--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/planemo/lib/python3.7/site-packages/future/backports/email/utils.py	Fri Jul 31 00:18:57 2020 -0400
@@ -0,0 +1,400 @@
+# Copyright (C) 2001-2010 Python Software Foundation
+# Author: Barry Warsaw
+# Contact: email-sig@python.org
+
+"""Miscellaneous utilities."""
+
+from __future__ import unicode_literals
+from __future__ import division
+from __future__ import absolute_import
+from future import utils
+from future.builtins import bytes, int, str
+
+__all__ = [
+    'collapse_rfc2231_value',
+    'decode_params',
+    'decode_rfc2231',
+    'encode_rfc2231',
+    'formataddr',
+    'formatdate',
+    'format_datetime',
+    'getaddresses',
+    'make_msgid',
+    'mktime_tz',
+    'parseaddr',
+    'parsedate',
+    'parsedate_tz',
+    'parsedate_to_datetime',
+    'unquote',
+    ]
+
+import os
+import re
+if utils.PY2:
+    re.ASCII = 0
+import time
+import base64
+import random
+import socket
+from future.backports import datetime
+from future.backports.urllib.parse import quote as url_quote, unquote as url_unquote
+import warnings
+from io import StringIO
+
+from future.backports.email._parseaddr import quote
+from future.backports.email._parseaddr import AddressList as _AddressList
+from future.backports.email._parseaddr import mktime_tz
+
+from future.backports.email._parseaddr import parsedate, parsedate_tz, _parsedate_tz
+
+from quopri import decodestring as _qdecode
+
+# Intrapackage imports
+from future.backports.email.encoders import _bencode, _qencode
+from future.backports.email.charset import Charset
+
+COMMASPACE = ', '
+EMPTYSTRING = ''
+UEMPTYSTRING = ''
+CRLF = '\r\n'
+TICK = "'"
+
+specialsre = re.compile(r'[][\\()<>@,:;".]')
+escapesre = re.compile(r'[\\"]')
+
+# How to figure out if we are processing strings that come from a byte
+# source with undecodable characters.
+_has_surrogates = re.compile(
+    '([^\ud800-\udbff]|\A)[\udc00-\udfff]([^\udc00-\udfff]|\Z)').search
+
+# How to deal with a string containing bytes before handing it to the
+# application through the 'normal' interface.
+def _sanitize(string):
+    # Turn any escaped bytes into unicode 'unknown' char.
+    original_bytes = string.encode('ascii', 'surrogateescape')
+    return original_bytes.decode('ascii', 'replace')
+
+
+# Helpers
+
+def formataddr(pair, charset='utf-8'):
+    """The inverse of parseaddr(), this takes a 2-tuple of the form
+    (realname, email_address) and returns the string value suitable
+    for an RFC 2822 From, To or Cc header.
+
+    If the first element of pair is false, then the second element is
+    returned unmodified.
+
+    Optional charset if given is the character set that is used to encode
+    realname in case realname is not ASCII safe.  Can be an instance of str or
+    a Charset-like object which has a header_encode method.  Default is
+    'utf-8'.
+    """
+    name, address = pair
+    # The address MUST (per RFC) be ascii, so raise an UnicodeError if it isn't.
+    address.encode('ascii')
+    if name:
+        try:
+            name.encode('ascii')
+        except UnicodeEncodeError:
+            if isinstance(charset, str):
+                charset = Charset(charset)
+            encoded_name = charset.header_encode(name)
+            return "%s <%s>" % (encoded_name, address)
+        else:
+            quotes = ''
+            if specialsre.search(name):
+                quotes = '"'
+            name = escapesre.sub(r'\\\g<0>', name)
+            return '%s%s%s <%s>' % (quotes, name, quotes, address)
+    return address
+
+
+
+def getaddresses(fieldvalues):
+    """Return a list of (REALNAME, EMAIL) for each fieldvalue."""
+    all = COMMASPACE.join(fieldvalues)
+    a = _AddressList(all)
+    return a.addresslist
+
+
+
+ecre = re.compile(r'''
+  =\?                   # literal =?
+  (?P<charset>[^?]*?)   # non-greedy up to the next ? is the charset
+  \?                    # literal ?
+  (?P<encoding>[qb])    # either a "q" or a "b", case insensitive
+  \?                    # literal ?
+  (?P<atom>.*?)         # non-greedy up to the next ?= is the atom
+  \?=                   # literal ?=
+  ''', re.VERBOSE | re.IGNORECASE)
+
+
+def _format_timetuple_and_zone(timetuple, zone):
+    return '%s, %02d %s %04d %02d:%02d:%02d %s' % (
+        ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][timetuple[6]],
+        timetuple[2],
+        ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun',
+         'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][timetuple[1] - 1],
+        timetuple[0], timetuple[3], timetuple[4], timetuple[5],
+        zone)
+
+def formatdate(timeval=None, localtime=False, usegmt=False):
+    """Returns a date string as specified by RFC 2822, e.g.:
+
+    Fri, 09 Nov 2001 01:08:47 -0000
+
+    Optional timeval if given is a floating point time value as accepted by
+    gmtime() and localtime(), otherwise the current time is used.
+
+    Optional localtime is a flag that when True, interprets timeval, and
+    returns a date relative to the local timezone instead of UTC, properly
+    taking daylight savings time into account.
+
+    Optional argument usegmt means that the timezone is written out as
+    an ascii string, not numeric one (so "GMT" instead of "+0000"). This
+    is needed for HTTP, and is only used when localtime==False.
+    """
+    # Note: we cannot use strftime() because that honors the locale and RFC
+    # 2822 requires that day and month names be the English abbreviations.
+    if timeval is None:
+        timeval = time.time()
+    if localtime:
+        now = time.localtime(timeval)
+        # Calculate timezone offset, based on whether the local zone has
+        # daylight savings time, and whether DST is in effect.
+        if time.daylight and now[-1]:
+            offset = time.altzone
+        else:
+            offset = time.timezone
+        hours, minutes = divmod(abs(offset), 3600)
+        # Remember offset is in seconds west of UTC, but the timezone is in
+        # minutes east of UTC, so the signs differ.
+        if offset > 0:
+            sign = '-'
+        else:
+            sign = '+'
+        zone = '%s%02d%02d' % (sign, hours, minutes // 60)
+    else:
+        now = time.gmtime(timeval)
+        # Timezone offset is always -0000
+        if usegmt:
+            zone = 'GMT'
+        else:
+            zone = '-0000'
+    return _format_timetuple_and_zone(now, zone)
+
+def format_datetime(dt, usegmt=False):
+    """Turn a datetime into a date string as specified in RFC 2822.
+
+    If usegmt is True, dt must be an aware datetime with an offset of zero.  In
+    this case 'GMT' will be rendered instead of the normal +0000 required by
+    RFC2822.  This is to support HTTP headers involving date stamps.
+    """
+    now = dt.timetuple()
+    if usegmt:
+        if dt.tzinfo is None or dt.tzinfo != datetime.timezone.utc:
+            raise ValueError("usegmt option requires a UTC datetime")
+        zone = 'GMT'
+    elif dt.tzinfo is None:
+        zone = '-0000'
+    else:
+        zone = dt.strftime("%z")
+    return _format_timetuple_and_zone(now, zone)
+
+
+def make_msgid(idstring=None, domain=None):
+    """Returns a string suitable for RFC 2822 compliant Message-ID, e.g:
+
+    <20020201195627.33539.96671@nightshade.la.mastaler.com>
+
+    Optional idstring if given is a string used to strengthen the
+    uniqueness of the message id.  Optional domain if given provides the
+    portion of the message id after the '@'.  It defaults to the locally
+    defined hostname.
+    """
+    timeval = time.time()
+    utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval))
+    pid = os.getpid()
+    randint = random.randrange(100000)
+    if idstring is None:
+        idstring = ''
+    else:
+        idstring = '.' + idstring
+    if domain is None:
+        domain = socket.getfqdn()
+    msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, domain)
+    return msgid
+
+
+def parsedate_to_datetime(data):
+    _3to2list = list(_parsedate_tz(data))
+    dtuple, tz, = [_3to2list[:-1]] + _3to2list[-1:]
+    if tz is None:
+        return datetime.datetime(*dtuple[:6])
+    return datetime.datetime(*dtuple[:6],
+            tzinfo=datetime.timezone(datetime.timedelta(seconds=tz)))
+
+
+def parseaddr(addr):
+    addrs = _AddressList(addr).addresslist
+    if not addrs:
+        return '', ''
+    return addrs[0]
+
+
+# rfc822.unquote() doesn't properly de-backslash-ify in Python pre-2.3.
+def unquote(str):
+    """Remove quotes from a string."""
+    if len(str) > 1:
+        if str.startswith('"') and str.endswith('"'):
+            return str[1:-1].replace('\\\\', '\\').replace('\\"', '"')
+        if str.startswith('<') and str.endswith('>'):
+            return str[1:-1]
+    return str
+
+
+
+# RFC2231-related functions - parameter encoding and decoding
+def decode_rfc2231(s):
+    """Decode string according to RFC 2231"""
+    parts = s.split(TICK, 2)
+    if len(parts) <= 2:
+        return None, None, s
+    return parts
+
+
+def encode_rfc2231(s, charset=None, language=None):
+    """Encode string according to RFC 2231.
+
+    If neither charset nor language is given, then s is returned as-is.  If
+    charset is given but not language, the string is encoded using the empty
+    string for language.
+    """
+    s = url_quote(s, safe='', encoding=charset or 'ascii')
+    if charset is None and language is None:
+        return s
+    if language is None:
+        language = ''
+    return "%s'%s'%s" % (charset, language, s)
+
+
+rfc2231_continuation = re.compile(r'^(?P<name>\w+)\*((?P<num>[0-9]+)\*?)?$',
+    re.ASCII)
+
+def decode_params(params):
+    """Decode parameters list according to RFC 2231.
+
+    params is a sequence of 2-tuples containing (param name, string value).
+    """
+    # Copy params so we don't mess with the original
+    params = params[:]
+    new_params = []
+    # Map parameter's name to a list of continuations.  The values are a
+    # 3-tuple of the continuation number, the string value, and a flag
+    # specifying whether a particular segment is %-encoded.
+    rfc2231_params = {}
+    name, value = params.pop(0)
+    new_params.append((name, value))
+    while params:
+        name, value = params.pop(0)
+        if name.endswith('*'):
+            encoded = True
+        else:
+            encoded = False
+        value = unquote(value)
+        mo = rfc2231_continuation.match(name)
+        if mo:
+            name, num = mo.group('name', 'num')
+            if num is not None:
+                num = int(num)
+            rfc2231_params.setdefault(name, []).append((num, value, encoded))
+        else:
+            new_params.append((name, '"%s"' % quote(value)))
+    if rfc2231_params:
+        for name, continuations in rfc2231_params.items():
+            value = []
+            extended = False
+            # Sort by number
+            continuations.sort()
+            # And now append all values in numerical order, converting
+            # %-encodings for the encoded segments.  If any of the
+            # continuation names ends in a *, then the entire string, after
+            # decoding segments and concatenating, must have the charset and
+            # language specifiers at the beginning of the string.
+            for num, s, encoded in continuations:
+                if encoded:
+                    # Decode as "latin-1", so the characters in s directly
+                    # represent the percent-encoded octet values.
+                    # collapse_rfc2231_value treats this as an octet sequence.
+                    s = url_unquote(s, encoding="latin-1")
+                    extended = True
+                value.append(s)
+            value = quote(EMPTYSTRING.join(value))
+            if extended:
+                charset, language, value = decode_rfc2231(value)
+                new_params.append((name, (charset, language, '"%s"' % value)))
+            else:
+                new_params.append((name, '"%s"' % value))
+    return new_params
+
+def collapse_rfc2231_value(value, errors='replace',
+                           fallback_charset='us-ascii'):
+    if not isinstance(value, tuple) or len(value) != 3:
+        return unquote(value)
+    # While value comes to us as a unicode string, we need it to be a bytes
+    # object.  We do not want bytes() normal utf-8 decoder, we want a straight
+    # interpretation of the string as character bytes.
+    charset, language, text = value
+    rawbytes = bytes(text, 'raw-unicode-escape')
+    try:
+        return str(rawbytes, charset, errors)
+    except LookupError:
+        # charset is not a known codec.
+        return unquote(text)
+
+
+#
+# datetime doesn't provide a localtime function yet, so provide one.  Code
+# adapted from the patch in issue 9527.  This may not be perfect, but it is
+# better than not having it.
+#
+
+def localtime(dt=None, isdst=-1):
+    """Return local time as an aware datetime object.
+
+    If called without arguments, return current time.  Otherwise *dt*
+    argument should be a datetime instance, and it is converted to the
+    local time zone according to the system time zone database.  If *dt* is
+    naive (that is, dt.tzinfo is None), it is assumed to be in local time.
+    In this case, a positive or zero value for *isdst* causes localtime to
+    presume initially that summer time (for example, Daylight Saving Time)
+    is or is not (respectively) in effect for the specified time.  A
+    negative value for *isdst* causes the localtime() function to attempt
+    to divine whether summer time is in effect for the specified time.
+
+    """
+    if dt is None:
+        return datetime.datetime.now(datetime.timezone.utc).astimezone()
+    if dt.tzinfo is not None:
+        return dt.astimezone()
+    # We have a naive datetime.  Convert to a (localtime) timetuple and pass to
+    # system mktime together with the isdst hint.  System mktime will return
+    # seconds since epoch.
+    tm = dt.timetuple()[:-1] + (isdst,)
+    seconds = time.mktime(tm)
+    localtm = time.localtime(seconds)
+    try:
+        delta = datetime.timedelta(seconds=localtm.tm_gmtoff)
+        tz = datetime.timezone(delta, localtm.tm_zone)
+    except AttributeError:
+        # Compute UTC offset and compare with the value implied by tm_isdst.
+        # If the values match, use the zone name implied by tm_isdst.
+        delta = dt - datetime.datetime(*time.gmtime(seconds)[:6])
+        dst = time.daylight and localtm.tm_isdst > 0
+        gmtoff = -(time.altzone if dst else time.timezone)
+        if delta == datetime.timedelta(seconds=gmtoff):
+            tz = datetime.timezone(delta, time.tzname[dst])
+        else:
+            tz = datetime.timezone(delta)
+    return dt.replace(tzinfo=tz)