diff -r cbd458228a96 -r d821918e3bee mercurial/appendfile.py
--- a/mercurial/appendfile.py	Sun Apr 30 19:30:59 2006 +0200
+++ b/mercurial/appendfile.py	Sun Apr 30 21:11:22 2006 +0200
@@ -38,7 +38,7 @@
             self.tmpname = tmpname
             self.tmpfp = open(self.tmpname, 'ab+')
         else:
-            fd, self.tmpname = tempfile.mkstemp()
+            fd, self.tmpname = tempfile.mkstemp(prefix="hg-appendfile-")
             self.tmpfp = os.fdopen(fd, 'ab+')
         self.realfp = fp
         self.offset = fp.tell()