From cb67b41a39afe3d001d7a36bf79e8333fcee50ae Mon Sep 17 00:00:00 2001
From: apio <blobs.trading@gmail.com>
Date: Fri, 7 Apr 2023 10:55:22 +0200
Subject: [PATCH] libc: Set errno in mbstowcs() and wcstombs()

---
 libc/src/stdlib.cpp | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/libc/src/stdlib.cpp b/libc/src/stdlib.cpp
index 6a880851..9a6ea3cd 100644
--- a/libc/src/stdlib.cpp
+++ b/libc/src/stdlib.cpp
@@ -107,23 +107,35 @@ extern "C"
     size_t mbstowcs(wchar_t* buf, const char* src, size_t max)
     {
         if (max == 0) return 0;
+        size_t result = (size_t)-1;
 
         Utf8StringDecoder decoder(src);
 
-        if (!buf) { return decoder.code_points().value_or((size_t)-1); }
+        if (!buf)
+        {
+            decoder.code_points().try_set_value_or_error(result, errno);
+            return result;
+        }
 
-        return decoder.decode(buf, max).value_or((size_t)-1);
+        decoder.decode(buf, max).try_set_value_or_error(result, errno);
+        return result;
     }
 
     size_t wcstombs(char* buf, const wchar_t* src, size_t max)
     {
         if (max == 0) return 0;
+        size_t result = (size_t)-1;
 
         Utf8StringEncoder encoder(src);
 
-        if (!buf) { return encoder.byte_length().value_or((size_t)-1); }
+        if (!buf)
+        {
+            encoder.byte_length().try_set_value_or_error(result, errno);
+            return result;
+        }
 
-        return encoder.encode(buf, max).value_or((size_t)-1);
+        encoder.encode(buf, max).try_set_value_or_error(result, errno);
+        return result;
     }
 
     void* malloc(size_t size)