shelve: disallow commit while unshelve is in progress Before this patch, commit is allowed even while unshelve is in progress. In the other hand, "hg unshelve --abort" and "hg unshelve --continue" check whether parent revisions of the working directory have changed or not since last "hg unshelve", and abort without clearing state for unshelve in progress if they have. This causes that accidental commit makes clearing state for unshelve difficult in ordinary ways. This patch disallows commit while unshelve is in progress for consistency.