random.c: increase limit for generic rand

* random.c (rb_random_ulong_limited): limit is inclusive, but generic
  rand method should return a number less than it, so increase for the
  difference.  [ruby-core:52779] [Bug #7935]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39466 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 8 insertions, 0 deletions

diff --git a/test/ruby/test_rand.rb b/test/ruby/test_rand.rb
index 9fabfc607f..611e9f57a0 100644
--- a/test/ruby/test_rand.rb
+++ b/test/ruby/test_rand.rb
@@ -528,5 +528,13 @@ END
     def (gen = Object.new).rand(*) -1 end
     e = assert_raise(RangeError) {[1,2,3].sample(random: gen)}
     assert_match(/small -1\z/, e.message, bug7903)
+
+    bug7935 = '[ruby-core:52779] [Bug #7935]'
+    class << (gen = Object.new)
+      def rand(limit) @limit = limit; 0 end
+      attr_reader :limit
+    end
+    [1, 2].sample(1, random: gen)
+    assert_equal(2, gen.limit, bug7935)
   end
 end