Merged revisions 88403 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/py3k

Test not backported since they depend on 3.x quirks.  Not
easy to rewrite them for 2.7.

........
  r88403 | r.david.murray | 2011-02-11 17:47:17 -0500 (Fri, 11 Feb 2011) | 3 lines

  #11116: roll back on error during add so mailbox isn't left corrupted.
........

Lib/mailbox.py

@@ -253,7 +253,10 @@ class Maildir(Mailbox):
         tmp_file = self._create_tmp()
         try:
             self._dump_message(message, tmp_file)
-        finally:
+        except BaseException:
+            tmp_file.close()
+            os.remove(tmp_file.name)
+            raise
         _sync_close(tmp_file)
         if isinstance(message, MaildirMessage):
             subdir = message.get_subdir()
@@ -700,9 +703,14 @@ class _singlefileMailbox(Mailbox):
     def _append_message(self, message):
         """Append message to mailbox and return (start, stop) offsets."""
         self._file.seek(0, 2)
+        before = self._file.tell()
+        try:
             self._pre_message_hook(self._file)
             offsets = self._install_message(message)
             self._post_message_hook(self._file)
+        except BaseException:
+            self._file.truncate(before)
+            raise
         self._file.flush()
         self._file_length = self._file.tell()  # Record current length of mailbox
         return offsets
@@ -871,8 +879,12 @@ class MH(Mailbox):
         try:
             if self._locked:
                 _lock_file(f)
+            try:
                 try:
                     self._dump_message(message, f)
+                except BaseException:
+                    os.remove(new_path)
+                    raise
                 if isinstance(message, MHMessage):
                     self._dump_sequences(message, new_key)
             finally:

Misc/NEWS

@@ -37,6 +37,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #11116: any error during addition of a message to a mailbox now causes
+  a rollback, instead of leaving the mailbox partially modified.
+
 - Issue #8275: Fix passing of callback arguments with ctypes under Win64.
   Patch by Stan Mihai.