Extraction walked the name tree again with a fresh key budget, so keys
the listing had left out could fill it and a listed embedded file came
back as not found. The lookup compares each key with the one wanted and
keeps none, so it needs no budget; a key object or /Names array that
several places reference is converted once.
A kept web address or attachment text spent only its converted length,
so a long raw value that trimmed short was converted in full for every
entry sharing it. A kept conversion now spends the longer of its raw
and converted lengths.
The embedded-files name tree copied every key, and an attachment
without a file name copied its key again as the name, so many entries
sharing one long key string multiplied it. Keys, and a key kept again
as the name, now spend the 16 MiB link and attachment text budget; an
embedded file whose key does not fit is not listed.
An annotation attachment's /Contents was read and charged to the text
budget before the file specification's /UF or /F, which then named the
attachment, so the discarded text could leave a later web address
unlisted. /Contents is now read only when neither name is there.
A web address or attachment text that converted to more than the budget
left spent nothing, so every link or attachment sharing it converted it
again. A conversion that comes out too long now spends the raw length,
and so does attachment text that trims to nothing.
The link and attachment listings copied a link's web address and an
attachment's name and description for every annotation or name-tree
entry, so many entries sharing one long string multiplied it in
memory. Together they keep at most 16 MiB of that text, and a string
past what is left is not converted. A link past it lists as a URI
action without its address, an attachment under its generic name
without a description.
The annotation listing skipped a repeated /Annots entry by its raw
reference, so an indirect object holding only a reference to a link
listed that link a second time. Entries and page arrays are now told
apart by the object their reference chain ends at. The lopdf reader
reported the first object of a chain, because lopdf's get_object
already follows it; it now reports the last, as the lazy reader does.
A section naming an /XRefStm that a newer section had already read
skipped the stream entirely, so an entry in its own table that
disagreed with the stream was no longer recorded in xref_oddities.
Signature validation reads those records to refuse an appended section
another reader could follow. The reader keeps each hybrid stream's
entries (up to MAX_XREF_OBJECTS in all) and compares every later
naming section's table with them, without decoding the stream again.
#4114 moves the bodies of Stream::decoded_within and decoded_strict into
decoded_within_typed and decoded_strict_within_typed, which return
FilterError so DecodeBudget can tell a spent limit from corrupt data.
This branch checks /Filter with readable_filters there. Kept #4114's
typed functions and made readable_filters return
FilterError::Unsupported, so a /Filter that is not a name fails both
typed decodes without charging the budget; decoded_first_filter_strict
maps it to CosError as before.
The text layout cut each embedded value to the bytes its block had left, but
the resolver cloned the whole value first. With a byte or two left and a
value starting with a multibyte character, every later run cloned the full
value and kept none of it. The resolver is given the bytes left and returns
only a prefix that fits.
set_value charged the snapshot's copy, changed the field, then charged the
effect's copy in push. When only the first fit, the effect was dropped while
later reads in the script saw the new value. Both copies are charged at once
before the field changes.
A positioned root draws its children instead of flowing them, so nested
repeating subforms under it multiplied their instances without spending
the measurement budget that flowed instances spend. Drawing a subform
instance spends it too.
The evidence caps counted repeated references to one stream, so a /DSS
array could list one benign stream 1024 times ahead of a revoking CRL,
and the check never reached it. Repeats are skipped before the entry
cap counts anything, and when a cap still stops an array being read in
full without a revocation found, the signature's status is unknown
rather than valid, with the reason in its details.
Reaching the 64 MiB comment budget ended the whole annotation scan, so
links and file attachments listed after it were missing, and a later
JavaScript link left the document unmarked. Past the budget, comments
are no longer built, and the scan goes on for links and attachments.
An address of invalid UTF-8 grows up to three times when converted, so
the listing's 16 MiB cap counted fewer bytes than it kept. The cap now
counts the converted text; the raw length is still checked first, so an
address already over the cap is never converted.
Redaction reads page content and form XObjects strictly (upstream) and
within one page's decode budget (this branch): both now go through
DecodeBudget::decode_strict.
Filtered inline image data has no length, so its end is an EI chosen
among candidates, and the content parser chose by a different rule
than the renderer's tokenizer (hayro-syntax): the renderer also takes an
EI with no whitespace before it, and checks a candidate by reading what
follows as operators. With image data such as "7FEI 1 0 0 1 200 0 cm",
the renderer ran a cm that redaction read as image data, so text was
drawn 200 pt from where removal and its verify pass looked.
The parser now takes each inline image's end from the renderer's
tokenizer (already in the tree through pdfcraft-cos), so both read the
same operators after the image; a test runs both on the same fixtures.
Only where that tokenizer reads no image (no EI it accepts, or
parameters it can't read) does the parser fall back to its own rules,
counting the image in Parsed::ambiguous_images, and applying redactions
refuses such a page as unreadable.
Structure cleanup cleared alternate text, actual text and expansions
only on the element that directly owned changed marked content, and an
element that lost an annotation reference kept its descriptions unless
it lost every kid. An ancestor's /ActualText covering a redacted span,
or a link element's /Alt repeating the address of a removed link, stayed
in the saved file. Elements that lose an annotation now always lose
their descriptions, and every ancestor of an affected element (found
through both /P and the tree's /K, which may disagree) loses its own.
An element written in place above one with a description to clear
refuses the operation, as other in-place cases already do.
Finding which marked content a redaction changed copied every operator
into the buffer of each MCID enclosing it, so content nested n deep was
held n times: a modest stream of nested BDCs could exhaust memory.
Each operator inside marked content is now serialized once, and each
MCID keeps the ranges its sequences span. The bytes compared are capped;
MCIDs past the cap count as changed, so their descriptions are cleared
rather than kept.
Eric Kaden