
                 let cell = tableView.dequeueReusableCell(withIdentifier: instanceCell, for: indexPath) as! InstanceTableViewCell
                 cell.updateUI(instance: instance)
                 return cell
@@ -113,8 +113,9 @@ class InstanceSelectorTableViewController: UITableViewController {
     
     private func updateSpecificInstance(domain: String) {
         let components = parseURLComponents(input: domain)
+        let url = components.url!
 
-        let client = Client(baseURL: components.url!)
+        let client = Client(baseURL: url)
         let request = Client.getInstance()
         client.run(request) { (response) in
             var snapshot = self.dataSource.snapshot()
@@ -126,7 +127,7 @@ class InstanceSelectorTableViewController: UITableViewController {
                 if !snapshot.sectionIdentifiers.contains(.selected) {
                     snapshot.appendSections([.selected])
                 }
-                snapshot.appendItems([.selected(instance)], toSection: .selected)
+                snapshot.appendItems([.selected(url, instance)], toSection: .selected)
                 DispatchQueue.main.async {
                     self.dataSource.apply(snapshot)
                 }
@@ -168,10 +169,11 @@ class InstanceSelectorTableViewController: UITableViewController {
             return
         }
         switch item {
-        case let .selected(instance):
-            // we can't just turn the URI string from the API into a URL instance, because Mastodon only includes the domain in the "URI"
-            let components = parseURLComponents(input: instance.uri)
-            delegate.didSelectInstance(url: components.url!)
+        case let .selected(url, _):
+            // We can't rely on the URI reported by the instance API endpoint, because improperly configured instances may
+            // return a domain that they don't listen on. Instead, use the actual base URL that was used to make the /api/v1/instance
+            // request, since we know for certain that succeeded, otherwise this item wouldn't exist.
+            delegate.didSelectInstance(url: url)
         case let .recommended(instance):
             var components = URLComponents()
             components.scheme = "https"
@@ -188,13 +190,13 @@ extension InstanceSelectorTableViewController {
         case recommendedInstances
     }
     enum Item: Equatable, Hashable {
-        case selected(Instance)
+        case selected(URL, Instance)
         case recommended(InstanceSelector.Instance)
         
         static func ==(lhs: Item, rhs: Item) -> Bool {
-            if case let .selected(instance) = lhs,
-                case let .selected(other) = rhs {
-                return instance.uri == other.uri
+            if case let .selected(url, instance) = lhs,
+                case let .selected(otherUrl, other) = rhs {
+                return url == otherUrl && instance.uri == other.uri
             } else if case let .recommended(instance) = lhs,
                 case let .recommended(other) = rhs {
                 return instance.domain == other.domain
@@ -204,8 +206,9 @@ extension InstanceSelectorTableViewController {
         
         func hash(into hasher: inout Hasher) {
             switch self {
-            case let .selected(instance):
+            case let .selected(url, instance):
                 hasher.combine(Section.selected)
+                hasher.combine(url)
                 hasher.combine(instance.uri)
             case let .recommended(instance):
                 hasher.combine(Section.recommendedInstances)