tests/failfilemerge.py

typing: explicitly set the return type of `_InnerRevLog.raw_text()`

Somewhere between cd72a88c5599 and 2fd44b3dcc33, pytype changed the return type
from `Tuple[_T1, Any, bool]` to `Any`.  Both are wrong.  `mdiff.patches()` is an
alias for `mpatch.patches()`, which is selected via module policy (and breaks
the ability to infer the types).  However, `cext`, `cffi`, and `pure`
implementations all agree it returns bytes.

# extension to emulate interrupting filemerge._filemerge


from mercurial import (
    error,
    extensions,
    filemerge,
)


def failfilemerge(*args, **kwargs):
    raise error.Abort(b"^C")


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