[2to3] Bug converting import

[Christian Heimes]

Helmut Jarausch wrote:
> Now, when I invoke Master.py  I get
> 
> Traceback (most recent call last):
>   File "Master.py", line 2, in <module>
> from . import Slave
> ValueError: Attempted relative import in non-package
> 
> 
> thanks for looking into it,

The cause of the bug is in fixes/fix_import.py
probably_a_local_import(). The function doesn't check if
dirname(file_path) is a package.

This patch should fix the bug:

Index: Lib/lib2to3/fixes/fix_import.py
===================================================================
--- Lib/lib2to3/fixes/fix_import.py     (Revision 64490)
+++ Lib/lib2to3/fixes/fix_import.py     (Arbeitskopie)
@@ -53,8 +53,13 @@
     # Must be stripped because the right space is included by the parser
     imp_name = imp_name.split('.', 1)[0].strip()
     base_path = dirname(file_path)
-    base_path = join(base_path, imp_name)
-    for ext in ['.py', pathsep, '.pyc', '.so', '.sl', '.pyd']:
-        if exists(base_path + ext):
+    base_name = join(base_path, imp_name)
+    base_init = join(base_path, "__init__")
+    exts = ['.py', pathsep, '.pyc', 'pyo', '.so', '.sl', '.pyd']
+    if not any(exists(base_init + ext) for ext in exts):
+        # not a package
+        return False
+    if any(exists(base_name + ext) for ext in exts):
             return True
     return False