Fix SF bug #1458903 with AST compiler.

def foo((x)): was getting recognized as requiring tuple unpacking
which is not correct.

Add tests for this case and the proper way to unpack a tuple of one:
	def foo((x,)):

test_inpsect was incorrect before.  I'm not sure why it was passing,
but that has been corrected with a test for both functions above.
This means the test (and therefore inspect.getargspec()) are broken in 2.4.

Lib/test/test_grammar.py

@@ -255,6 +255,10 @@ d22v(1, 2, 3, 4, 5)
 d22v(*(1, 2, 3, 4))
 d22v(1, 2, *(3, 4, 5))
 d22v(1, *(2, 3), **{'d': 4})
+def d31v((x)): pass
+d31v(1)
+def d32v((x,)): pass
+d32v((1,))
 
 ### lambdef: 'lambda' [varargslist] ':' test
 print 'lambdef'

Lib/test/test_inspect.py

@@ -304,10 +304,12 @@ class TestClassesAndFunctions(unittest.TestCase):
         self.assertArgSpecEquals(A.m, ['self'])
 
     def test_getargspec_sublistofone(self):
-        def sublistOfOne((foo)): return 1
-
+        def sublistOfOne((foo,)): return 1
         self.assertArgSpecEquals(sublistOfOne, [['foo']])
 
+        def fakeSublistOfOne((foo)): return 1
+        self.assertArgSpecEquals(fakeSublistOfOne, ['foo'])
+
     def test_classify_oldstyle(self):
         class A:
             def s(): pass

Python/ast.c

@@ -645,10 +645,17 @@ ast_for_arguments(struct compiling *c, const node *n)
 		    goto error;
 		}
                 if (NCH(ch) == 3) {
-                    asdl_seq_SET(args, k++, 
-                                    compiler_complex_args(c, CHILD(ch, 1))); 
-		}
-                else if (TYPE(CHILD(ch, 0)) == NAME) {
+		    ch = CHILD(ch, 1);
+		    /* def foo((x)): is not complex, special case. */
+		    if (NCH(ch) != 1) {
+			/* We have complex arguments, setup for unpacking. */
+			asdl_seq_SET(args, k++, compiler_complex_args(c, ch));
+		    } else {
+			/* def foo((x)): setup for checking NAME below. */
+			ch = CHILD(ch, 0);
+		    }
+                }
+                if (TYPE(CHILD(ch, 0)) == NAME) {
 		    expr_ty name;
 		    if (!strcmp(STR(CHILD(ch, 0)), "None")) {
 			    ast_error(CHILD(ch, 0), "assignment to None");