The Annoyance Filter.pdf - Fourmilab

124 MAIL FOLDER ANNOYANCE-FILTER §142
142. At the end of a MIME part, switch off the decoder and reset the part properties to void.
〈 Reset MIME decoder state 142 〉 ≡
mimeContentType = mimeContentTypeCharset = mimeContentTypeName =
mimeContentDispositionFilename = mimeContentTypeBoundary =
mimeContentTransferEncoding = "";
mdp = Λ;
mbi = Λ;
asp = Λ;
byteStream = false ;
This code is used in sections 129, 130, 139, and 162.
143. Statements in the message header section may be continued onto multiple lines. Continuations
are denoted by white space in the first column of successive continuations. To simplify header parsing,
we look ahead and concatenate all continuations into one single header statement. The twiddling with
lal in the following code is to ensure the integrity of transcripts. We delete trailing space from the look
ahead line before concatenating it, but if we in fact looked ahead to a line which is not a continuation,
we want to eventually save it in the transcript as it originally arrived, complete with trailing space, so
we replace it with the original line before deleting the trailing space.
〈 Check for continuation of mail header lines 143 〉 ≡
〈 Check for lines with our sentinel already present in the header 144 〉;
while ((inHeader ∨ inPartHeader ) ∧ getline (∗is , lookAheadLine ) ≠ Λ) {
string lal = lookAheadLine ;
while ((lookAheadLine .length ( ) > 0) ∧ (isISOspace (lookAheadLine [lookAheadLine .length ( ) − 1])))
{
lookAheadLine .erase (lookAheadLine .length ( ) − 1);
}
if ((lookAheadLine .length ( ) > 0) ∧ isISOspace (lookAheadLine [0])) {
string ::size type p = 1;
while (isISOspace (lookAheadLine [p])) {
p++;
}
s += lookAheadLine .substr (p);
if ((tlist ≠ Λ) ∧ (¬isSpoofedHeader )) {
tlist ⃗ push back (lal );
}
continue;
}
lookedAhead = true ;
lookAheadLine = lal ;
break;
}
if (isSpoofedHeader ) {
ostringstream os ;
}
os ≪ "Spoofed␣header␣rejected:␣" ≪ s;
reportParserDiagnostic(os .str ( ));
continue;
This code is cited in section 256.
This code is used in section 141.