Bruno,

1T3XT info wrote:
> 
> If I look at http://1t3xt.be/?X0000f8
> And I look at the xref table, I see:
> 
> xref
> 0 17
> 0000000000 65535 f
> 0000000000 65536 n
> 0000000233 00000 n
> 0000000015 00000 n
> 0000000145 00000 n
> 0000001271 00000 n
> 0000000000 65536 n
> 0000000593 00000 n
> 0000000385 00000 n
> 0000000479 00000 n
> 0000000000 65536 n
> 0000001101 00000 n
> 0000000741 00000 n
> 0000000884 00000 n
> 0000000973 00000 n
> 0000001335 00000 n
> 0000001381 00000 n
> 
> Loooking at the error message, I wonder if Ghostscript is complaining
> about the "0000000000 65536 n" entries.
> 

It may very well be complaining about them, the PDF spec states on
cross-reference tables:

"Except for object number 0, all objects in the cross-reference table shall
initially have generation numbers of 0. When an indirect object is deleted,
its cross-reference entry shall be marked free and it shall be added to the
linked list of free entries. The entry’s generation number shall be
incremented by 1 to indicate the generation number to be used the next time
an object with that object number is created. Thus, each time the entry is
reused, it is given a new generation number. The maximum generation number
is 65,535; when a crossreference entry reaches this value, it shall never be
reused."

Especially the "The maximum generation number is 65,535" part is
interesting.

Unfortunately this limit on generation numbers (and the rule on starting
with generation 0 and incrementing it by 1 on reuse until that limit is
reached) is only mentioned in the explanation of the cross reference entries
for free objects while for in-use objects it simply says "The generation
number shall be a 5-digit number, also padded with leading zeros if
necessary."

OTOH, there also is "The cross-reference entry for a free object has
essentially the same format, except that the keyword shall be f instead of n
and the interpretation of the first item is different"; this might be
considered to imply that the limits and rules for the second item (i.e. the
generation number) shall be followed for both free and in-use objects
regardless of the context they appear in.

BTW, is there a special reason for all these free objects to appear in the
cross-reference table as in-use objects pointing to the invalid offset 0?

Regards,   Michael.
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