Change the `mrb_vformat` specifier `%d` for `int`

It potentially breaks, for example, in the case of `mrb_int` is 64-bit
and more smaller type is passed by `%d`. In fact, the problem could
become apparent when I used `%d` to `backtrace_location::lineno` in
`src/backtrace.c:mrb_unpack_backtrace()` on AppVeyor.

Therefore, change `%d` for `int` (not `mrb_int`) so that it can be
used mostly without casting.

1 files changed, 5 insertions, 3 deletions

diff --git a/src/error.c b/src/error.c
index d8224622b..6e7c3763a 100644
--- a/src/error.c
+++ b/src/error.c
@@ -282,8 +282,9 @@ mrb_raise(mrb_state *mrb, struct RClass *c, const char *msg)
  *   Specifier | Argument Type  | Note
  *   ----------+----------------+--------------------------------------------
  *       c     | char           |
- *      d,i    | mrb_int        |
+ *       d     | int            |
  *       f     | mrb_float      |
+ *       i     | mrb_int        |
  *       l     | char*, mrb_int | Arguments are string and length.
  *       n     | mrb_sym        |
  *       s     | char*          | Argument is NUL terminated string.
@@ -303,7 +304,7 @@ mrb_vformat(mrb_state *mrb, const char *format, va_list ap)
   const char *chars, *p = format, *b = format, *e;
   char ch;
   struct RClass *cls;
-  mrb_int len;
+  mrb_int len, i;
   mrb_bool inspect = FALSE;
   mrb_value result = mrb_str_new_capa(mrb, 128), obj, str;
   int ai = mrb_gc_arena_save(mrb);
@@ -324,7 +325,8 @@ mrb_vformat(mrb_state *mrb, const char *format, va_list ap)
           len = 1;
           goto L_cat;
         case 'd': case 'i':
-          obj = mrb_fixnum_value(va_arg(ap, mrb_int));
+          i = *p == 'd' ? (mrb_int)va_arg(ap, int) : va_arg(ap, mrb_int);
+          obj = mrb_fixnum_value(i);
           goto L_cat_obj;
         case 'f':
           obj = mrb_float_value(mrb, va_arg(ap, mrb_float));