--- a/mercurial/transaction.py	Fri Feb 11 22:24:10 2011 +0800
+++ b/mercurial/transaction.py	Fri Dec 24 15:23:01 2010 +0100
@@ -27,13 +27,17 @@
     for f, o, ignore in entries:
         if o or not unlink:
             try:
-                opener(f, 'a').truncate(o)
+                fp = opener(f, 'a')
+                fp.truncate(o)
+                fp.close()
             except IOError:
                 report(_("failed to truncate %s\n") % f)
                 raise
         else:
             try:
-                fn = opener(f).name
+                fp = opener(f)
+                fn = fp.name
+                fp.close()
                 os.unlink(fn)
             except (IOError, OSError), inst:
                 if inst.errno != errno.ENOENT:
@@ -169,7 +173,10 @@
 def rollback(opener, file, report):
     entries = []
 
-    for l in open(file).readlines():
+    fp = open(file)
+    lines = fp.readlines()
+    fp.close()
+    for l in lines:
         f, o = l.split('\0')
         entries.append((f, int(o), None))