1 files changed, 77 insertions, 0 deletions
diff --git a/src/SMAPI/Patches/CheckEventPreconditionErrorPatch.cs b/src/SMAPI/Patches/CheckEventPreconditionErrorPatch.cs
new file mode 100644
index 00000000..63eca5d7
--- /dev/null
+++ b/src/SMAPI/Patches/CheckEventPreconditionErrorPatch.cs
@@ -0,0 +1,77 @@
+using System.Diagnostics.CodeAnalysis;
+using System.Reflection;
+
+using Harmony;
+
+using StardewModdingAPI.Framework.Patching;
+using StardewModdingAPI.Framework.Reflection;
+
+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 CheckEventPreconditionErrorPatch : IHarmonyPatch {
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Writes messages to the console and log file on behalf of the game.</summary>
+        private static IMonitor MonitorForGame;
+
+        /// <summary>Local variable to store the patched method.</summary>
+        private static MethodInfo method;
+        /// <summary>Local variable to check if the method was already arbitrated.</summary>
+        private static bool isArbitrated;
+
+
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>A unique name for this patch.</summary>
+        public string Name => $"{nameof(CheckEventPreconditionErrorPatch)}";
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="monitorForGame">Writes messages to the console and log file on behalf of the game.</param>
+        /// <param name="reflector">Simplifies access to private code.</param>
+        public CheckEventPreconditionErrorPatch(IMonitor monitorForGame, Reflector reflector) {
+            CheckEventPreconditionErrorPatch.MonitorForGame = monitorForGame;
+        }
+
+
+        /// <summary>Apply the Harmony patch.</summary>
+        /// <param name="harmony">The Harmony instance.</param>
+        public void Apply(HarmonyInstance harmony) {
+            method = AccessTools.Method(typeof(GameLocation), "checkEventPrecondition");
+            MethodInfo transpiler = AccessTools.Method(this.GetType(), nameof(CheckEventPreconditionErrorPatch.Prefix));
+            harmony.Patch(method, new HarmonyMethod(transpiler));
+        }
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>The method to call instead of the GameLocation.CheckEventPrecondition.</summary>
+        /// <param name="__instance">The instance being patched.</param>
+        /// <param name="precondition">The precondition to be parsed.</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, string precondition) {
+            if (isArbitrated) {
+                isArbitrated = false;
+                return true;
+            } else {
+                isArbitrated = true;
+                try {
+                    method.Invoke(__instance, new object[] { precondition });
+                } catch (System.Exception ex) {
+                    CheckEventPreconditionErrorPatch.MonitorForGame.Log($"Failed parsing event info. Event precondition: {precondition}\n{ex}", LogLevel.Error);
+                }
+
+                return false;
+            }
+        }
+    }
+}