[PATCH] hgweb: follow renames and copies in file log (issue1576)

[Dirkjan Ochtman]

On Wed, Apr 6, 2011 at 16:34, Kevin Gessner <kevin at fogcreek.com> wrote:
> # HG changeset patch
> # User Kevin Gessner <kevin at fogcreek.com>
> # Date 1301949717 14400
> # Node ID 6df5de9f4dcbb71c4654a8d1c3181a96194d8579
> # Parent  086c9f203a53ee4b20a83d06c6e966ecc8a30cbf
> hgweb: follow renames and copies in file log (issue1576)
>
> When walking the requested filectx finds a rename or copy, recursively walk
> that filectx, adding as many changesets as needed, and following renames.
>
> Links to older revisions must include the path that the file had in that
> revision, so revnavgen and nodefunc must return path info from the correct
> filectx.
>
> diff --git a/mercurial/hgweb/webcommands.py b/mercurial/hgweb/webcommands.py
> --- a/mercurial/hgweb/webcommands.py
> +++ b/mercurial/hgweb/webcommands.py
> @@ -631,21 +631,34 @@
>     morevars = copy.copy(tmpl.defaults['sessionvars'])
>     morevars['revcount'] = revcount * 2
>
> -    count = fctx.filerev() + 1
> -    start = max(0, fctx.filerev() - revcount + 1) # first rev on this page
> +    def follow(fctx):
> +        l = []
> +        while fctx:
> +            l.insert(0, fctx)
> +            renamed = fctx.filectx(0).renamed()
> +            if renamed:
> +                fctx = web.repo.filectx(renamed[0], fileid=renamed[1])
> +            else:
> +                fctx = None
> +        return l
> +
> +    allfctx = follow(fctx)

Great that you're working on this! Some notes:

- This looks like it will repeatedly call list.insert(0, something),
which is potentially a big performance liability. Inserting at the
start of the list shifts all elements in the list to the right, so you
probably don't want to do it in this kind of loop.

- This also looks like you will always follow the first rename in the
history (calculated from the filelog's tip). Is that correct? I think
we would only want to follow the last one, i.e. short-circuit by going
to the first revision in this filelog and check if it was rename, move
on to that filelog, check its first revision, etc.

Cheers,

Dirkjan