From b26c8e3b9e85c09c908332c52704aa552a2170e3 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 16 Aug 2018 14:02:49 +0900
Subject: [PATCH 1/2] Fix notifiation stack trace output on mania conversion
 failure

---
 .../Beatmaps/Patterns/PatternGenerator.cs     | 34 ++++++++++++++-----
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs b/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs
index 3434c9f01e..1f416f921e 100644
--- a/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs
+++ b/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs
@@ -55,15 +55,18 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns
         {
             int iterations = 0;
 
-            while (condition() && iterations++ < max_rng_iterations)
+            while (condition())
+            {
+                if (iterations++ >= max_rng_iterations)
+                {
+                    // log an error but don't throw. we want to continue execution.
+                    Logger.Error(new ExceededAllowedIterationsException(new StackTrace(0)),
+                        "Conversion encountered errors. The beatmap may not be correctly converted.");
+                    return;
+                }
+
                 action();
-
-            if (iterations < max_rng_iterations)
-                return;
-
-            // Generate + log an error/stacktrace
-
-            Logger.Log($"Allowable iterations ({max_rng_iterations}) exceeded:\n{new StackTrace(0)}", level: LogLevel.Error);
+            }
         }
 
         /// <summary>
@@ -71,5 +74,20 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns
         /// </summary>
         /// <returns>The <see cref="Pattern"/>s containing the hit objects.</returns>
         public abstract IEnumerable<Pattern> Generate();
+
+        /// <summary>
+        /// Denotes when a single conversion operation is in an infinitely looping state.
+        /// </summary>
+        public class ExceededAllowedIterationsException : Exception
+        {
+            private readonly string stackTrace;
+
+            public ExceededAllowedIterationsException(StackTrace stackTrace)
+            {
+                this.stackTrace = stackTrace.ToString();
+            }
+
+            public override string StackTrace => stackTrace;
+        }
     }
 }

From dfecb3235b7d3d0bbf0d694f1528071aa87e61b0 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Thu, 16 Aug 2018 20:41:53 +0900
Subject: [PATCH 2/2] Fix custom exception stack trace output

---
 osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs | 1 +
 1 file changed, 1 insertion(+)

diff --git a/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs b/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs
index 1f416f921e..1eb0cdae2f 100644
--- a/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs
+++ b/osu.Game.Rulesets.Mania/Beatmaps/Patterns/PatternGenerator.cs
@@ -88,6 +88,7 @@ namespace osu.Game.Rulesets.Mania.Beatmaps.Patterns
             }
 
             public override string StackTrace => stackTrace;
+            public override string ToString() => $"{GetType().Name}: {Message}\r\n{StackTrace}";
         }
     }
 }