parse.y: chained assignments

* parse.y (command_asgn, arg): fix syntax errors with chained
  assignment with op assign.  [Bug #12669]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55888 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sat Aug 13 11:10:08 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* parse.y (command_asgn, arg): fix syntax errors with chained
+	  assignment with op assign.  [Bug #12669]
+
 Sat Aug 13 10:52:19 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (stmt, arg): rescue modifier in command op assignment

parse.y

@@ -1284,6 +1284,28 @@ stmt		: keyword_alias fitem {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fitem
 			$$ = dispatch2(massign, $1, $3);
 		    %*/
 		    }
+		| lhs '=' mrhs
+		    {
+			value_expr($3);
+			$$ = node_assign($1, $3);
+		    }
+		| mlhs '=' mrhs_arg
+		    {
+		    /*%%%*/
+			$1->nd_value = $3;
+			$$ = $1;
+		    /*%
+			$$ = dispatch2(massign, $1, $3);
+		    %*/
+		    }
+		| expr
+		;
+
+command_asgn	: lhs '=' command_rhs
+		    {
+			value_expr($3);
+			$$ = node_assign($1, $3);
+		    }
 		| var_lhs tOP_ASGN command_rhs
 		    {
 			value_expr($3);
@@ -1335,28 +1357,6 @@ stmt		: keyword_alias fitem {SET_LEX_STATE(EXPR_FNAME|EXPR_FITEM);} fitem
 			$1 = var_field($1);
 			$$ = backref_assign_error($1, node_assign($1, $3));
 		    }
-		| lhs '=' mrhs
-		    {
-			value_expr($3);
-			$$ = node_assign($1, $3);
-		    }
-		| mlhs '=' mrhs_arg
-		    {
-		    /*%%%*/
-			$1->nd_value = $3;
-			$$ = $1;
-		    /*%
-			$$ = dispatch2(massign, $1, $3);
-		    %*/
-		    }
-		| expr
-		;
-
-command_asgn	: lhs '=' command_rhs
-		    {
-			value_expr($3);
-			$$ = node_assign($1, $3);
-		    }
 		;
 
 command_rhs	: command_call   %prec tOP_ASGN

test/ruby/test_assignment.rb

@@ -771,4 +771,14 @@ class TestAssignmentGen < Test::Unit::TestCase
     h[*k], = ["ok", "ng"]
     assert_equal("ok", h[:key], bug11970)
   end
+
+  def test_chainged_assign_command
+    all_assertions do |a|
+      asgn = %w'= +='
+      asgn.product(asgn) do |a1, a2|
+        stmt = "a #{a1} b #{a2} raise 'x'"
+        a.for(stmt) {assert_valid_syntax(stmt)}
+      end
+    end
+  end
 end