array.c: check if numeric

* array.c (finish_exact_sum): add 0 and the initial value to check
  if the latter is numeric.  [ruby-core:79572] [Bug #13222]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57651 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 9 insertions, 3 deletions

diff --git a/array.c b/array.c
index d9d6bdbf87..182046856c 100644
--- a/array.c
+++ b/array.c
@@ -5734,7 +5734,7 @@ rb_ary_dig(int argc, VALUE *argv, VALUE self)
 }
 
 static inline VALUE
-finish_exact_sum(long n, VALUE r, VALUE v)
+finish_exact_sum(long n, VALUE r, VALUE v, int z)
 {
     if (n != 0)
         v = rb_fix_plus(LONG2FIX(n), v);
@@ -5747,6 +5747,9 @@ finish_exact_sum(long n, VALUE r, VALUE v)
 	else
 	    v = rb_rational_plus(r, v);
     }
+    else if (!n && z) {
+        v = rb_fix_plus(LONG2FIX(0), v);
+    }
     return v;
 }
 
@@ -5831,11 +5834,11 @@ rb_ary_sum(int argc, VALUE *argv, VALUE ary)
         else
             goto not_exact;
     }
-    v = finish_exact_sum(n, r, v);
+    v = finish_exact_sum(n, r, v, argc!=0);
     return v;
 
   not_exact:
-    v = finish_exact_sum(n, r, v);
+    v = finish_exact_sum(n, r, v, i!=0);
 
     if (RB_FLOAT_TYPE_P(e)) {
         /*
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 08100142f8..b0be0b4a87 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -2838,6 +2838,9 @@ class TestArray < Test::Unit::TestCase
     assert_equal("abc", ["a", "b", "c"].sum(""))
     assert_equal([1, [2], 3], [[1], [[2]], [3]].sum([]))
 
+    assert_raise(TypeError) {[0].sum("")}
+    assert_raise(TypeError) {[1].sum("")}
+
     assert_separately(%w[-rmathn], <<-EOS, ignore_stderr: true)
       assert_equal(6, [1r, 2, 3r].sum)
     EOS