Update JSEnvironmentVariableMap.cpp

src/bun.js/bindings/JSEnvironmentVariableMap.cpp

@@ -287,12 +287,18 @@ JSValue createEnvironmentVariablesMap(Zig::GlobalObject* globalObject)
     void* list;
     size_t count = Bun__getEnvCount(globalObject, &list);
     JSC::JSObject* object = nullptr;
-    if (count < 63) {
-        object = constructEmptyObject(globalObject, globalObject->objectPrototype(), count);
-    } else {
-        object = constructEmptyObject(globalObject, globalObject->objectPrototype());
-    }
 
+#if OS(WINDOWS)
+    object = JSC::constructEmptyObject(vm, globalObject->nullPrototypeObjectStructure());
+#else
+    JSObject* prototype = globalObject->objectPrototype();
+
+    if (count < JSFinalObject::maxInlineCapacity) {
+        object = constructEmptyObject(globalObject, prototype, count);
+    } else {
+        object = constructEmptyObject(globalObject, prototype);
+    }
+#endif
 #if OS(WINDOWS)
     JSArray* keyArray = constructEmptyArray(globalObject, nullptr, count);
     RETURN_IF_EXCEPTION(scope, {});

src/js/builtins/ProcessObjectInternals.ts

@@ -414,7 +414,7 @@ export function windowsEnv(
       }
       if (internalEnv[k] !== value) {
         editWindowsEnvVar(k, value);
-        internalEnv[k] = value;
+        $putByValDirect(internalEnv, k, value);
       }
       return true;
     },

test/regression/issue/20514.test.ts

@@ -0,0 +1,14 @@
+import { expect, test } from "bun:test";
+
+// https://github.com/oven-sh/bun/issues/20514
+test("test", () => {
+  expect([
+    "-p",
+    `Object.defineProperty(Object.prototype, "1", {
+      set: function (value) {
+        throw new Error();
+      }
+});
+const homeDir = process.env.HOME || process.env.USERPROFILE;`,
+  ]).toRun();
+});