parse.y: rescue/else/ensure in do-end

* parse.y (do_body): allow rescue/else/ensure inside do/end
  blocks.  [Feature #12906]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57376 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

NEWS

@@ -16,6 +16,8 @@ with all sufficient information, see the ChangeLog file or Redmine
 
 * Top-level constant look-up is removed.  [Feature #11547]
 
+* rescue/else/ensure are allowed inside do/end blocks.  [Feature #12906]
+
 === Core classes updates (outstanding ones only)
 
 === Stdlib updates (outstanding ones only)

parse.y

@@ -3763,7 +3763,7 @@ brace_body	: {$<vars>$ = dyna_push();}
 
 do_body 	: {$<vars>$ = dyna_push();}
 		  {$<val>$ = cmdarg_stack; CMDARG_SET(0);}
-		  opt_block_param compstmt
+		  opt_block_param bodystmt
 		    {
 			$$ = new_do_body($3, $4);
 			dyna_pop($<vars>1);

test/ruby/test_syntax.rb

@@ -979,6 +979,73 @@ eom
     assert_in_out_err(%w[-e redo], "", [], /^-e:1: /)
   end
 
+  def test_rescue_do_end_raised
+    result = []
+    assert_raise(RuntimeError) do
+      eval("#{<<-"begin;"}\n#{<<-"end;"}")
+      begin;
+        tap do
+          result << :begin
+          raise "An exception occured!"
+        ensure
+          result << :ensure
+        end
+      end;
+    end
+    assert_equal([:begin, :ensure], result)
+  end
+
+  def test_rescue_do_end_rescued
+    result = []
+    assert_nothing_raised(RuntimeError) do
+      eval("#{<<-"begin;"}\n#{<<-"end;"}")
+      begin;
+        tap do
+          result << :begin
+          raise "An exception occured!"
+        rescue
+          result << :rescue
+        else
+          result << :else
+        ensure
+          result << :ensure
+        end
+      end;
+    end
+    assert_equal([:begin, :rescue, :ensure], result)
+  end
+
+  def test_rescue_do_end_no_raise
+    result = []
+    assert_nothing_raised(RuntimeError) do
+      eval("#{<<-"begin;"}\n#{<<-"end;"}")
+      begin;
+        tap do
+          result << :begin
+        rescue
+          result << :rescue
+        else
+          result << :else
+        ensure
+          result << :ensure
+        end
+      end;
+    end
+    assert_equal([:begin, :else, :ensure], result)
+  end
+
+  def test_rescue_do_end_ensure_result
+    result = eval("#{<<-"begin;"}\n#{<<-"end;"}")
+    begin;
+      proc do
+        :begin
+      ensure
+        :ensure
+      end.call
+    end;
+    assert_equal(:begin, result)
+  end
+
   private
 
   def not_label(x) @result = x; @not_label ||= nil end