shelve: restore shelved dirstate explicitly after aborting transaction Before this patch, "hg shelve" uses aborting a current transaction to discard temporary changes while shelving. This assumes that dirstate changes in a transaction scope are kept even after aborting it. But this assumption will be broken by "transactional dirstate". See the wiki page below for detail about it. https://mercurial.selenic.com/wiki/DirstateTransactionPlan This patch explicitly saves shelved dirstate just before aborting current transaction, and restore dirstate with it after aborting by utility function '_aborttransaction()' added by previous patch. This patch replaces 'if tr: tr.abort()' by 'lockmod.release(tr)', because the former is already done in '_aborttransaction()' (and the latter has no effect), if current transaction is aborted in it successfully. Otherwise, the latter is enough to trigger aborting.