contrib/python-hook-examples.py

hgweb: show as same parents as "hg parents -r REV FILE" in pages for file

Before this patch, "parents" in pages for file doesn't show as same
parents as "hg parents -r REV FILE", when the specified file is not
modified in the specified revision.

For example, it is assumed that revision A, B and D change file "f".

    changelog   (A) ---> (B) ---> (C) ---> (D)
    filelog "f" (x) ---> (y) ------------> (z)

"/file/D/f" invokes "webutil.parents()" with filectx(z) gotten from
changectx(D), and it returns changectx(B). This is as same result as
"hg parents -r D f".

In the other hand, "/file/C/f" invokes "webutil.parents()" with
filectx(y') gotten from changectx(C), and it returns changectx(A),
because filectx(y') is linked to changectx(B), and works like
filectx(y) in some cases.

In this case, revision B is hidden from users browsing file "f" in
revision C.

This patch shows as same parents as "hg parents -r REV FILE" in pages
for file, by making "webutil.parents()" return:

  - "linkrev()"-ed revision only, if:

    - specified context instance is "filectx" (because
      "webutil.parents()" is invoked with changectx, too), and

    - (1) the revision from which filectx is gotten and (2) the one to
      which filectx is linked are different from each other

  - revision gotten from "ctx.parents()", otherwise

'''
Examples of useful python hooks for Mercurial.
'''
from mercurial import patch, util

def diffstat(ui, repo, **kwargs):
    '''Example usage:

    [hooks]
    commit.diffstat = python:/path/to/this/file.py:diffstat
    changegroup.diffstat = python:/path/to/this/file.py:diffstat
    '''
    if kwargs.get('parent2'):
        return
    node = kwargs['node']
    first = repo[node].p1().node()
    if 'url' in kwargs:
        last = repo['tip'].node()
    else:
        last = node
    diff = patch.diff(repo, first, last)
    ui.write(patch.diffstat(util.iterlines(diff)))