contrib/python-hook-examples.py

tests: omit -p for external diff via extdiff extension for portability

Before this patch, some tests using external "diff" command via
extdiff extension fail on Solaris, because "-p" (show which C function
each change is in) option isn't supported by system standard "diff" on
Solaris, even though extdiff passes it to external "diff" by default.

Fortunately, this non-portable option isn't important for (current, at
least) tests using external "diff" command via extdiff extension.

This patch omits "-p" for external "diff" command via extdiff
extension for portability of tests, and adds check-code.py a rule to
detect invocation of "diff" with "-p".

Newly added check-code.py rule examines only lines generated by
external "diff" with "-r", because strict examination might
misidentify "hg diff -p" or other complicated lines consisting of
"diff" string as wrong one.

This patch is a part of making tests using external "diff" portable,
and tests below aren't yet portable even after this patch.

  test-graft.t
  test-largefiles-update.t
  test-subrepo-deep-nested-change.t

'''
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)))