help: move rst formatting of help documents into help.py This slight refactor will help me improve the 'unknown command' experience in our new glorious pager future.

outgoing: avoid running pager until we're actually showing changes Consistent with the new behavior of incoming in the previous patch.

incoming: delay pager activation until right before printing changes This prevents authentication and other brief status messages from being paged.

histedit: modify rollup to discard date from the rollup commit (issue4820) This change adjusts and documents the new behaviour of 'roll'. It now fits nicely with the behaviour of 'commit --amend' and the 'edit' action, by discarding the date as well as the commit message of the second commit. Previously it used the later date, like 'fold', but this often wasn't desirable, for example, in the common use case of using 'roll' to add forgotten changes to a changeset (because 'hg add' was previously forgotten or not all changes were identified while using 'hg record').

histedit: improve documentation and behaviour of dates This clarifies in the histedit documentation that the 'edit' action preserves the date and that the 'fold' action uses the later date. The documentation was previously silent on this issue which left users in doubt.

localrepo: check HG_PENDING strictly Before this patch, checking HG_PENDING for changelog in localrepo.py might cause unintentional reading unrelated '00changelog.i.a' in, because HG_PENDING is checked by str.startswith(). An external hook spawned by inner repository in nested ones satisfies this condition. This patch uses txnutil.mayhavepending() to check HG_PENDING strictly. 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.

phases: check HG_PENDING strictly Before this patch, checking HG_PENDING in phases.py might cause unintentional reading unrelated 'phaseroots.pending' in, because it just examines existence of HG_PENDING environment variable. This patch uses txnutil.trypending() to check HG_PENDING strictly. 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.