From 5dcee4fb9aed09357e07a09d9936e7e0161ca4ed Mon Sep 17 00:00:00 2001
From: Kurt <kaphotics@gmail.com>
Date: Thu, 24 Oct 2019 18:11:25 -0700
Subject: [PATCH] Set random moves if GetMoveSet yields invalid set

Closes #2406
No clean way to check for these edge scenarios, so just double check the
moveset and return random moves if we fail
---
 PKHeX.Core/Editing/CommonEdits.cs             | 24 +++++++++++++++----
 .../Controls/PKM Editor/PKMEditor.cs          |  2 +-
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/PKHeX.Core/Editing/CommonEdits.cs b/PKHeX.Core/Editing/CommonEdits.cs
index 0f7b04f4c..2abb8c35f 100644
--- a/PKHeX.Core/Editing/CommonEdits.cs
+++ b/PKHeX.Core/Editing/CommonEdits.cs
@@ -282,9 +282,15 @@ namespace PKHeX.Core
         /// Fetches <see cref="PKM.RelearnMoves"/> based on the provided <see cref="LegalityAnalysis"/>.
         /// </summary>
         /// <param name="pk">Pokémon to modify.</param>
+        /// <returns><see cref="PKM.RelearnMoves"/> best suited for the current <see cref="PKM"/> data.</returns>
+        public static IReadOnlyList<int> GetSuggestedRelearnMoves(this PKM pk) => new LegalityAnalysis(pk).GetSuggestedRelearnMoves();
+
+        /// <summary>
+        /// Fetches <see cref="PKM.RelearnMoves"/> based on the provided <see cref="LegalityAnalysis"/>.
+        /// </summary>
         /// <param name="legal"><see cref="LegalityAnalysis"/> which contains parsed information pertaining to legality.</param>
         /// <returns><see cref="PKM.RelearnMoves"/> best suited for the current <see cref="PKM"/> data.</returns>
-        public static IReadOnlyList<int> GetSuggestedRelearnMoves(this PKM pk, LegalityAnalysis legal)
+        public static IReadOnlyList<int> GetSuggestedRelearnMoves(this LegalityAnalysis legal)
         {
             var m = legal.GetSuggestedRelearn();
             if (m.Any(z => z != 0))
@@ -361,7 +367,7 @@ namespace PKHeX.Core
 
             var legal = new LegalityAnalysis(pk);
             if (legal.Parsed && legal.Info.Relearn.Any(z => !z.Valid))
-                pk.SetRelearnMoves(pk.GetSuggestedRelearnMoves(legal));
+                pk.SetRelearnMoves(legal.GetSuggestedRelearnMoves());
             pk.RefreshChecksum();
         }
 
@@ -606,7 +612,17 @@ namespace PKHeX.Core
         public static int[] GetMoveSet(this PKM pkm, bool random = false)
         {
             var la = new LegalityAnalysis(pkm);
-            return pkm.GetMoveSet(la, random);
+            var moves = pkm.GetMoveSet(la, random);
+
+            if (random)
+                return moves;
+
+            var clone = pkm.Clone();
+            clone.SetMoves(moves);
+            var newLa = new LegalityAnalysis(pkm);
+
+            // ReSharper disable once TailRecursiveCall
+            return newLa.Valid ? moves : GetMoveSet(pkm, true);
         }
 
         /// <summary>
@@ -630,7 +646,7 @@ namespace PKHeX.Core
 
             const int count = 4;
             if (m.Length > count)
-                return m.Skip(m.Length - count).ToArray();
+                return m.SliceEnd(m.Length - count);
             Array.Resize(ref m, count);
             return m;
         }
diff --git a/PKHeX.WinForms/Controls/PKM Editor/PKMEditor.cs b/PKHeX.WinForms/Controls/PKM Editor/PKMEditor.cs
index 9c22c1dd8..98be563c4 100644
--- a/PKHeX.WinForms/Controls/PKM Editor/PKMEditor.cs	
+++ b/PKHeX.WinForms/Controls/PKM Editor/PKMEditor.cs	
@@ -671,7 +671,7 @@ namespace PKHeX.WinForms.Controls
             if (pkm.Format < 6)
                 return false;
 
-            var m = pkm.GetSuggestedRelearnMoves(Legality);
+            var m = Legality.GetSuggestedRelearnMoves();
             if (pkm.RelearnMoves.SequenceEqual(m))
                 return false;