sqliterevmap: break ".hashes()" cycle in a safer way The `fromsvn()` revset implementation could cause weakref error when using sqliterevmap like: File "hgsubversion/util.py", line 357, in <lambda> return subset.filter(lambda r: tonode(r) in hashes) File "hgsubversion/maps.py", line 542, in __contains__ return self.get(key) != None File "hgsubversion/maps.py", line 533, in get for row in self.revmap._query( ReferenceError: weakly-referenced object no longer exists Basically the seemingly harmless assignment could break surprisingly: # dangerous: `hashes` does not have a reference of `meta.revmap` and may # become unavailable after `meta`, `revmap` being released by refcount. hashes = meta.revmap.hashes() The above syntax is nice to support while avoiding cycles is also nice. This patch removes `revmap._hashes` so the revmap no longer owns a reference of a `ReverseRevMap` object so the `ReverseRevMap` object no longer needs to use weakref for `self.revmap`. This could actually be caught by `comprehensive/test_sqlite_revmap.py`. I was not careful enough verifying the "fromsvn()" patch.

import os
import sys
import test_util
import unittest

from mercurial import hg
from mercurial import commands
from mercurial import util


class TestSvnPreCommitHooks(test_util.TestBase):
    def setUp(self):
        super(TestSvnPreCommitHooks, self).setUp()
        self.repo_path = self.load_and_fetch('single_rev.svndump')[1]
        # creating pre-commit hook that doesn't allow any commit
        hook_file_name = os.path.join(
			self.repo_path, 'hooks', 'pre-commit'
        )
        hook_file = open(hook_file_name, 'w')
        hook_file.write(
        	'#!/bin/sh\n'
        	'echo "Commits are not allowed" >&2; exit 1;\n'
        )
        hook_file.close()
        os.chmod(hook_file_name, 0755)

    def test_push_with_pre_commit_hooks(self):
        changes = [('narf/a', 'narf/a', 'ohai',),
                   ]
        self.commitchanges(changes)
        self.assertRaises(util.Abort, self.pushrevisions)