bookmarks: check HG_PENDING strictly Before this patch, checking HG_PENDING in bookmarks.py might cause unintentional reading unrelated '.hg/bookmarks.pending' in, because it just examines existence of HG_PENDING environment variable. This patch uses txnutil.trypending() to check HG_PENDING strictly. This patch also changes share extension. Enabling share extension (+ bookmark sharing) makes bookmarks._getbkfile() receive repo to be shared (= "srcrepo"). On the other hand, HG_PENDING always refers current working repo (= "currepo"), and bookmarks.pending is written only into currepo. Therefore, we should try to read .hg/bookmarks.pending of currepo in at first. If it doesn't exist, we try to read .hg/bookmarks of srcrepo in. Even after this patch, an external hook spawned in currepo can't see pending changes in currepo via srcrepo, even though such changes become visible after closing transaction, because there is no easy and cheap way to know existence of pending changes in currepo via srcrepo. Please see https://www.mercurial-scm.org/wiki/SharedRepository, too. BTW, this patch may cause failure of bisect in the repository of Mercurial itself, if examination at bisecting assumes that an external hook can see all pending changes while nested transactions across repositories. This invisibility issue will be fixed by subsequent patch, which allows HG_PENDING to refer multiple repositories.