Set `MRB_STR_ASCII` flag to some stringize methods

- `Fixnum#to_s`, `Fixnum#inspect`
- `Float#to_s`, `Float#inspect`
- `NilClass#to_s`, `NilClass#inspect`
- `FalseClass#to_s`, `FalseClass#inspect`
- `TrueClass#to_s`, `TrueClass#inspect`
- `Time#to_s`, `Time#inspect`

3 files changed, 35 insertions, 13 deletions

diff --git a/mrbgems/mruby-time/src/time.c b/mrbgems/mruby-time/src/time.c
index caa8a01b5..c6680056a 100644
--- a/mrbgems/mruby-time/src/time.c
+++ b/mrbgems/mruby-time/src/time.c
@@ -12,6 +12,7 @@
 #include <mruby/class.h>
 #include <mruby/data.h>
 #include <mruby/time.h>
+#include <mruby/string.h>
 
 #ifndef MRB_DISABLE_STDIO
 #include <stdio.h>
@@ -952,7 +953,9 @@ mrb_time_to_s(mrb_state *mrb, mrb_value self)
   struct mrb_time *tm = time_get_ptr(mrb, self);
   mrb_bool utc = tm->timezone == MRB_TIMEZONE_UTC;
   size_t len = (utc ? time_to_s_utc : time_to_s_local)(mrb, tm, buf, sizeof(buf));
-  return mrb_str_new(mrb, buf, len);
+  mrb_value str = mrb_str_new(mrb, buf, len);
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 void
diff --git a/src/numeric.c b/src/numeric.c
index 60925841f..306b6ef4d 100644
--- a/src/numeric.c
+++ b/src/numeric.c
@@ -210,26 +210,30 @@ static mrb_value
 flo_to_s(mrb_state *mrb, mrb_value flt)
 {
   mrb_float f = mrb_float(flt);
+  mrb_value str;
 
   if (isinf(f)) {
-    return f < 0 ? mrb_str_new_lit(mrb, "-Infinity")
-                 : mrb_str_new_lit(mrb, "Infinity");
+    str = f < 0 ? mrb_str_new_lit(mrb, "-Infinity")
+                : mrb_str_new_lit(mrb, "Infinity");
+    goto exit;
   }
   else if (isnan(f)) {
-    return mrb_str_new_lit(mrb, "NaN");
+    str = mrb_str_new_lit(mrb, "NaN");
+    goto exit;
   }
   else {
     char fmt[] = "%." MRB_STRINGIZE(FLO_TO_STR_PREC) "g";
-    mrb_value str = mrb_float_to_str(mrb, flt, fmt);
     mrb_int len;
     char *begp, *p, *endp;
 
+    str = mrb_float_to_str(mrb, flt, fmt);
+
     insert_dot_zero:
     begp = RSTRING_PTR(str);
     len = RSTRING_LEN(str);
     for (p = begp, endp = p + len; p < endp; ++p) {
       if (*p == '.') {
-        return str;
+        goto exit;
       }
       else if (*p == 'e') {
         ptrdiff_t e_pos = p - begp;
@@ -237,7 +241,7 @@ flo_to_s(mrb_state *mrb, mrb_value flt)
         p = RSTRING_PTR(str) + e_pos;
         memmove(p + 2, p, len - e_pos);
         memcpy(p, ".0", 2);
-        return str;
+        goto exit;
       }
     }
 
@@ -247,8 +251,12 @@ flo_to_s(mrb_state *mrb, mrb_value flt)
       goto insert_dot_zero;
     }
 
-    return str;
+    goto exit;
   }
+
+  exit:
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 /* 15.2.9.3.2  */
@@ -1383,6 +1391,7 @@ mrb_fixnum_to_str(mrb_state *mrb, mrb_value x, mrb_int base)
   char buf[MRB_INT_BIT+1];
   char *b = buf + sizeof buf;
   mrb_int val = mrb_fixnum(x);
+  mrb_value str;
 
   if (base < 2 || 36 < base) {
     mrb_raisef(mrb, E_ARGUMENT_ERROR, "invalid radix %i", base);
@@ -1403,7 +1412,9 @@ mrb_fixnum_to_str(mrb_state *mrb, mrb_value x, mrb_int base)
     } while (val /= base);
   }
 
-  return mrb_str_new(mrb, b, buf + sizeof(buf) - b);
+  str = mrb_str_new(mrb, b, buf + sizeof(buf) - b);
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 /* 15.2.8.3.25 */
diff --git a/src/object.c b/src/object.c
index 33d570331..8de42a641 100644
--- a/src/object.c
+++ b/src/object.c
@@ -83,13 +83,17 @@ mrb_true(mrb_state *mrb, mrb_value obj)
 static mrb_value
 nil_to_s(mrb_state *mrb, mrb_value obj)
 {
-  return mrb_str_new_frozen(mrb, 0, 0);
+  mrb_value str = mrb_str_new_frozen(mrb, 0, 0);
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 static mrb_value
 nil_inspect(mrb_state *mrb, mrb_value obj)
 {
-  return mrb_str_new_lit_frozen(mrb, "nil");
+  mrb_value str = mrb_str_new_lit_frozen(mrb, "nil");
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 /***********************************************************************
@@ -150,7 +154,9 @@ true_xor(mrb_state *mrb, mrb_value obj)
 static mrb_value
 true_to_s(mrb_state *mrb, mrb_value obj)
 {
-  return mrb_str_new_lit_frozen(mrb, "true");
+  mrb_value str = mrb_str_new_lit_frozen(mrb, "true");
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 /* 15.2.5.3.4  */
@@ -257,7 +263,9 @@ false_or(mrb_state *mrb, mrb_value obj)
 static mrb_value
 false_to_s(mrb_state *mrb, mrb_value obj)
 {
-  return mrb_str_new_lit_frozen(mrb, "false");
+  mrb_value str = mrb_str_new_lit_frozen(mrb, "false");
+  RSTR_SET_ASCII_FLAG(mrb_str_ptr(str));
+  return str;
 }
 
 void