From ac01e7c47bc75d27e93106e9fb6ee13eabdc1606 Mon Sep 17 00:00:00 2001
From: wixoa <wixoag@gmail.com>
Date: Mon, 20 Jan 2025 23:57:37 -0500
Subject: [PATCH] Fix overriding runtime-initialized vars with constants
 (#2176)

---
 DMCompiler/DM/DMCodeTree.Vars.cs | 12 +++++++-----
 DMCompiler/DM/DMObject.cs        | 19 +++++++++++++------
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/DMCompiler/DM/DMCodeTree.Vars.cs b/DMCompiler/DM/DMCodeTree.Vars.cs
index 667b96cbfd..f7ff73d79c 100644
--- a/DMCompiler/DM/DMCodeTree.Vars.cs
+++ b/DMCompiler/DM/DMCodeTree.Vars.cs
@@ -43,13 +43,15 @@ protected void SetVariableValue(DMCompiler compiler, DMObject dmObject, DMVariab
 
             if (value.TryAsConstant(compiler, out var constant)) {
                 variable.Value = constant;
-                return;
+
+                // We want to continue with putting this in the init proc if a base type initializes it to another value
+                if (!isOverride || !dmObject.IsRuntimeInitialized(variable.Name)) {
+                    return;
+                }
             } else if (variable.IsConst) {
                 compiler.Emit(WarningCode.HardConstContext, value.Location, "Value of const var must be a constant");
                 return;
-            }
-
-            if (!IsValidRightHandSide(compiler, dmObject, value)) {
+            } else if (!IsValidRightHandSide(compiler, dmObject, value)) {
                 compiler.Emit(WarningCode.BadExpression, value.Location,
                     $"Invalid initial value for \"{variable.Name}\"");
                 return;
@@ -60,7 +62,7 @@ protected void SetVariableValue(DMCompiler compiler, DMObject dmObject, DMVariab
             var assign = new Assignment(initLoc, field, value);
 
             variable.Value = new Null(Location.Internal);
-            dmObject.InitializationProcExpressions.Add(assign);
+            dmObject.InitializationProcAssignments.Add((variable.Name, assign));
         }
 
         /// <returns>Whether the given value can be used as an instance variable's initial value</returns>
diff --git a/DMCompiler/DM/DMObject.cs b/DMCompiler/DM/DMObject.cs
index d48d84eb6f..10834f8433 100644
--- a/DMCompiler/DM/DMObject.cs
+++ b/DMCompiler/DM/DMObject.cs
@@ -1,4 +1,6 @@
-using DMCompiler.Bytecode;
+using System.Linq;
+using DMCompiler.Bytecode;
+using DMCompiler.DM.Expressions;
 using DMCompiler.Json;
 
 namespace DMCompiler.DM;
@@ -21,7 +23,7 @@ internal sealed class DMObject(DMCompiler compiler, int id, DreamPath path, DMOb
     public int? InitializationProc;
 
     /// <summary>A list of var and verb initializations implicitly done before the user's New() is called.</summary>
-    public readonly List<DMExpression> InitializationProcExpressions = new();
+    public readonly List<(string Name, Assignment Assignment)> InitializationProcAssignments = new();
 
     public bool IsRoot => Path == DreamPath.Root;
 
@@ -133,6 +135,11 @@ public void AddGlobalVariable(DMVariable global, int id) {
             TmpVariables.Add(global.Name);
     }
 
+    public bool IsRuntimeInitialized(string varName) {
+        return InitializationProcAssignments.Any(v => v.Name == varName)
+               || (Parent?.IsRuntimeInitialized(varName) ?? false);
+    }
+
     /// <summary>
     /// Recursively searches for a global/static with the given name.
     /// </summary>
@@ -152,16 +159,16 @@ public DMComplexValueType GetReturnType(string name) {
     }
 
     public void CreateInitializationProc() {
-        if (InitializationProcExpressions.Count <= 0 || InitializationProc != null)
+        if (InitializationProcAssignments.Count <= 0 || InitializationProc != null)
             return;
 
         var init = compiler.DMObjectTree.CreateDMProc(this, null);
         InitializationProc = init.Id;
         init.Call(DMReference.SuperProc, DMCallArgumentsType.None, 0);
 
-        foreach (DMExpression expression in InitializationProcExpressions) {
-            init.DebugSource(expression.Location);
-            expression.EmitPushValue(new(compiler, this, init));
+        foreach (var assignment in InitializationProcAssignments) {
+            init.DebugSource(assignment.Assignment.Location);
+            assignment.Assignment.EmitPushValue(new(compiler, this, init));
         }
     }