diff options
Diffstat (limited to 'Lib/email/generator.py')
| -rw-r--r-- | Lib/email/generator.py | 66 |
1 files changed, 40 insertions, 26 deletions
diff --git a/Lib/email/generator.py b/Lib/email/generator.py index f0e7a95..d8b8fa9 100644 --- a/Lib/email/generator.py +++ b/Lib/email/generator.py @@ -13,8 +13,10 @@ import random import warnings from io import StringIO, BytesIO +from email import policy from email.header import Header from email.message import _has_surrogates +import email.charset as _charset UNDERSCORE = '_' NL = '\n' # XXX: no longer used by the code below. @@ -33,7 +35,8 @@ class Generator: # Public interface # - def __init__(self, outfp, mangle_from_=True, maxheaderlen=78): + def __init__(self, outfp, mangle_from_=True, maxheaderlen=None, *, + policy=policy.default): """Create the generator for message flattening. outfp is the output file-like object for writing the message to. It @@ -49,16 +52,23 @@ class Generator: defined in the Header class. Set maxheaderlen to zero to disable header wrapping. The default is 78, as recommended (but not required) by RFC 2822. + + The policy keyword specifies a policy object that controls a number of + aspects of the generator's operation. The default policy maintains + backward compatibility. + """ self._fp = outfp self._mangle_from_ = mangle_from_ - self._maxheaderlen = maxheaderlen + self._maxheaderlen = (maxheaderlen if maxheaderlen is not None else + policy.max_line_length) + self.policy = policy def write(self, s): # Just delegate to the file object self._fp.write(s) - def flatten(self, msg, unixfrom=False, linesep='\n'): + def flatten(self, msg, unixfrom=False, linesep=None): r"""Print the message object tree rooted at msg to the output file specified when the Generator instance was created. @@ -70,17 +80,15 @@ class Generator: Note that for subobjects, no From_ line is printed. linesep specifies the characters used to indicate a new line in - the output. The default value is the most useful for typical - Python applications, but it can be set to \r\n to produce RFC-compliant - line separators when needed. + the output. The default value is determined by the policy. """ # We use the _XXX constants for operating on data that comes directly # from the msg, and _encoded_XXX constants for operating on data that # has already been converted (to bytes in the BytesGenerator) and # inserted into a temporary buffer. - self._NL = linesep - self._encoded_NL = self._encode(linesep) + self._NL = linesep if linesep is not None else self.policy.linesep + self._encoded_NL = self._encode(self._NL) self._EMPTY = '' self._encoded_EMTPY = self._encode('') if unixfrom: @@ -297,10 +305,12 @@ class Generator: # message/rfc822. Such messages are generated by, for example, # Groupwise when forwarding unadorned messages. (Issue 7970.) So # in that case we just emit the string body. - payload = msg.get_payload() + payload = msg._payload if isinstance(payload, list): g.flatten(msg.get_payload(0), unixfrom=False, linesep=self._NL) payload = s.getvalue() + else: + payload = self._encode(payload) self._fp.write(payload) # This used to be a module level function; we use a classmethod for this @@ -336,7 +346,10 @@ class BytesGenerator(Generator): Functionally identical to the base Generator except that the output is bytes and not string. When surrogates were used in the input to encode - bytes, these are decoded back to bytes for output. + bytes, these are decoded back to bytes for output. If the policy has + must_be_7bit set true, then the message is transformed such that the + non-ASCII bytes are properly content transfer encoded, using the + charset unknown-8bit. The outfp object must accept bytes in its write method. """ @@ -359,21 +372,22 @@ class BytesGenerator(Generator): # strings with 8bit bytes. for h, v in msg._headers: self.write('%s: ' % h) - if isinstance(v, Header): - self.write(v.encode(maxlinelen=self._maxheaderlen)+NL) - elif _has_surrogates(v): - # If we have raw 8bit data in a byte string, we have no idea - # what the encoding is. There is no safe way to split this - # string. If it's ascii-subset, then we could do a normal - # ascii split, but if it's multibyte then we could break the - # string. There's no way to know so the least harm seems to - # be to not split the string and risk it being too long. - self.write(v+NL) - else: - # Header's got lots of smarts and this string is safe... - header = Header(v, maxlinelen=self._maxheaderlen, - header_name=h) - self.write(header.encode(linesep=self._NL)+self._NL) + if isinstance(v, str): + if _has_surrogates(v): + if not self.policy.must_be_7bit: + # If we have raw 8bit data in a byte string, we have no idea + # what the encoding is. There is no safe way to split this + # string. If it's ascii-subset, then we could do a normal + # ascii split, but if it's multibyte then we could break the + # string. There's no way to know so the least harm seems to + # be to not split the string and risk it being too long. + self.write(v+NL) + continue + h = Header(v, charset=_charset.UNKNOWN8BIT, header_name=h) + else: + h = Header(v, header_name=h) + self.write(h.encode(linesep=self._NL, + maxlinelen=self._maxheaderlen)+self._NL) # A blank line always separates headers from body self.write(self._NL) @@ -382,7 +396,7 @@ class BytesGenerator(Generator): # just write it back out. if msg._payload is None: return - if _has_surrogates(msg._payload): + if _has_surrogates(msg._payload) and not self.policy.must_be_7bit: self.write(msg._payload) else: super(BytesGenerator,self)._handle_text(msg) |