From a6b5bb439ca41a75bc5954c0b82b2a755ab2223c Mon Sep 17 00:00:00 2001
From: Andreas Kling <awesomekling@gmail.com>
Date: Thu, 25 Jul 2019 15:23:29 +0200
Subject: [PATCH] LibC: Don't clobber errno in free().

This one is a bit mysterious. I can't find any authoritative answer on what
the correct behavior is, but it seems reasonable to me that free() doesn't
step on errno, since it returns "void" and thus the caller won't know to
inspect errno anyway.
---
 Libraries/LibC/malloc.cpp | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/Libraries/LibC/malloc.cpp b/Libraries/LibC/malloc.cpp
index 7ad9f087ae..7495966366 100644
--- a/Libraries/LibC/malloc.cpp
+++ b/Libraries/LibC/malloc.cpp
@@ -1,5 +1,6 @@
 #include <AK/Bitmap.h>
 #include <AK/InlineLinkedList.h>
+#include <AK/ScopedValueRollback.h>
 #include <AK/Vector.h>
 #include <LibCore/CLock.h>
 #include <assert.h>
@@ -204,6 +205,8 @@ void* malloc(size_t size)
 
 void free(void* ptr)
 {
+    ScopedValueRollback rollback(errno);
+
     if (!ptr)
         return;