shlwapi: Output unrecognized format symbol in wvnsprintf().

CW-Bug-Id: #24355

Author: Paul Gofman

dlls/shlwapi/tests/string.c

@@ -1775,7 +1775,9 @@ static void test_printf_format(void)
         { "%I64llu", sizeof(ULONG64), "10", NULL, 10 },
         { "%I64s", sizeof(ULONG_PTR), "str", NULL, (ULONG_PTR)"str", L"str" },
         { "%q%u", sizeof(ULONG), "q10", NULL, 10 },
+        { "%lhw%u", 0, "%u", NULL, 10 },
         { "%u% ", sizeof(ULONG), "10", NULL, 10 },
+        { "%u% %u", sizeof(ULONG), "10%u", NULL, 10 },
         { "%  ll u", 0, " u", NULL, 10 },
         { "% llu", sizeof(ULONG64), "10", NULL, 10 },
         { "%# llx", sizeof(ULONG64), "0xa", NULL, 10 },

dlls/shlwapi/wsprintf.c

@@ -483,6 +483,7 @@ INT WINAPI wvnsprintfA( LPSTR buffer, INT maxlen, LPCSTR spec, va_list args )
             p += len - sign;
             break;
         case WPR_UNKNOWN:
+            if (*spec) *p++ = *spec++;
             continue;
         }
         if (format.flags & WPRINTF_LEFTALIGN)
@@ -603,6 +604,7 @@ INT WINAPI wvnsprintfW( LPWSTR buffer, INT maxlen, LPCWSTR spec, va_list args )
             for (i = sign; i < len; i++) *p++ = (BYTE)number[i];
             break;
         case WPR_UNKNOWN:
+            if (*spec) *p++ = *spec++;
             continue;
         }
         if (format.flags & WPRINTF_LEFTALIGN)