fix optional arguments in rhs

define optional arguments as argument variables in the rhs default
expressions, as same as mere assignment expressions.

Import ruby/ruby@01740f0c273c89f7bcff3d5014d73c8ff6fb1986

1 files changed, 17 insertions, 0 deletions

diff --git a/test/t/syntax.rb b/test/t/syntax.rb
index 2adfbc8ab..245c5c099 100644
--- a/test/t/syntax.rb
+++ b/test/t/syntax.rb
@@ -272,3 +272,20 @@ assert('method definition in cmdarg') do
   end
   true
 end
+
+assert('optional argument in the rhs default expressions') do
+  class OptArgInRHS
+    def foo
+      "method called"
+    end
+    def t(foo = foo)
+      foo
+    end
+    def t2(foo = foo())
+      foo
+    end
+  end
+  o = OptArgInRHS.new
+  assert_nil(o.t)
+  assert_equal("method called", o.t2)
+end