The Annoyance Filter.pdf - Fourmilab

114 MAIL FOLDER ANNOYANCE-FILTER §130
}
}
if (¬getline (∗is , s)) {
〈 Advance to next file if traversing directory 138 〉;
return false ;
}
}
}
nLines ++;
if (sloppyheaders ) { /∗ Spam seems to have begun to arrive with the required blank line
separating a mail message header and the first MIME separator. Since the “--” sequence
which precedes the sentinel (whatever it be) cannot appear in a legitimate header, we
check for it here and, if the header runs onto the sentinel, fake a blank line to properly
terminate the header. ∗/
if (inHeader ∧ multiPart ∧ (partBoundary ≠ "") ∧ (s.substr (0, 2) ≡ "−−") ∧ (s.substr (2,
partBoundary .length ( )) ≡ partBoundary )) {
if (Annotate (’d’)) {
ostringstream os ;
os ≪ "Header␣runs␣into␣−−" ≪ partBoundary ≪
"␣sentinel.␣␣Adding␣blank␣line␣to␣end␣header.";
reportParserDiagnostic(os );
}
assert(¬lookedAhead );
lookedAhead = true ;
lookAheadLine = s;
s = "";
}
}
if ((mdp ≡ Λ) ∧ (tlist ≠ Λ) ∧ (¬decoderEOF )) {
tlist ⃗ push back (s);
}
〈 Check for start of new message in folder 139 〉;
〈 Eliminate any trailing space from line 140 〉;
〈 Process message header lines 141 〉;
〈 Parse MIME part header 149 〉;
〈 Check for MIME part sentinel 151 〉;
〈 Decode multiple byte character set 152 〉;
return true ;