Patch for http://bugs.python.org/issue18111

decorator-syntax.patch

diff -r 1e79ca2bc494 Doc/reference/compound_stmts.rst
--- a/Doc/reference/compound_stmts.rst	Wed Nov 20 11:53:31 2013 -0800
+++ b/Doc/reference/compound_stmts.rst	Wed Nov 20 20:23:32 2013 -0500
@@ -442,7 +442,7 @@
 .. productionlist::
    funcdef: [`decorators`] "def" `funcname` "(" [`parameter_list`] ")" ["->" `expression`] ":" `suite`
    decorators: `decorator`+
-   decorator: "@" `dotted_name` ["(" [`parameter_list` [","]] ")"] NEWLINE
+   decorator: "@" `expression` NEWLINE
    dotted_name: `identifier` ("." `identifier`)*
    parameter_list: (`defparameter` ",")*
                  : ( "*" [`parameter`] ("," `defparameter`)* ["," "**" `parameter`]
diff -r 1e79ca2bc494 Grammar/Grammar
--- a/Grammar/Grammar	Wed Nov 20 11:53:31 2013 -0800
+++ b/Grammar/Grammar	Wed Nov 20 20:23:32 2013 -0500
@@ -19,7 +19,7 @@
 file_input: (NEWLINE | stmt)* ENDMARKER
 eval_input: testlist NEWLINE* ENDMARKER
 
-decorator: '@' dotted_name [ '(' [arglist] ')' ] NEWLINE
+decorator: '@' testlist NEWLINE
 decorators: decorator+
 decorated: decorators (classdef | funcdef)
 funcdef: 'def' NAME parameters ['->' test] ':' suite
diff -r 1e79ca2bc494 Lib/test/test_decorators.py
--- a/Lib/test/test_decorators.py	Wed Nov 20 11:53:31 2013 -0800
+++ b/Lib/test/test_decorators.py	Wed Nov 20 20:23:32 2013 -0500
@@ -90,9 +90,30 @@
         self.assertEqual(foo(), 42)
         self.assertEqual(foo.author, 'Cleese')
 
+     def test_chained(self):
+         def d1():
+             class d2:
+                 def d3(self, f):
+                     return f
+         @d1().d2().d3
+         def foo(): return 42
+         self.assertEqual(foo(), 42)
+ 
+     def test_conditional(self):
+         def d1(f): return f
+         def d2(f): return None
+         @(d1 if True else d2)
+         def foo(): return 42
+         self.assertEqual(foo(), 42)
+ 
+     def test_lambda(self):
+         @(lambda f: f)
+         def foo(): return 42
+         self.assertEqual(foo(), 42)
+
     def test_argforms(self):
-        # A few tests of argument passing, as we use restricted form
-        # of expressions for decorators.
+        # A few tests of argument passing; note that we no longer
+        # restrict decorators to just this form.
 
         def noteargs(*args, **kwds):
             def decorate(func):
@@ -152,15 +173,6 @@
         self.assertEqual(counts['double'], 4)
 
     def test_errors(self):
-        # Test syntax restrictions - these are all compile-time errors:
-        #
-        for expr in [ "1+2", "x[3]", "(1, 2)" ]:
-            # Sanity check: is expr is a valid expression by itself?
-            compile(expr, "testexpr", "exec")
-
-            codestr = "@%s\ndef f(): pass" % expr
-            self.assertRaises(SyntaxError, compile, codestr, "test", "exec")
-
         # You can't put multiple decorators on a single line:
         #
         self.assertRaises(SyntaxError, compile,
diff -r 1e79ca2bc494 Modules/parsermodule.c
--- a/Modules/parsermodule.c	Wed Nov 20 11:53:31 2013 -0800
+++ b/Modules/parsermodule.c	Wed Nov 20 20:23:32 2013 -0500
@@ -2541,7 +2541,7 @@
     ok = (validate_ntype(tree, decorator) &&
           (nch == 3 || nch == 5 || nch == 6) &&
           validate_at(CHILD(tree, 0)) &&
-          validate_dotted_name(CHILD(tree, 1)) &&
+          validate_testlist(CHILD(tree, 1)) &&
           validate_newline(RCHILD(tree, -1)));
 
     if (ok && nch != 3) {
diff -r 1e79ca2bc494 Python/ast.c
--- a/Python/ast.c	Wed Nov 20 11:53:31 2013 -0800
+++ b/Python/ast.c	Wed Nov 20 20:23:32 2013 -0500
@@ -1429,7 +1429,7 @@
     REQ(CHILD(n, 0), AT);
     REQ(RCHILD(n, -1), NEWLINE);
 
-    name_expr = ast_for_dotted_name(c, CHILD(n, 1));
+    name_expr = ast_for_testlist(c, CHILD(n, 1));
     if (!name_expr)
         return NULL;