msvcrt: Implement %u format for strftime.

dlls/msvcrt/tests/time.c

@@ -654,6 +654,11 @@ static void test_strftime(void)
     ok(errno==EINVAL || broken(errno==0xdeadbeef), "errno = %d\n", errno);
 
     errno = 0xdeadbeef;
+    retA = p_strftime(bufA, 256, "%u", gmt_tm);
+    ok(retA == 0, "expected 0, got %ld\n", retA);
+    ok(errno==EINVAL || broken(errno==0xdeadbeef), "errno = %d\n", errno);
+
+    errno = 0xdeadbeef;
     retA = p_strftime(NULL, 0, "copy", gmt_tm);
     ok(retA == 0, "expected 0, got %ld\n", retA);
     ok(errno==EINVAL || broken(errno==0xdeadbeef), "errno = %d\n", errno);

dlls/msvcrt/time.c

@@ -1264,6 +1264,11 @@ static MSVCRT_size_t strftime_helper(char *str, MSVCRT_size_t max, const char *f
             if(!strftime_int(str, &ret, max, mstm->tm_sec, alternate ? 0 : 2, 0, 59))
                 return 0;
             break;
+        case 'u':
+            tmp = mstm->tm_wday ? mstm->tm_wday : 7;
+            if(!strftime_int(str, &ret, max, tmp, 0, 1, 7))
+                return 0;
+            break;
 #endif
         case 'w':
             if(!strftime_int(str, &ret, max, mstm->tm_wday, 0, 0, 6))

dlls/ucrtbase/tests/misc.c

@@ -901,6 +901,7 @@ static void test_asctime(void)
 static void test_strftime(void)
 {
     const struct tm epoch = { 0, 0, 0, 1, 0, 70, 4, 0, 0 };
+    const struct tm tm1 = { 0, 0, 0, 1, 0, 117, 0, 0, 0 };
     char bufA[256];
     size_t retA;
 
@@ -948,6 +949,10 @@ static void test_strftime(void)
     ok(retA == 5, "expected 5, got %d\n", (int)retA);
     ok(!strcmp(bufA, "0:0:0"), "got %s\n", bufA);
 
+    retA = p_strftime(bufA, sizeof(bufA), "%u", &tm1);
+    ok(retA == 1, "expected 1, got %d\n", (int)retA);
+    ok(!strcmp(bufA, "7"), "got %s\n", bufA);
+
     retA = p_strftime(bufA, sizeof(bufA), "%h", &epoch);
     ok(retA == 3, "expected 3, got %d\n", (int)retA);
     ok(!strcmp(bufA, "Jan"), "got %s\n", bufA);