Going through the PDF spec, it says that the trailer precedes the startxref. Which to me, says that the xref can appear anywhere in the document, but the trailer still appears before the startxref. This makes sense until you have to parse it, because you have to parse in reverse you can't take into account comments or strings. Lets get a little more wacky then.
trailer<< %\
/Size 4 %\
/Root 1 0 R %\
/Info 4 0 R %\
/Key (\
trailer<< %\
/Size 4 %\
/Root 2 0 R %\
/Info 3 0 R %\
>>%)
>>&)
% test test )
startxref
15
%%EOF
Which is a perfectly valid trailer. The first one is the real trailer, but the second one is in a "string". In this case, reverse parsing is going to fail to catch the comments. Looking for the string trailer is going to fail if its apart of a comment or string. I was wondering what the best way of finding out where the trailer starts is?
Update - This trailer seems to open in Acrobat Reader
%PDF-1.3
%âãÏÓ
xref
0 4
00000000 65535 f
00000110 00000 n
00000250 00000 n
00000315 00000 n
00000576 00000 n
1 0 obj <<
/Type /Catalog
/Pages 2 0 R
/OpenAction [ 3 0 R /XYZ null null null ]
/PageLabels << /Nums [0 << /S /D >> ] >>
>>
endobj
2 0 obj <<
/Type /Pages
/Kids [ 3 0 R ]
/Count 1
>>
endobj
3 0 obj <<
/Type /Page
/Parent 2 0 R
/Resources << >>
/MediaBox [ 0 0 612 792 ]
>>
endobj
4 0 obj <<
/Producer (Me)
/CreationDate (D:20110626000000Z)
>>
endobj
trailer<< %\
/Size 4 %\
/Root 1 0 R %\
/Info 4 0 R %\
/Key (\
trailer<< %\
/Size 4 %\
/Root 2 0 R %\
/Info 3 0 R %\
>>%)
>>%)
% test test )
startxref
15
%%EOF
As far as syntax goes, this conforms to spec. Somehow they seem to be able to know if they are in a comment, or a str