rational.c: convert a numerator to rational before calling fdiv in Kernel.Rational() (#3702)

mrkn · web-flow · commit 69837229d748 · 2020-10-26T18:43:30.000+09:00
This makes `Rational(BigDecimal(1), 60) == Rational(1, 60)`.
[Bug #16518]
diff --git a/rational.c b/rational.c
@@ -2673,8 +2673,16 @@ nurat_convert(VALUE klass, VALUE numv, VALUE denv, int raise)
             }
         }
         if ((k_numeric_p(a1) && k_numeric_p(a2)) &&
-                (!f_integer_p(a1) || !f_integer_p(a2)))
+                (!f_integer_p(a1) || !f_integer_p(a2))) {
+            VALUE tmp = rb_protect(to_rational, a1, &state);
+            if (!state) {
+                a1 = tmp;
+            }
+            else {
+                rb_set_errinfo(Qnil);
+            }
             return f_div(a1, a2);
+        }
     }
 
     a1 = nurat_int_value(a1);
diff --git a/test/ruby/test_rational.rb b/test/ruby/test_rational.rb
@@ -165,6 +165,14 @@ def o.to_r; raise; end
     if (1.0/0).infinite?
       assert_raise(FloatDomainError){Rational(1.0/0)}
     end
+
+    bug16518 = "[ruby-core:96942] [Bug #16518]"
+    cls = Class.new(Numeric) do
+      def /(y); 42; end
+      def to_r; 1r; end
+      def to_int; 1; end
+    end
+    assert_equal(1/2r, Rational(cls.new, 2))
   end
 
   def test_attr

Original file line number	Diff line number	Diff line change
`@@ -2673,8 +2673,16 @@ nurat_convert(VALUE klass, VALUE numv, VALUE denv, int raise)`
`2673`	`2673`	`}`
`2674`	`2674`	`}`
`2675`	`2675`	`if ((k_numeric_p(a1) && k_numeric_p(a2)) &&`
`2676`		`- (!f_integer_p(a1) \|\| !f_integer_p(a2)))`
	`2676`	`+ (!f_integer_p(a1) \|\| !f_integer_p(a2))) {`
	`2677`	`+ VALUE tmp = rb_protect(to_rational, a1, &state);`
	`2678`	`+ if (!state) {`
	`2679`	`+ a1 = tmp;`
	`2680`	`+ }`
	`2681`	`+ else {`
	`2682`	`+ rb_set_errinfo(Qnil);`
	`2683`	`+ }`
`2677`	`2684`	`return f_div(a1, a2);`
	`2685`	`+ }`
`2678`	`2686`	`}`
`2679`	`2687`
`2680`	`2688`	`a1 = nurat_int_value(a1);`