parse.y: else without rescue

* parse.y (bodystmt): [EXPERIMENTAL] make `else` without `rescue`
  a syntax error.  [DevelopersMeeting20180315Japan]

  https://bugs.ruby-lang.org/projects/ruby/wiki/DevelopersMeeting20180315Japan
  https://docs.google.com/document/d/1RT0ijSo8uJ4Awn3CEvuYkjH0TVeXSYgeAFNmVGYC3ak/edit#
  > * do-else-end
  >   https://twitter.com/joker1007/status/974173396006129664
  >   https://twitter.com/joker1007/status/974173641347756032
  >   https://twitter.com/joker1007/status/974176512554369027
  >   Will be SyntaxError in 2.6-preview2
  >   All of begin/do/def (experimental)

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62901 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 13 insertions, 5 deletions

diff --git a/spec/ruby/language/rescue_spec.rb b/spec/ruby/language/rescue_spec.rb
index b3de84468b..66a493cd34 100644
--- a/spec/ruby/language/rescue_spec.rb
+++ b/spec/ruby/language/rescue_spec.rb
@@ -195,18 +195,26 @@ describe "The rescue keyword" do
     ScratchPad.recorded.should == [:one, :else_ran, :ensure_ran, :outside_begin]
   end
 
-  it "will execute an else block even without rescue and ensure" do
-    lambda {
-      eval <<-ruby
+  else_without_rescue = lambda {
+    eval <<-ruby
         begin
           ScratchPad << :begin
         else
           ScratchPad << :else
         end
       ruby
-    }.should complain(/else without rescue is useless/)
+  }
+
+  ruby_version_is ""..."2.6" do
+    it "will execute an else block even without rescue and ensure" do
+      else_without_rescue.should complain(/else without rescue is useless/)
+
+      ScratchPad.recorded.should == [:begin, :else]
+    end
+  end
 
-    ScratchPad.recorded.should == [:begin, :else]
+  ruby_version_is "2.6" do
+    else_without_rescue.should raise_error(SyntaxError)
   end
 
   it "will not execute an else block if an exception was raised" do