Fix for bug #661136

Lesson learned: kids should not be allowed to use API's starting
with an underscore :-/
zipimport in 2.3a1 is even more broken than I thought: I attemped
to _PyString_Resize a string created by PyString_FromStringAndSize,
which fails for strings with length 0 or 1 since the latter returns
an interned string in those cases. This would cause a SystemError
with empty source files (and no matching pyc) in the zip archive.
I rewrote the offending code to simply allocate a new buffer and
avoid _PyString_Resize altogether.
Added a test that would've caught the problem.

1 files changed, 8 insertions, 3 deletions

diff --git a/Lib/test/test_zipimport.py b/Lib/test/test_zipimport.py
index 5f6d8ef..3c790eb 100644
--- a/Lib/test/test_zipimport.py
+++ b/Lib/test/test_zipimport.py
@@ -56,9 +56,10 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
 
             mod = __import__(".".join(modules), globals(), locals(),
                              ["__dummy__"])
-            file = mod.get_file()
-            self.assertEquals(file, os.path.join(TEMP_ZIP,
-                              os.sep.join(modules) + expected_ext))
+            if expected_ext:
+                file = mod.get_file()
+                self.assertEquals(file, os.path.join(TEMP_ZIP,
+                                  os.sep.join(modules) + expected_ext))
         finally:
             z.close()
             os.remove(TEMP_ZIP)
@@ -101,6 +102,10 @@ class UncompressedZipImportTestCase(ImportHooksBaseTestCase):
                  TESTMOD + pyc_ext: (NOW, test_pyc)}
         self.doTest(pyc_ext, files, TESTMOD)
 
+    def testEmptyPy(self):
+        files = {TESTMOD + ".py": (NOW, "")}
+        self.doTest(None, files, TESTMOD)
+
     def testBadMagic(self):
         # make pyc magic word invalid, forcing loading from .py
         m0 = ord(test_pyc[0])