fileset: add function to switch revision where fileset will be evaluated
If the subset isn't filtered yet, i.e. if fullmatchctx, the new subset is
recalculated from scratch. Otherwise, it is narrowed by the existing subset.
$ cat > engine.py << EOF
>
> from mercurial import templater
>
> class mytemplater(object):
> def __init__(self, loader, filters, defaults, aliases):
> self.loader = loader
>
> def process(self, t, map):
> tmpl = self.loader(t)
> for k, v in map.iteritems():
> if k in ('templ', 'ctx', 'repo', 'revcache', 'cache'):
> continue
> if hasattr(v, '__call__'):
> v = v(**map)
> v = templater.stringify(v)
> tmpl = tmpl.replace('{{%s}}' % k, v)
> yield tmpl
>
> templater.engines['my'] = mytemplater
> EOF
$ hg init test
$ echo '[extensions]' > test/.hg/hgrc
$ echo "engine = `pwd`/engine.py" >> test/.hg/hgrc
$ cd test
$ cat > mymap << EOF
> changeset = my:changeset.txt
> EOF
$ cat > changeset.txt << EOF
> {{rev}} {{node}} {{author}}
> EOF
$ hg ci -Ama
adding changeset.txt
adding mymap
$ hg log --style=./mymap
0 97e5f848f0936960273bbf75be6388cd0350a32b test
$ cat > changeset.txt << EOF
> {{p1rev}} {{p1node}} {{p2rev}} {{p2node}}
> EOF
$ hg ci -Ama
$ hg log --style=./mymap
0 97e5f848f0936960273bbf75be6388cd0350a32b -1 0000000000000000000000000000000000000000
-1 0000000000000000000000000000000000000000 -1 0000000000000000000000000000000000000000
invalid engine type:
$ echo 'changeset = unknown:changeset.txt' > unknownenginemap
$ hg log --style=./unknownenginemap
abort: invalid template engine: unknown
[255]
$ cd ..