From 560ac90ba059f663f5d9221c619355051d20678f Mon Sep 17 00:00:00 2001
From: Piotr Caban <piotr@codeweavers.com>
Date: Mon, 4 Jan 2021 13:51:22 +0100
Subject: [PATCH] msvcr100: Use LC_TIME code page when converting strftime
 data.

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=50151
Signed-off-by: Piotr Caban <piotr@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>
---
 dlls/msvcrt/time.c         | 24 +++++++++++++++++++-----
 dlls/ucrtbase/tests/misc.c |  9 +++++++++
 2 files changed, 28 insertions(+), 5 deletions(-)

diff --git a/dlls/msvcrt/time.c b/dlls/msvcrt/time.c
index 60b8c8575d3..327d8e086e0 100644
--- a/dlls/msvcrt/time.c
+++ b/dlls/msvcrt/time.c
@@ -22,6 +22,7 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
  */
 
+#include <locale.h>
 #include <stdlib.h>
 #include <time.h>
 #include <sys/timeb.h>
@@ -1437,6 +1438,7 @@ static size_t strftime_helper(char *str, size_t max, const char *format,
 #else
     wchar_t *s, *fmt;
     size_t len;
+    int cp;
 
     TRACE("(%p %Iu %s %p %p %p)\n", str, max, format, mstm, time_data, loc);
 
@@ -1445,15 +1447,27 @@ static size_t strftime_helper(char *str, size_t max, const char *format,
     *str = 0;
     if (!MSVCRT_CHECK_PMT(format != NULL)) return 0;
 
-    len = _mbstowcs_l( NULL, format, 0, loc ) + 1;
-    if (!len || !(fmt = malloc( len*sizeof(wchar_t) ))) return 0;
-    _mbstowcs_l(fmt, format, len, loc);
+    cp = (loc ? loc->locinfo : get_locinfo())->lc_id[LC_TIME].wCodePage;
+
+    len = MultiByteToWideChar( cp, 0, format, -1, NULL, 0 );
+    if (!len)
+    {
+        *_errno() = EILSEQ;
+        return 0;
+    }
+    fmt = malloc( len*sizeof(wchar_t) );
+    if (!fmt) return 0;
+    MultiByteToWideChar( cp, 0, format, -1, fmt, len );
 
     if ((s = malloc( max*sizeof(wchar_t) )))
     {
         len = strftime_impl( s, max, fmt, mstm, time_data, loc );
         if (len)
-            len = _wcstombs_l( str, s, max, loc );
+        {
+            len = WideCharToMultiByte( cp, 0, s, -1, str, max, NULL, NULL );
+            if (len) len--;
+            else *_errno() = EILSEQ;
+        }
         free( s );
     }
     else len = 0;
@@ -1478,7 +1492,7 @@ size_t CDECL _strftime_l( char *str, size_t max, const char *format,
  *		_Strftime (MSVCRT.@)
  */
 size_t CDECL _Strftime(char *str, size_t max, const char *format,
-        const struct tm *mstm, __lc_time_data *time_data)
+        const struct tm *mstm, void *time_data)
 {
     return strftime_helper(str, max, format, mstm, time_data, NULL);
 }
diff --git a/dlls/ucrtbase/tests/misc.c b/dlls/ucrtbase/tests/misc.c
index f15585369cb..5fcec2e2bb5 100644
--- a/dlls/ucrtbase/tests/misc.c
+++ b/dlls/ucrtbase/tests/misc.c
@@ -1112,6 +1112,15 @@ static void test_strftime(void)
     ok(ret == 8, "ret = %d\n", ret);
     ok(!strcmp(buf, "00:00:00"), "buf = \"%s\", expected \"%s\"\n", buf, "00:00:00");
     setlocale(LC_ALL, "C");
+
+    if(!setlocale(LC_TIME, "Japanese_Japan.932")) {
+        win_skip("Japanese_Japan.932 locale not available\n");
+        return;
+    }
+    ret = strftime(buf, sizeof(buf), "%a", &epoch);
+    ok(ret == 2 || broken(ret == 1), "ret = %d\n", ret);
+    ok(!strcmp(buf, "\x96\xd8"), "buf = %s, expected \"\\x96\\xd8\"\n", wine_dbgstr_an(buf, 2));
+    setlocale(LC_ALL, "C");
 }
 
 static LONG* get_failures_counter(HANDLE *map)