tests/svn-safe-append.py

import-checker: use testparseutil.embedded() to centralize detection logic

This patch fixes issues of embedded() in import-checker.py below, too.

  - overlook (or mis-detect) the end of inline script in doctest style

  - overlook inline script in doctest style at the end of file
    (and ignore invalid un-closed heredoc at the end of file, too)

  - overlook code fragment in styles below
    - "python <<EOF" (heredoc should be "cat > file <<EOF" style)
    - "cat > foobar.py << ANYLIMIT" (limit mark should be "EOF")
    - "cat << EOF > foobar.py" (filename should be placed before limit mark)
    - "cat >> foobar.py << EOF" (appending is ignored)

#!/usr/bin/env python

from __future__ import absolute_import

__doc__ = """Same as `echo a >> b`, but ensures a changed mtime of b.
Without this svn will not detect workspace changes."""

import os
import stat
import sys

if sys.version_info[0] >= 3:
    text = os.fsencode(sys.argv[1])
    fname = os.fsencode(sys.argv[2])
else:
    text = sys.argv[1]
    fname = sys.argv[2]

f = open(fname, "ab")
try:
    before = os.fstat(f.fileno())[stat.ST_MTIME]
    f.write(text)
    f.write(b"\n")
finally:
    f.close()
inc = 1
now = os.stat(fname)[stat.ST_MTIME]
while now == before:
    t = now + inc
    inc += 1
    os.utime(fname, (t, t))
    now = os.stat(fname)[stat.ST_MTIME]