object.c: raise TypeError

* object.c (rb_obj_dig): raise TypeError if an element does not
  have #dig method.  [ruby-core:71798] [Bug #11762]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53058 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sat Dec 12 18:52:26 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* object.c (rb_obj_dig): raise TypeError if an element does not
+	  have #dig method.  [ruby-core:71798] [Bug #11762]
+
 Sat Dec 12 17:59:07 2015  Yuichiro Kaneko  <yui-knk@ruby-lang.org>
 
 	* test/ruby/test_regexp.rb: Add test cases for `$KCODE` and `$=` warning

object.c

@@ -3169,12 +3169,22 @@ dig_basic_p(VALUE obj, struct dig_method *cache)
     return cache->basic;
 }
 
+static void
+no_dig_method(int found, VALUE recv, ID mid, int argc, const VALUE *argv, VALUE data)
+{
+    if (!found) {
+	rb_raise(rb_eTypeError, "%"PRIsVALUE" does not have #dig method",
+		 CLASS_OF(data));
+    }
+}
+
 VALUE
 rb_obj_dig(int argc, VALUE *argv, VALUE obj, VALUE notfound)
 {
     struct dig_method hash = {Qnil}, ary = {Qnil}, strt = {Qnil};
 
     for (; argc > 0; ++argv, --argc) {
+	if (NIL_P(obj)) return notfound;
 	if (!SPECIAL_CONST_P(obj)) {
 	    switch (BUILTIN_TYPE(obj)) {
 	      case T_HASH:
@@ -3197,7 +3207,8 @@ rb_obj_dig(int argc, VALUE *argv, VALUE obj, VALUE notfound)
 		break;
 	    }
 	}
-	return rb_check_funcall_default(obj, id_dig, argc, argv, notfound);
+	return rb_check_funcall_with_hook(obj, id_dig, argc, argv,
+					  no_dig_method, obj);
     }
     return obj;
 }

test/ruby/test_array.rb

@@ -2654,7 +2654,8 @@ class TestArray < Test::Unit::TestCase
   def test_dig
     h = @cls[@cls[{a: 1}], 0]
     assert_equal(1, h.dig(0, 0, :a))
-    assert_nil(h.dig(1, 0))
+    assert_nil(h.dig(2, 0))
+    assert_raise(TypeError) {h.dig(1, 0)}
   end
 
   private

test/ruby/test_hash.rb

@@ -1305,7 +1305,8 @@ class TestHash < Test::Unit::TestCase
   def test_dig
     h = @cls[a: @cls[b: [1, 2, 3]], c: 4]
     assert_equal(1, h.dig(:a, :b, 0))
-    assert_nil(h.dig(:c, 1))
+    assert_nil(h.dig(:b, 1))
+    assert_raise(TypeError) {h.dig(:c, 1)}
     o = Object.new
     def o.dig(*args)
       {dug: args}