From 485c0ef691822873df8a6961ec099779ff19412c Mon Sep 17 00:00:00 2001
From: Tim Schumacher <timschumi@gmx.de>
Date: Wed, 22 Sep 2021 10:21:06 +0000
Subject: [PATCH] LibC: Implement wmemcpy

---
 Tests/LibC/TestWchar.cpp          | 17 +++++++++++++++++
 Userland/Libraries/LibC/wchar.cpp |  8 ++++++++
 Userland/Libraries/LibC/wchar.h   |  1 +
 3 files changed, 26 insertions(+)

diff --git a/Tests/LibC/TestWchar.cpp b/Tests/LibC/TestWchar.cpp
index 82e658366a..776f776386 100644
--- a/Tests/LibC/TestWchar.cpp
+++ b/Tests/LibC/TestWchar.cpp
@@ -6,6 +6,7 @@
 
 #include <LibTest/TestCase.h>
 
+#include <string.h>
 #include <wchar.h>
 
 TEST_CASE(wcspbrk)
@@ -97,6 +98,22 @@ TEST_CASE(wmemchr)
     EXPECT_EQ(ret, input + 6);
 }
 
+TEST_CASE(wmemcpy)
+{
+    const wchar_t* input = L"abc\0def";
+    auto buf = static_cast<wchar_t*>(malloc(8 * sizeof(wchar_t)));
+
+    if (!buf) {
+        FAIL("Could not allocate space for copy target");
+        return;
+    }
+
+    wchar_t* ret = wmemcpy(buf, input, 8);
+
+    EXPECT_EQ(ret, buf);
+    EXPECT_EQ(memcmp(buf, input, 8 * sizeof(wchar_t)), 0);
+}
+
 TEST_CASE(wcscoll)
 {
     // Check if wcscoll is sorting correctly. At the moment we are doing raw char comparisons,
diff --git a/Userland/Libraries/LibC/wchar.cpp b/Userland/Libraries/LibC/wchar.cpp
index a3927111d3..052ab8b1cc 100644
--- a/Userland/Libraries/LibC/wchar.cpp
+++ b/Userland/Libraries/LibC/wchar.cpp
@@ -385,4 +385,12 @@ wchar_t* wmemchr(const wchar_t* s, wchar_t c, size_t n)
 
     return nullptr;
 }
+
+wchar_t* wmemcpy(wchar_t* dest, const wchar_t* src, size_t n)
+{
+    for (size_t i = 0; i < n; i++)
+        dest[i] = src[i];
+
+    return dest;
+}
 }
diff --git a/Userland/Libraries/LibC/wchar.h b/Userland/Libraries/LibC/wchar.h
index 5ec7f9e253..a622906218 100644
--- a/Userland/Libraries/LibC/wchar.h
+++ b/Userland/Libraries/LibC/wchar.h
@@ -44,5 +44,6 @@ int mbsinit(const mbstate_t*);
 wchar_t* wcspbrk(const wchar_t*, const wchar_t*);
 wchar_t* wcsstr(const wchar_t*, const wchar_t*);
 wchar_t* wmemchr(const wchar_t*, wchar_t, size_t);
+wchar_t* wmemcpy(wchar_t*, const wchar_t*, size_t);
 
 __END_DECLS