1 files changed, 84 insertions, 0 deletions
diff --git a/src/SMAPI/Patches/EventErrorPatch.cs b/src/SMAPI/Patches/EventErrorPatch.cs
new file mode 100644
index 00000000..b0074356
--- /dev/null
+++ b/src/SMAPI/Patches/EventErrorPatch.cs
@@ -0,0 +1,84 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+using Harmony;
+using StardewModdingAPI.Framework.Patching;
+using StardewValley;
+
+namespace StardewModdingAPI.Patches
+{
+    /// <summary>A Harmony patch for the <see cref="Dialogue"/> constructor which intercepts invalid dialogue lines and logs an error instead of crashing.</summary>
+    internal class EventErrorPatch : IHarmonyPatch
+    {
+        /*********
+        ** Fields
+        *********/
+        /// <summary>Writes messages to the console and log file on behalf of the game.</summary>
+        private static IMonitor MonitorForGame;
+
+        /// <summary>Whether the method is currently being intercepted.</summary>
+        private static bool IsIntercepted;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A unique name for this patch.</summary>
+        public string Name => $"{nameof(EventErrorPatch)}";
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="monitorForGame">Writes messages to the console and log file on behalf of the game.</param>
+        public EventErrorPatch(IMonitor monitorForGame)
+        {
+            EventErrorPatch.MonitorForGame = monitorForGame;
+        }
+
+        /// <summary>Apply the Harmony patch.</summary>
+        /// <param name="harmony">The Harmony instance.</param>
+        public void Apply(HarmonyInstance harmony)
+        {
+            harmony.Patch(
+                original: AccessTools.Method(typeof(GameLocation), "checkEventPrecondition"),
+                prefix: new HarmonyMethod(this.GetType(), nameof(EventErrorPatch.Prefix))
+            );
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>The method to call instead of the GameLocation.CheckEventPrecondition.</summary>
+        /// <param name="__instance">The instance being patched.</param>
+        /// <param name="__result">The return value of the original method.</param>
+        /// <param name="precondition">The precondition to be parsed.</param>
+        /// <param name="__originalMethod">The method being wrapped.</param>
+        /// <returns>Returns whether to execute the original method.</returns>
+        /// <remarks>This method must be static for Harmony to work correctly. See the Harmony documentation before renaming arguments.</remarks>
+        [SuppressMessage("ReSharper", "InconsistentNaming", Justification = "Argument names are defined by Harmony.")]
+        private static bool Prefix(GameLocation __instance, ref int __result, string precondition, MethodInfo __originalMethod)
+        {
+            if (EventErrorPatch.IsIntercepted)
+                return true;
+
+            try
+            {
+                EventErrorPatch.IsIntercepted = true;
+                __result = (int)__originalMethod.Invoke(__instance, new object[] { precondition });
+                return false;
+            }
+            catch (TargetInvocationException ex)
+            {
+                __result = -1;
+                EventErrorPatch.MonitorForGame.Log($"Failed parsing event precondition ({precondition}):\n{ex.InnerException}", LogLevel.Error);
+                return false;
+            }
+            finally
+            {
+                EventErrorPatch.IsIntercepted = false;
+            }
+        }
+    }
+}