From c75a82336eeaa19c2632193c63d52c9435542182 Mon Sep 17 00:00:00 2001
From: Marti Maria <marti.maria@littlecms.com>
Date: Sun, 27 Oct 2024 18:48:12 +0100
Subject: [PATCH] Add the possibility of duplicating a NULL context for cloning
 defaults. Previously that was undefined behavior,

Fixes #462
---
 src/cmsplugin.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/cmsplugin.c b/src/cmsplugin.c
index 41b27999..36ac1b8c 100644
--- a/src/cmsplugin.c
+++ b/src/cmsplugin.c
@@ -906,7 +906,10 @@ cmsContext CMSEXPORT cmsDupContext(cmsContext ContextID, void* NewUserData)
     if (!InitContextMutex()) return NULL;
 
     // Setup default memory allocators
-    memcpy(&ctx->DefaultMemoryManager, &src->DefaultMemoryManager, sizeof(ctx->DefaultMemoryManager));
+    if (ContextID == NULL)
+        _cmsInstallAllocFunctions(NULL, &ctx->DefaultMemoryManager);
+    else
+        memcpy(&ctx->DefaultMemoryManager, &src->DefaultMemoryManager, sizeof(ctx->DefaultMemoryManager));
 
     // Maintain the linked list
     _cmsEnterCriticalSectionPrimitive(&_cmsContextPoolHeadMutex);