numeric.c (int_div): add checks for division by zero.

mrbgems/mruby-bigint/core/bigint.c

@@ -1180,6 +1180,9 @@ mrb_bint_div(mrb_state *mrb, mrb_value x, mrb_value y)
     return mrb_float_value(mrb,v1*v2);
   }
 #endif
+  if (mrb_integer_p(y) && mrb_integer(y) == 0) {
+    mrb_int_zerodiv(mrb);
+  }
   y = mrb_as_bint(mrb, y);
   struct RBigint *b = RBIGINT(x);
   struct RBigint *b2 = RBIGINT(y);

mrbgems/mruby-complex/src/complex.c

@@ -1,6 +1,7 @@
 #include <mruby.h>
 #include <mruby/class.h>
 #include <mruby/numeric.h>
+#include <mruby/internal.h>
 #include <mruby/presym.h>
 
 #ifdef MRB_NO_FLOAT
@@ -308,6 +309,9 @@ mrb_complex_div(mrb_state *mrb, mrb_value self, mrb_value rhs)
 
   a = complex_ptr(mrb, self);
   if (mrb_type(rhs) != MRB_TT_COMPLEX) {
+    if (mrb_integer_p(rhs) && mrb_integer(rhs) == 0) {
+      mrb_int_zerodiv(mrb);
+    }
     mrb_float f = mrb_as_float(mrb, rhs);
     return complex_new(mrb, mrb_div_float(a->real, f), mrb_div_float(a->imaginary, f));
   }

mrbgems/mruby-rational/src/rational.c

@@ -1,6 +1,7 @@
 #include <mruby.h>
 #include <mruby/class.h>
 #include <mruby/numeric.h>
+#include <mruby/internal.h>
 #include <mruby/presym.h>
 
 #ifndef MRB_NO_FLOAT
@@ -647,6 +648,7 @@ mrb_rational_div(mrb_state *mrb, mrb_value x, mrb_value y)
   case MRB_TT_INTEGER:
     {
       mrb_int z = mrb_integer(y);
+      if (z == 0) mrb_int_zerodiv(mrb);
       if (mrb_int_mul_overflow(p1->denominator, z, &z)) rat_overflow(mrb);
       return rational_new_i(mrb, p1->numerator, z);
     }

src/numeric.c

@@ -160,7 +160,6 @@ int_div(mrb_state *mrb, mrb_value x)
 #endif
   mrb_int a = mrb_integer(x);
 
-  if (a == 0) return mrb_fixnum_value(0);
   if (mrb_integer_p(y)) {
     return mrb_div_int_value(mrb, a, mrb_integer(y));
   }