Report download errors for correct modules, don't re-download

Author: HebaruSan

Core/Extensions/EnumerableExtensions.cs

@@ -60,6 +60,10 @@ public static void RemoveWhere<K, V>(this Dictionary<K, V> source,
             }
         }
 
+        public static bool IntersectsWith<T>(this IEnumerable<T> source,
+                                             IEnumerable<T>      other)
+            => source.Intersect(other).Any();
+
         /// <summary>
         /// Sum a sequence of TimeSpans.
         /// Mysteriously not defined standardly.

GUI/Main/MainDownload.cs

@@ -6,6 +6,7 @@
 using System.Threading.Tasks;
 
 using CKAN.GUI.Attributes;
+using CKAN.Extensions;
 
 namespace CKAN.GUI
 {
@@ -59,7 +60,8 @@ private void CacheMods(object? sender, DoWorkEventArgs? e)
                 {
                     try
                     {
-                        downloader.DownloadModules(modules.Select(m => m.Module));
+                        downloader.DownloadModules(modules.Where(m => !m.IsCached)
+                                                          .Select(m => m.Module));
                         done = true;
                     }
                     catch (ModuleDownloadErrorsKraken k)
@@ -72,7 +74,11 @@ private void CacheMods(object? sender, DoWorkEventArgs? e)
                                 Properties.Resources.ModDownloadsFailedColHdr,
                                 Properties.Resources.ModDownloadsFailedAbortBtnNotInstalling,
                                 k.Exceptions.Select(kvp => new KeyValuePair<object[], Exception>(
-                                    modules.Select(m => m.Module).ToArray(), kvp.Value)),
+                                    modules.Select(m => m.Module)
+                                           .Where(m => (m.download ?? Enumerable.Empty<Uri>())
+                                                           .IntersectsWith(kvp.Key?.download ?? Enumerable.Empty<Uri>()))
+                                           .ToArray(),
+                                    kvp.Value)),
                                 (m1, m2) => (m1 as CkanModule)?.download == (m2 as CkanModule)?.download);
                              dfd.ShowDialog(this);
                         });

GUI/Main/MainInstall.cs

@@ -14,6 +14,7 @@
 using CKAN.IO;
 using CKAN.GUI.Attributes;
 using CKAN.Configuration;
+using CKAN.Extensions;
 
 // Don't warn if we use our own obsolete properties
 #pragma warning disable 0618
@@ -286,7 +287,9 @@ private void InstallMods(object? sender, DoWorkEventArgs? e)
                                     Properties.Resources.ModDownloadsFailedColHdr,
                                     Properties.Resources.ModDownloadsFailedAbortBtn,
                                     k.Exceptions.Select(kvp => new KeyValuePair<object[], Exception>(
-                                        fullChangeset.Where(m => m.download == kvp.Key.download).ToArray(),
+                                        fullChangeset.Where(m => (m.download ?? Enumerable.Empty<Uri>())
+                                                                     .IntersectsWith(kvp.Key.download ?? Enumerable.Empty<Uri>()))
+                                                     .ToArray(),
                                         kvp.Value)),
                                     (m1, m2) => (m1 as CkanModule)?.download == (m2 as CkanModule)?.download);
                                  dfd.ShowDialog(this);

Tests/Core/Extensions/EnumerableExtensionsTests.cs

@@ -10,6 +10,15 @@ namespace Tests.Core.Extensions
     [TestFixture]
     public class EnumerableExtensionsTests
     {
+        [TestCase(new string[] { "A", "B", "C", "D" },
+                  new string[] { "A", "S", "D", "F" },
+                  ExpectedResult = true),
+         TestCase(new string[] { "A", "B", "C", "D" },
+                  new string[] { "E", "F", "G", "H" },
+                  ExpectedResult = false)]
+        public bool IntersectsWith_Examples_Works(string[] a, string[] b)
+            => a.IntersectsWith(b);
+
         [TestCaseSource(nameof(TimeSpanCases))]
         public TimeSpan Sum_Timespans_Works(TimeSpan[] spans)
             => spans.Sum();