transaction: use posixfile and unlink from util

transaction: use posixfile and unlink from util

instead of open() and os.unlink()

Avoids potential issues with file access on Windows (e.g. AV-scanners).

--- a/mercurial/transaction.py	Mon Feb 14 23:59:21 2011 -0600
+++ b/mercurial/transaction.py	Tue Feb 15 14:41:49 2011 +0100
@@ -13,7 +13,7 @@
 
 from i18n import _
 import os, errno
-import error
+import error, util
 
 def active(func):
     def _active(self, *args, **kwds):
@@ -38,11 +38,11 @@
                 fp = opener(f)
                 fn = fp.name
                 fp.close()
-                os.unlink(fn)
+                util.unlink(fn)
             except (IOError, OSError), inst:
                 if inst.errno != errno.ENOENT:
                     raise
-    os.unlink(journal)
+    util.unlink(journal)
 
 class transaction(object):
     def __init__(self, report, opener, journal, after=None, createmode=None):
@@ -56,7 +56,7 @@
         self.journal = journal
         self._queue = []
 
-        self.file = open(self.journal, "w")
+        self.file = util.posixfile(self.journal, "w")
         if createmode is not None:
             os.chmod(self.journal, createmode & 0666)
 
@@ -137,7 +137,7 @@
         if self.after:
             self.after()
         if os.path.isfile(self.journal):
-            os.unlink(self.journal)
+            util.unlink(self.journal)
         self.journal = None
 
     @active
@@ -155,7 +155,7 @@
         try:
             if not self.entries:
                 if self.journal:
-                    os.unlink(self.journal)
+                    util.unlink(self.journal)
                 return
 
             self.report(_("transaction abort!\n"))
@@ -173,7 +173,7 @@
 def rollback(opener, file, report):
     entries = []
 
-    fp = open(file)
+    fp = util.posixfile(file)
     lines = fp.readlines()
     fp.close()
     for l in lines: