From 33ab8be7e3a32182e1397e403d6ee8a5e8b342c8 Mon Sep 17 00:00:00 2001
From: Joram Vandemoortele <joram.vdm@gmail.com>
Date: Sun, 4 Apr 2021 20:24:48 +0200
Subject: [PATCH] fix possibility of having no reallocate function (#954)

Before, if a config was provided it was expected to have a reallocate function, now it can remain null and the default will be used.
---
 src/vm/wren_vm.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/vm/wren_vm.c b/src/vm/wren_vm.c
index a63f973e..dd8a8b63 100644
--- a/src/vm/wren_vm.c
+++ b/src/vm/wren_vm.c
@@ -56,8 +56,8 @@ WrenVM* wrenNewVM(WrenConfiguration* config)
   WrenReallocateFn reallocate = defaultReallocate;
   void* userData = NULL;
   if (config != NULL) {
-    reallocate = config->reallocateFn;
     userData = config->userData;
+    reallocate = config->reallocateFn ? config->reallocateFn : defaultReallocate;
   }
   
   WrenVM* vm = (WrenVM*)reallocate(NULL, sizeof(*vm), userData);
@@ -67,6 +67,10 @@ WrenVM* wrenNewVM(WrenConfiguration* config)
   if (config != NULL)
   {
     memcpy(&vm->config, config, sizeof(WrenConfiguration));
+
+    // We choose to set this after copying, 
+    // rather than modifying the user config pointer
+    vm->config.reallocateFn = reallocate;
   }
   else
   {