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.

#!/bin/sh
#
# Create emptyrepo2.svndump
#
# The generated repository contains a sequence of empty revisions
# created with a combination of svnsync and filtering

mkdir temp
cd temp

mkdir project-orig
cd project-orig
mkdir -p sub/trunk other
echo a > other/a
cd ..

svnadmin create testrepo
svnurl=file://`pwd`/testrepo
svn import project-orig $svnurl -m init

svn co $svnurl project
cd project
echo a >> other/a
svn ci -m othera
echo a >> other/a
svn ci -m othera2
echo b > sub/trunk/a
svn add sub/trunk/a
svn ci -m adda
cd ..

svnadmin create testrepo2
cat > testrepo2/hooks/pre-revprop-change <<EOF
#!/bin/sh
exit 0
EOF
chmod +x testrepo2/hooks/pre-revprop-change

svnurl2=file://`pwd`/testrepo2
svnsync init --username svnsync $svnurl2 $svnurl/sub
svnsync sync $svnurl2

svnadmin dump testrepo2 > ../emptyrepo2.svndump