tests/hgweberror.py

merge: respect parents order when using `graft` on a merge

The previous code did not record the index of the replaced parent. It was always
using the "graft" destination as `p1`. This could switch parents order in some
situation (eg: some of the evolve evolving merge case). Recording and using the
information fixes the issue in evolve.

We are not aware of core commands calling graft in that fashion, so we could not
build a simple test case for it using core commands.

# A dummy extension that installs an hgweb command that throws an Exception.

from __future__ import absolute_import

from mercurial.hgweb import (
    webcommands,
)

def raiseerror(web):
    '''Dummy web command that raises an uncaught Exception.'''

    # Simulate an error after partial response.
    if b'partialresponse' in web.req.qsparams:
        web.res.status = b'200 Script output follows'
        web.res.headers[b'Content-Type'] = b'text/plain'
        web.res.setbodywillwrite()
        list(web.res.sendresponse())
        web.res.getbodyfile().write(b'partial content\n')

    raise AttributeError('I am an uncaught error!')

def extsetup(ui):
    setattr(webcommands, 'raiseerror', raiseerror)
    webcommands.__all__.append(b'raiseerror')