bug: qpush loses loses file executable permissions

[Armando Singer]

Our developers have routinely been losing the executable bit (and
possibly all non-default permissions) on files and propogating them to
our remote repo. We've narrowed it down to qpush:

$ hg init test && cd test
$ hg qinit && hg qnew -m "Executable patch test" exec
$ echo "test" > foo  # can't use touch, qpush breaks
$ chmod 777 foo && hg add && hg qrefresh
$ hg manifest
47e1a02b8587f450522a1cb73c3ef8ed21f2f923 755 foo
$ hg qpop
Patch queue now empty
$ hg qpush
applying exec
Now at: exec
$ hg manifest
47e1a02b8587f450522a1cb73c3ef8ed21f2f923 644 foo
$ ls -l foo
-rw-rw-r-- 1 asinger devel 5 Nov  2 13:10 foo

It it ok if I log a bug for this, as well as the qpush bug with empty
files? These are pretty major for us because we are relying on MQ
(perhaps prematurely).

This has been happening at least on a few of the latest revisions,
including the current tip:

$ hg version
Mercurial Distributed SCM (version a27d90c9336e)

Thank you,
Armando