add dirstate._dirtypl variable Theoretically, it's possible to forget modified dirstate parents by doing: dirstate.invalidate() dirstate.setparents(p1, p2) dirstate._map The final access to _map should call _read(), which will unconditionally overwrite dirstate._pl. This doesn't actually happen right now because invalidate accidentally ends up rebuilding dirstate._map.

#!/bin/sh
hg init
echo This is file a1 > a
hg add a
hg commit -m "commit #0" -d "1000000 0"
ls
echo This is file b1 > b
hg add b
hg commit -m "commit #1" -d "1000000 0"
hg co 0
# B should disappear
ls