tests/failfilemerge.py

manifest: fix possible SEGV caused by uninitialized lazymanifest fields

Before, uninitialized self->pydata would be passed to lazymanifest_dealloc()
on OOM, and Py_DECREF(self->pydata) would crash if we were unlucky.

It's still wrong to do malloc() thingy in tp_init because __init__() may be
called more than once [1], but I don't want to go a step further in stable
branch.

 [1]: https://docs.python.org/2/c-api/typeobj.html#c.PyTypeObject.tp_new
 "The tp_new function should ... do only as much further initialization as
  is absolutely necessary. Initialization that can safely be ignored or
  repeated should be placed in the tp_init handler."

# extension to emulate interrupting filemerge._filemerge

from __future__ import absolute_import

from mercurial import (
    error,
    extensions,
    filemerge,
)

def failfilemerge(filemergefn,
                  premerge, repo, wctx, mynode, orig, fcd, fco, fca,
                  labels=None):
    raise error.Abort("^C")
    return filemergefn(premerge, repo, mynode, orig, fcd, fco, fca, labels)

def extsetup(ui):
    extensions.wrapfunction(filemerge, '_filemerge',
                            failfilemerge)