SF patch #1438387, PEP 328: relative and absolute imports.

 - IMPORT_NAME takes an extra argument from the stack: the relativeness of
   the import. Only passed to __import__ when it's not -1.

 - __import__() takes an optional 5th argument for the same thing; it
   __defaults to -1 (old semantics: try relative, then absolute)

 - 'from . import name' imports name (be it module or regular attribute)
   from the current module's *package*. Likewise, 'from .module import name'
   will import name from a sibling to the current module.

 - Importing from outside a package is not allowed; 'from . import sys' in a
   toplevel module will not work, nor will 'from .. import sys' in a
   (single-level) package.

 - 'from __future__ import absolute_import' will turn on the new semantics
   for import and from-import: imports will be absolute, except for
   from-import with dots.

Includes tests for regular imports and importhooks, parser changes and a
NEWS item, but no compiler-package changes or documentation changes.

1 files changed, 17 insertions, 6 deletions

diff --git a/Python/ceval.c b/Python/ceval.c
index 2c2104e..3732f6d 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2023,13 +2023,24 @@ PyEval_EvalFrameEx(PyFrameObject *f, int throw)
 						"__import__ not found");
 				break;
 			}
+			v = POP();
 			u = TOP();
-			w = PyTuple_Pack(4,
-				    w,
-				    f->f_globals,
-				    f->f_locals == NULL ?
-					  Py_None : f->f_locals,
-				    u);
+			if (PyInt_AsLong(u) != -1 || PyErr_Occurred())
+				w = PyTuple_Pack(5,
+					    w,
+					    f->f_globals,
+					    f->f_locals == NULL ?
+						  Py_None : f->f_locals,
+					    v,
+					    u);
+			else
+				w = PyTuple_Pack(4,
+					    w,
+					    f->f_globals,
+					    f->f_locals == NULL ?
+						  Py_None : f->f_locals,
+					    v);
+			Py_DECREF(v);
 			Py_DECREF(u);
 			if (w == NULL) {
 				u = POP();