Piotr Caban : msvcrt: Fix error handling in _mbslwr_s_l.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: c54e0d93d9145055de2b2ea97bdb2c4af90055b8
URL:    https://gitlab.winehq.org/wine/wine/-/commit/c54e0d93d9145055de2b2ea97bdb2c4...

Author: Piotr Caban 
Date:   Wed Oct 19 13:44:53 2022 +0200

msvcrt: Fix error handling in _mbslwr_s_l.

---

dlls/msvcrt/mbcs.c         | 15 ++++++---------
 dlls/msvcrt/tests/string.c |  2 +-
 2 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/dlls/msvcrt/mbcs.c b/dlls/msvcrt/mbcs.c
index e275991343d..41a46f40495 100644
--- a/dlls/msvcrt/mbcs.c
+++ b/dlls/msvcrt/mbcs.c
@@ -2114,15 +2114,12 @@ unsigned char* CDECL _mbslwr(unsigned char* s)
  */
 int CDECL _mbslwr_s_l(unsigned char* s, size_t len, _locale_t locale)
 {
+  unsigned char *p = s;
+
   if (!s && !len)
-  {
     return 0;
-  }
-  else if (!s || !len)
-  {
-    *_errno() = EINVAL;
+  if (!MSVCRT_CHECK_PMT(s && len))
     return EINVAL;
-  }

if (get_mbcinfo()->ismbcodepage)
   {
@@ -2145,12 +2142,12 @@ int CDECL _mbslwr_s_l(unsigned char* s, size_t len, _locale_t locale)
       *s = _tolower_l(*s, locale);
   }

-  if (*s)
+  if (!MSVCRT_CHECK_PMT(len))
   {
-    *s = '\0';
-    *_errno() = EINVAL;
+    *p = 0;
     return EINVAL;
   }
+  *s = 0;
   return 0;
 }

diff --git a/dlls/msvcrt/tests/string.c b/dlls/msvcrt/tests/string.c
index 7a3d4b636b3..df3f5fceef8 100644
--- a/dlls/msvcrt/tests/string.c
+++ b/dlls/msvcrt/tests/string.c
@@ -2944,7 +2944,7 @@ static void test__mbslwr_s(void)

memcpy(buffer, "ABCDEFGH", sizeof("ABCDEFGH"));
     errno = EBADF;
-    ret = p_mbslwr_s(buffer, 4);
+    ret = p_mbslwr_s(buffer, sizeof("ABCDEFGH") - 1);
     ok(ret == EINVAL, "Expected _mbslwr_s to return EINVAL, got %d\n", ret);
     ok(errno == EINVAL, "Expected errno to be EINVAL, got %d\n", errno);