[PATCH 1 of 4 V2] histedit: add a method to cleanup nodes safely

[Yuya Nishihara]

On Fri, 17 Mar 2017 20:17:48 -0700, Jun Wu wrote:
> # HG changeset patch
> # User Jun Wu <quark at fb.com>
> # Date 1489464645 25200
> #      Mon Mar 13 21:10:45 2017 -0700
> # Node ID 19a0f5164fcd28240327beffc3c90cdddfb17123
> # Parent  96929bd6e58d29bc3d44e1db7c1283f224bd1dc1
> # Available At https://bitbucket.org/quark-zju/hg-draft
> #              hg pull https://bitbucket.org/quark-zju/hg-draft -r 19a0f5164fcd
> histedit: add a method to cleanup nodes safely
> 
> The new method will decide between:
> 
>   - cleanupnode, which calls the unsafe repair.strip
>   - create obsmarkers
> 
> Ideally, nobody calls "cleanupnode" directly except for "safecleanupnode".
> 
> diff --git a/hgext/histedit.py b/hgext/histedit.py
> --- a/hgext/histedit.py
> +++ b/hgext/histedit.py
> @@ -1575,4 +1575,32 @@ def cleanupnode(ui, repo, name, nodes):
>              repair.strip(ui, repo, c)
>  
> +def safecleanupnode(ui, repo, name, nodes):
> +    """strip or obsolete nodes
> +
> +    nodes could be either a set or dict which maps to replacements.
> +    nodes could be unknown (outside the repo).
> +    """
> +    supportsmarkers = obsolete.isenabled(repo, obsolete.createmarkersopt)
> +    if supportsmarkers:
> +        if util.safehasattr(nodes, 'get'):
> +            # nodes is a dict-like mapping
> +            # use unfiltered repo for successors in case they are hidden
> +            urepo = repo.unfiltered()
> +            def getmarker(prec):
> +                succs = (urepo[n] for n in nodes.get(prec, ()))
> +                return (repo[prec], succs)

Still a generator?