A cubic whose second control point is its end point (as the `y` operator builds,
ISO 32000-2 8.5.2.1 Table 58) has a zero derivative at its end. kurbo 0.13.1's
offset curve looks for cusps with a root search on the curvature, which grows
without bound towards that end; at some widths the search stops on the end point
and normalising the zero tangent there gives NaN. vello_common's fill drops any
outline with NaN, so the whole stroke vanished (a two-curve `y` path drew nothing
at 16, 32 and 63 pt; a PDFBox tracker file lost its 32 pt "XX" outline).
The NaN fallback that #4913 added to `flatten::stroke` now also moves such a
control point the stroke tolerance towards the previous control point before
stroking again (the curve moves by at most 4/9 of the tolerance). Outlines that
come back finite take the old path unchanged. The vendor ledger row also gets
back #4913's entry, which a merge had dropped.
Claude-Session: https://claude.ai/code/session_01Pq7HyCHD1R3rywQBPCHXZA
Co-authored-by: mtlcl410 <chuanlin@niar.org.tw>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
* M2: a form XObject that draws itself is drawn once (hayro-interpret patch 89)
A form whose content names itself, directly or through another form, a
pattern or a glyph, drew itself again at every level until the page's
nested-paint budget (50,000) ran out. PDFBOX-5782's poppler-748 page 2,
whose form names a /Pages dictionary as /X0 and so finds itself in the
page's resources, took 38 s.
hayro-interpret now keeps the forms being drawn on the context and skips
a form already on it, reporting ContentTruncated (ISO 32000-2 §8.10.1: a
form is a self-contained description). The lenient fallback from a form's
own resources to the page's stays: MuPDF, Poppler and PDFium all draw a
name from the page's resources when the form's /Resources has no
XObject subdictionary (MuPDF and Poppler also when it has an empty one).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
* fix(render): a form that reaches itself through a pattern or a glyph is drawn once (hayro-interpret patch 89)
The forms being drawn are now kept per page and thread rather than per
context, so the tiling patterns, Type 3 glyphs, soft masks and groups
painted inside a form, which hayro interprets in contexts of their own,
see that the form is being drawn and skip it inside themselves. A form
drawn again after it has finished draws as before.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyCHD1R3rywQBPCHXZA
* chore: re-run CI after the Fill & Sign save comparison failed on the clock (#6066)
`fill_sign_enter_adds_lines_outside_click_commits_and_escape_cancels`
compares two saves whose /ModDate fell in different seconds; it passes
locally on this commit. No change.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyCHD1R3rywQBPCHXZA
---------
Co-authored-by: mtlcl410 <chuanlin@niar.org.tw>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
TIFF predictor 2 (ISO 32000-2 §7.4.4.4, Table 10) went through the
bit-level BitChunks/BitWriter path for every bit depth, re-reading the
previous output pixel through a new BitReader per pixel. Whole-byte
samples (8 and 16 bits per component) are now undone on byte slices,
each sample added to the same component of the pixel to its left,
wrapping at its width; 1-, 2- and 4-bit samples keep the bit-level path.
The output is byte-identical, including the dropped partial last row.
A page of 45 full-page 8-bit grey images so predicted (PDFBOX-1350)
renders in about 4 s instead of 23 s with the same pixels.
Vendored hayro-syntax patch 42.
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
Co-authored-by: mtlcl410 <chuanlin@niar.org.tw>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
* M5: a comment whose colour is written [r g b null] is drawn, as CMYK with the null read as 0 (view.render-annotation-appearances)
ISO 32000-2 Table 166 /C (and /IC, Tables 178, 180, 181; /MK /BC and /BG,
Table 192) is an array of 0, 1, 3 or 4 numbers whose length picks the
colour space. A four-entry array with a non-number in it, such as
[1 0 0 null] (PDFBOX-2699), made the /C parser give up, so a shape
without an appearance stream was not drawn at all. PDFium, MuPDF and
Poppler all read such an array as CMYK with the non-number as 0.
- annot: a four-entry /C or /IC reads non-numbers as 0; other lengths
still need every entry to be a number.
- annot: the properties' fill uses the same parser (it read
[r g b null] as RGB before), and /C no longer drops a non-number
to make three numbers.
- forms: /MK /BC and /BG read a four-entry array the same way instead
of dropping the non-number and drawing RGB.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
* M5: comment properties report the stroke colour as drawn; a reference among four colour entries is not read as 0 (view.render-annotation-appearances)
props() reads a non-FreeText /C through the appearance parser, so a
[1 0 0 null] stroke reports CMYK cyan as drawn, and grey and CMYK
strokes report their converted colour. A reference among the four
entries of a /C array (ISO 32000-2 7.3.10) is left unreadable instead
of standing in as 0, so /C [1 0 0 6 0 R] is never drawn cyan.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
* M5: re-run CI (fill_sign Escape test depends on the clock's second, passes locally)
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
* M5: the comment list reports a comment's colour as drawn (view.render-annotation-appearances)
summaries() accepted only a three-entry /C, so a Square with /C [1 0 0 null],
drawn cyan and reported cyan by props(), had no colour in the comment list;
grey and CMYK colours were dropped the same way. Non-FreeText comments now
read /C through drawn_color (the array itself followed when it is given by
reference), keeping the three-number fallback and the FreeText /DA handling.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
* M5: the render inspector lists a comment's colour as drawn (view.render-annotation-appearances)
The inspector accepted only a three-entry /C, with a referenced entry read
as 0, so a /C [1 0 0 null], a grey or a CMYK colour listed none, unlike the
comment list and the drawing. Non-FreeText comments now read /C by the
appearance builder's rule (one entry grey, four CMYK with a non-number as 0
and a reference unreadable, finite and clamped), with the three-number
fallback reading referenced entries.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn
---------
Co-authored-by: mtlcl410 <chuanlin@niar.org.tw>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
* M9: redraw named-layer signature status layers
- /N drawing one Form that holds n1 and n3: n1, n3 and n4 redrawn for the state
- copies made once per original and state; originals never edited
- Lucide icons; captions in Helvetica, embedded Inter, or craft-fonts outlines
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: draw signature states in the display copy, exports and print
- marks follow the bytes shown; a changed verdict redraws after a metadata edit
- background opens pick up the trust and captions current at commit
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: status captions in the interface language
- the three captions in all 22 catalogues
- Signatures panel colours from sign::status_rgb
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: signature badge in the widget's corner
- a quarter of the shorter side, 48pt cap; outline only under 32pt
- dropped for a drawn valid state; bottom-right where the appearance draws one
- sign_list reports verdict_shown; parity and roadmap
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: keep Arabic signature captions in logical order
Pass raw RTL catalogue text to the signature appearance shaper so UAX #9 is applied exactly once. This keeps the rendered word order and exported /ActualText consistent.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M2: read /ActualText over painted paths and pictures
- A replacement that marks no glyph reads where it paints, cut to what is visible and along the way it is drawn.
- A span the page content leaves open ends before the annotations.
- OCR and scan field detection still count such a page as having no text of its own.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M8: redaction strips /ActualText around paint it clips
- A path or shading written again under a clip counts as changed, so a partly redacted word drawn as outlines leaves no name in the file.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: recognise only layer forms that draw n1 and n3
- Settle on the one form holding both first, then read its content once per call.
- Skip an /N that is its own layer form; copies keep the layer's /OC.
- A verdict counts as drawn when any visible widget shows it.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: keep the signature badge and redraw wherever a state changes
- The badge stays for every state; its mark sits bottom-right as the widget lies on the page.
- An edit that changes a verdict redraws every page; captions apply before startup files open.
- Print, the CLI's render and the repair log follow the display copy.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: restore the attribution usage the rebase dropped
- Usage lines for the three icons, Inter and the craft-fonts input; ATTRIBUTION.md rebuilt from them.
- Roadmap and localization notes for this round.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: pin signature field names on a nested form
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: bound the signature field walk
- kids share their parent's name and type instead of each copying them
- a widget stays listed under every field that claims it, as one shared copy
- a field written in place in a shared /Kids array is walked once
- caps of 20,000 fields, 100,000 entries and 4096-byte names; no states drawn past them
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: keep a document signed when the field walk stops early
- list_cached adds a signed row of unknown validity for the fields the walk didn't read
- Save As and actions then append, and Optimize, Sanitize and full rewrites are refused, as for any signed file
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M8: removing hidden content no longer strips the names of shadings
- With no regions to clip, a shading is left alone instead of wrapped and marked clipped
- clean_replacements skips scopes already marked, so deep nesting stays linear
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M2: read a picture's /ActualText over the whole picture
- draw_image's transform maps pixels, not a unit square, so the text sat on one pixel in the corner; the test now draws a 2x2 picture
- Painted grows in place instead of being copied through an Option
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: cap the bytes of names the signature field walk keeps
- A kid's name repeats its parent's, so one long name over 20,000 kids came to 80 MB; the walk now stops at 4 MiB of names and counts the rest as unread
- Cover the widget written into a shared /Kids array and the field cap among kids, which no test caught
- sig_fields is private again, and the cap docs say what happens past each cap
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: skip status-layer work that changes nothing; fix tests that could not fail
- show_status_layers and has_status_layers return before reading the form when nothing is signed, so an unsigned form no longer walks every field on each edit
- revalidate and draw_captions leave documents with no drawn state alone, and no longer copy the signature list to update it
- Scan form detection reads the page's text once; comment and badge tips share one hover rule
- Tests: drop a table row that repeated another, stop taking an expectation from the code under test, stop comparing an Arc with itself, give bare asserts messages
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: test the signature field name cap at the engine boundary
- A 4,096-byte name is read and blocks a full rewrite; at 4,097 bytes the list holds the unread-fields row and a full rewrite is still refused
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: test signature states beside fields the viewer draws
- One display copy holds both a field's drawn appearance and the signature's state.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: draw Thai and Devanagari status captions in their own script
- script_of names Thai and Devanagari, so a craft-fonts face meant for either draws the caption as outlines; without one it stays English.
- Localization, parity and the craft-fonts usage line list the new scripts.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M2: paint left out by an exclusion mixes its /ActualText replacement
- A replacement placed by outlines or pictures, some of them excluded, fails filtered extraction as one with excluded glyphs does.
- Glyphs still place a replacement that has them.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: a long-named field that can't hold a signature leaves the walk whole
- A leaf of another type passed over for its name is no signature field and has none below it, so an unsigned form stays unsigned.
- A signature field, or any field with kids, still counts as unread.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: status captions use document faces only
- Each script takes the face PdfCraft writes it into documents with, so Chinese stays English although the pinned craft-fonts' interface-only Chinese face is meant for Hani.
- The craft-fonts usage line names Devanagari: the pinned revision has a face for it, and Hindi captions are drawn in it.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: refuse a new signature field the field walk can't read back
- Signing adds a field only when the walk reads the whole form with it: past a cap the signature would be listed as unread fields, and its name could repeat an unread field's.
- A field the walk already reads is signed as before.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: refuse a new signature field with a blank name
- The walk lists no field without a name, so signing now also requires the walk to list the new field: one named only with spaces or NULs would be a signature nothing shows.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: an unnamed signed field or an unreadable form counts as unread
- A signed field with no usable /T, or an /AcroForm or /Fields of the wrong type, cuts the field walk short: the document keeps its unread-fields row and stays signed.
- Signing refuses a blank new field name before it adds the field, so the refusal still says why.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: no display copy when no signature state is drawn
- display_bytes_for makes a copy only when it added an appearance or drew a state, as the app does.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: the verdict mark stays on the page
- A widget past the crop box takes its mark in the part on the page, or none when too little of it is there.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: typed values stay drawn while a signature redraws every page
- A form edit that changes a signature's state puts its values back in unbaked after the pages are invalidated.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: the action, Save As and shading tests check their effects
- The signed action and Save As tests reopen the output for the title and the comment; the shading test checks its clip.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: values typed earlier stay drawn while a signature redraws every page
- A form edit that changes a signature's state keeps every value still waiting on its page, not only its own.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: comment and content edits keep typed values drawn too
- An edit to one page's comments or content that changes a signature's state moves no page, so the values still waiting on their pages stay pending, as after a form edit.
- The pending-value test runs a field deletion and a comment after a fill, under a certification that allows the fill; its messages say what it checks.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: the language-change test skips without catalogs
- Like the other language tests, it returns early when the build has no craft-i18n catalogs.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
* M9: signed fields behind kids without a name count
- A kid with no /T but kids of its own is walked as a field node, so a signed field under it is listed by its full name.
- An unnamed kid claiming a signature its field doesn't have cuts the walk short, so the document stays signed and keeps its unread-fields row.
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
---------
Signed-off-by: Chiranjeevi U <244287281+chiranjeevi-max@users.noreply.github.com>
A quad counts only when all 8 entries are present, numeric and finite.
Anything else contributes nothing — never folded, shifted or zero-filled
into a box the document does not describe. With no usable quad the
existing /Rect fallback runs, and with neither the mark stays unreadable.
The rule lives in one helper, geom::quad_points::usable_quads, and redact,
render-inspect, annot summaries and annot appearance drawing all read
through it, so the outline shown is the area apply removes. Redact also
follows indirect numbers in /QuadPoints now, which it used to drop.
The text layer asked the router whether the press's owner kept its drag,
link following asked it which link held the press, and the Link tool
started a new link from a press any link held, since the router kept a
declined drag's capture.
- `PageRouter::drag_started`: a drag the owner declines (text markup;
with the Link tool, a link) is nobody's once it starts, on the page it
began on. The Link tool draws a new link only from a drag nobody
holds.
- `PageInput` carries the press (`PagePress`) and whether its drag is the
page's text's (`text_drag`): the text layer and link following read
them, and `PageRouter::owner` goes. Only the page view reads the
router now.
- Image pick acts on a press nobody holds: a link's click follows the
link only, and picks no picture under it (the user's ruling).
- The I-beam drops over a link only where a press would go to it, the
top hit under the pointer (the user's ruling): the tools that select a
link's text show it there.
- `PageText::glyph_at` is the one test for the text under a point, for
the text layer and Redact's boxes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* M1: a crypt filter selected by reference is used
A stream can name its own crypt filter, and every part of that can be indirect. cos read only the
direct forms, and took anything else for no name, which is /Identity. So a stream selecting a filter
by reference was saved in the clear in a file meant to be encrypted, and in a file from elsewhere
its ciphertext was read as data. The /Encrypt dictionary's /StmF, /StrF, /EFF, /CFM, /Filter,
/EncryptMetadata and a filter's /Length had the same fault, and /StmF by reference left every
stream undecrypted. A stream's /Type and a signature dictionary's are read through references too.
transform now reads these from the document, so a full save encrypts before it renumbers: the
references in what it reads have to be the document's. Dropping a crypt filter that new protection
doesn't define comes before the walk, so what it copies out of a reference is encrypted too.
Loading can re-enter here, and LoadGuard ends a cycle, which reads as absent. A chain longer than
any decoder takes names no filter: its entries would be followed for every stream sharing it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M2: a stream with a crypt filter of its own is drawn
The renderer decrypted every stream with the document's filter and then failed on /Crypt as a filter
it couldn't decode, so a stream naming its own filter read as nothing, however it was spelled, and a
page whose content was such a stream stayed blank. It now uses the filter the stream names, /Identity
without one, and /Crypt is nothing further to decode (hayro-syntax patch 30).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: tests for a crypt filter's place among the others
A lone parameter dictionary is the first filter's, so /Crypt behind another filter has no name of
its own, and an array too short for /Crypt's entry stays as it is when the filter is dropped.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: encryption reads every legal form, and a full save keeps them
From a review of the crypt filter fix.
The renderer read a stream's own filter from the form /DecodeParms had to match the form of /Filter,
so [/Crypt] with a lone dictionary, an everyday spelling, read as /Identity and the page stayed
blank. Parameters are now taken in either form, which also gives [/FlateDecode] its predictor.
It also refused a V4 file without /StmF or /StrF, which are optional, and used a /CF entry named
/Identity, which is never one. A chain past what cos decodes names no filter there, so it names none
here either (hayro-syntax patch 30).
A full save lost what a direct /Encrypt refers to, and kept its references under the old numbers, so
nothing in the file read afterwards. /O or /U given by reference were decrypted and encrypted again
under a new number, so the file it wrote no longer opened. What /Encrypt and /ID refer to now stays
as stored. /ID by reference, which has to be direct, is read, and written direct.
A signature dictionary is known by a /ByteRange given by reference, and a null or dangling /Type or
/Subtype is an absent one. References to references are followed in Document::resolve, so /Name by
way of two no longer saves a stream in the clear. New protection drops every /Crypt in a chain.
An object stream's /DecodeParms can be given by reference.
Reading what decides how an object is treated can load more objects, each doing the same, which a
file could make a tree that doubles with every level once the cache lets go of it. What is loaded
for one of these no longer follows its own.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: what a read follows is bounded by a budget, and nothing shared is copied per stream
From a review of the fixes before this, all in them.
A flag that kept what is loaded for a selector from following its own stopped the fan-out, but a
legal file lost object stream members to it: read first through a selector, an object stream with
parameters by reference was kept undecoded, and a full save wrote nulls without saying so. A budget
replaces it: one read or write of an object, with all it loads on the way, follows up to 32
references, which is more than any object needs when all of it is by reference. Past that they
read as absent, so a file's ladder of selectors still stops, and nothing a real file holds is lost.
Finding out whether a dictionary is a signature's loaded objects for every dictionary of an object,
and a load that fails takes a scan of the file, so one read could hang. Only a dictionary with a
direct string /Contents is asked now, and the budget bounds those.
/ID written direct copied every entry, so a 1 MB file naming a large string thousands of times ran
out of memory: it is at most two strings now. Dropping a crypt filter copied a shared /DecodeParms or
/Filter into every stream, 1 GB from a 1 MB file: of what's shared only filter names and the
parameters decoders read are copied now, through Document::with_direct_parms.
The renderer skips /Crypt in a chain instead of copying the data for each entry.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: only an object itself follows references, and a failed scan is remembered
From a review of the budget.
Following a reference while walking deep inside an object added that depth again for each object
loaded, which overflowed a 2 MiB stack on a file under 10 KB and took the process with it, past any
catch_unwind. References are now followed for the object itself and never for what is nested in it.
A stream can't be nested, and a signature dictionary nested in another object reads as it says
directly, as it did before this PR. walk is back to following nothing.
A reference that fails to load scans the file, and nothing remembered that, so a 1 MB file took
minutes to save. What a scan didn't find is kept for the document: the file doesn't change.
Filter names copied out of a shared chain are bounded, since a name can be any length. /ID keeps each
entry in its place, or the key made from the first entry changes. direct_id's comment was on another
function.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: tests with no deadline a busy machine can reach
Wide margins on the two that time what they guard. A test of dictionaries nested in an object goes:
nothing nested follows a reference now, which the small-stack test covers.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: a crypt filter past what a read may follow is the document's own
Past the budget a reference reads as absent, and a crypt filter with no /Name is /Identity, so a stream
that selected one by reference had its ciphertext read as data. What can't be told takes the document's
filter, as a /Filter that can't be read does.
Found by CodeRabbit.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: a read refused, not a budget full, is what leaves a crypt filter unknown
My last commit took a read that used up all it may follow for one that was refused, so an /Identity
stream read at exactly 32 follows was decrypted to garbage. Refused reads are counted now, and only
one on the way to this stream's /Name says anything about it.
Found by CodeRabbit.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* M1: a save keeps the handler, the key and the permissions
Under every algorithm and by either kind of save, `/Encrypt`, `/ID`, the file key and the permissions
come back as they were. No test held that. `/ID` by reference is held through an incremental save
too, which leaves it as it was.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
* cos: encrypt an edited or added object whatever /Encrypt names
stored_as_is now also requires the object to be unedited, so an edit of
an object /Encrypt or /ID refers to, or a new object given a number they
name, is encrypted on both saves. encryption_members skips numbers with
no object behind them and streams, which those dictionaries never hold.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: FredApps <153173854+FredApps@users.noreply.github.com>
Review of #3858 (aiongg):
- An area-shrunk image with a soft mask, a stencil's ink included,
built its full-resolution RGBA before shrinking. A 10718 x 13701
stencil at page size peaked at 1.16 GB (587 MB of RGBA). It is now
premultiplied a source row at a time as it is averaged, and the
shrink works a target row at a time, so it peaks at 1.03 GB, as the
nearest-neighbour path did. Same bytes; about 5% slower per shrink.
- An image whose f32 scale passed 1 only by rounding was smoothed
bilinearly and blurred by half a pixel at a half-pixel offset. It is
now smoothed only above 1.01.
- A shrunk /ImageMask stencil keeping its thin strokes (#4800) is now
tested.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
A soft mask no larger than its area-shrunk image is sampled onto the
image's grid, and it was always sampled nearest-neighbour: a mask that
asks for /Interpolate became a hard step where main drew a ramp
(jpeskov's 64 x 64 image at 32 x 32 under a 2 x 2 mask). An interpolated
mask is now blended bilinearly onto the grid, centres aligned; one
without /Interpolate is still sampled nearest, which keeps the
colour-fringe fix.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Scanned pages looked thin and broken at screen size. An image that does not
ask for /Interpolate (most scans) was pre-shrunk with nearest-neighbour since
about one sample in ten and dropped most strokes of its text, and the nearest
sampler then read the shrunk raster again at a fractional offset.
- Shrinking (vendored hayro patch 21): non-interpolated images outside Type 3
glyphs are area-averaged (area_shrink: each device pixel the
coverage-weighted mean of the samples it covers, 16.16 fixed point whose
weights sum to exactly one, premultiplied when masked) to their snapped
device rectangle and drawn 1:1. /Interpolate governs smoothing when an image
is enlarged (ISO 32000-2 8.9.5.3); averaging adds nothing between samples
and drops none. PicScale's Box/Area filters were not usable: shrinking, they
average a window four target pixels wide.
- Enlarging (patch 28): an image of page-scan size (512+ samples on its
shorter side) is drawn bilinearly when enlarged, so a zoomed scan has no
staircase edges; icons, QR codes and pixel art keep their hard pixels.
- A snapped image whose shrink failed keeps the full transform instead of
being drawn at its source size (latent in the interpolated path too).
Measured on a 13-page 300 dpi scan at 96, 120 and 192 dpi: every rendered
sample is within 1 of the exact area average (it was up to 255 off, 17-23%
of samples by more than 1). Bilinear zoom costs nothing measurable (four
1024 px tiles at 400%: 50 ms, nearest 48 ms; bicubic was 267 ms).
Review fixes:
- a tile snaps a shrunk image's half-pixel edges where the whole page does
- a scan shrunk one way is smoothed the way it is stretched
- a smaller soft mask doesn't let transparent colour through the area shrink
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* M5: keep Fill & Sign editing on Enter and preserve line breaks (#5850)
* M5: preserve typewriter whitespace through readers and edits (#5850)
* M5: retain direct-subtype comment listing for Fill & Sign fix (#5850)
Windows exporters map the hyphen of an Arial they don't embed to U+00AD in
/ToUnicode. The CFF standard substitute has no soft hyphen, so the CID was
taken as its glyph index and drew an unrelated glyph (an Ë, or ! in bold).
ISO 32000-2 Annex D.2 calls the soft hyphen typographically the same as
the hyphen, as patch (30) already reads WinAnsi 0xAD: draw the
substitute's hyphen. The text keeps U+00AD.
* A rebuilt xref finds an object whose header names another generation (#5580)
`poppler-85140-0.pdf` is 340 bytes with no cross-reference table, and the
header of its one page reads `3 18446744073709551616 obj` while the page tree
points at `3 0 R`. Before #427 the digits wrapped and 2^64 wrapped to exactly
0, so the header read as `3 0 obj` and the file opened by accident. Once an
overflowing integer became a real, the object was unreachable and the file
stopped opening at all, which `cargo xtask check` reports as a regression.
The generation is not really the point. `3 99999 obj` with the same page tree
is refused in exactly the same way on main -- the control for the new test
fails on that row first, with "page 1 does not exist" -- so this is a
mismatched generation in a rebuilt table, not an integer overflow. A table
rebuilt by scanning the file has no revision history to tell two generations of
an object apart, and a file that needs rebuilding references everything as
`N 0 R` whatever its headers say.
So, in the reconstruction path only:
- a generation number that cannot be read is taken as 0, the value such a
file's references use (`read_object_header`). A generation is at most
65,535 (ISO 32000-2 §7.5.4), so there is nothing to lose by it;
- every scanned object is also filed under generation 0, with `or_insert` so
a real `N 0 obj` is never displaced by the alias;
- the object is read back behind the same lenient header, since reading it
parses the header again and the strict identifier check rejected it
(`read_repaired_body`, gated on `repaired`).
Reading numbers anywhere else is unchanged, and a table read from the file's
own xref keeps the exact identifier match. The scan already files objects found
in object streams under generation 0, and cos's table parser already takes an
unreadable generation as 0, so this follows what the code does elsewhere.
The test covers generations 0, 99999 and 2^64 with no table and no `startxref`,
and asserts the page is found at its own size. Its fixture is built in the test
rather than taken from the corpus, so it holds without the pinned checkout.
* The generation-0 stand-in is one key, not a second object
Two consequences of filing a scanned object under generation 0 as well,
both from review.
`XRef::objects` walks the table's keys, so an object with a stand-in came out
once per key: a document whose page tree cannot be read is recovered by looking
for objects that are pages, and it reported the page twice. Enumeration now
yields one object per location, after the sort it already does. Both keys stay
for lookups; only this walk is deduplicated.
And `or_insert` never replaces, so a later `3 1 obj` moved the exact `3 1` key
to the later body while the `3 0` stand-in stayed on the earlier one -- `3 0 R`
and `3 1 R` would then read different objects. The scan now tracks which
generation-0 keys are stand-ins: a real `N 0 obj` takes the key and keeps it,
and a later header for the same number replaces a stand-in.
The tests check both through what comes out: page 2 must not exist for a
single-page file recovered without a page tree, and with two `3 1 obj` headers
the page comes back at the later body's 300x150 rather than the earlier
200x100.
* M2: the repair scan keeps its place on a non-header, and an object stream's first member is enumerated (#5580)
- read_object_header's lenient path works on a clone, so `42 3 0 obj` no longer costs the
header after the stray number (CodeRabbit, minor).
- XRef::objects deduplicates by location and object number: an object stream and its first
member share (offset, 0) and are two objects (CodeRabbit, minor).
- vendor/README.md: hayro-syntax patch (34) and its tests.
Both new tests fail with their fix reverted.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Brandon Thomas <echelon@gmail.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
* M2: a shrunk image on a turned or mirrored page snaps to whole pixels (#5530)
hayro patch 14 (`snap_minified_image`) shrinks an interpolated image once
to its whole-pixel device rectangle and draws that 1:1, instead of
shrinking to a rounded-up size and resampling again at a fractional
scale and offset. It only accepted an upright transform (a > 0, d > 0,
b = c = 0), so every image on a page under /Rotate 90, 180 or 270 -- and
any image placed turned or mirrored by its own matrix -- still took the
double resample. That is #5530: a scanned page that matches PDFium
upright drifts and softens when the same page is rotated.
The snap now accepts every transform whose axes lie along the device's
(the eight quarter-turns and mirrors) and returns the 1:1 transform
that draws the shrunk raster from the snapped corner, one source-axis
step a whole device pixel, in whichever direction that axis runs.
Skewed and freely rotated images keep the old path.
On a synthetic page (crop box and scale on whole pixels, image at
fractional coordinates), /Rotate 90, 180 and 270 renders turned back
differed from the upright render in 72% of pixels, by up to 200 grey
levels; now they are identical. Non-interpolated images were already
identical and stay so.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* M2: snap only when the dropped skew is invisible, and only a resize that succeeded
Review of #5640:
- The snap judged an image axis-aligned by a tolerance on its
coefficients (1e-4 of the scale). For a very wide image a skew that
small still moves the far edge by more than a pixel (40 000 samples
at 4e-5: 1.6 px), and the snap flattened it. It now measures what it
drops: how far each off-axis term moves the far edges, at most a
hundredth of a device pixel (SNAP_SKEW). Upright and turned alike.
- A resize that fails hands back the source raster at source size; the
1:1 snapped transform then drew it at that size. The snapped
transform is now used only when the shrink produced the snapped
size; otherwise the full transform, as before.
- The mirrored case of the edge test drew a uniform image, which looks
the same mirrored; it now also mirrors a half-black image and checks
which side the black lands on.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* M2: the turned-page test draws every kind of image the snap reaches
The /Rotate oracle test drew one 8-bit grey image. Stencil masks (CCITT
scans often are one), 1-bit images and images with a soft mask reach
the snap through other paths, so it now draws all five: 8-bit and
1-bit grey, a stencil mask, a soft mask of the image's size and one of
another size. On main, every interpolated kind is off by 113-217 levels
over 63-73% of the image when turned, and so is a non-interpolated
image with a smaller soft mask (110 levels, 16%): hayro patch 15
filters such a mask whatever /Interpolate says, so it is snapped
upright and was not when turned. All are identical with the fix; the
other non-interpolated kinds were already identical and stay as guards.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Co-authored-by: Brandon Thomas <echelon@gmail.com>
A region's location, a refinement's offset, a symbol's corner, a Huffman
range line and a decoded integer of 2^31 could each overflow: a panic
wherever overflow is checked. The last four wrap, as a release build did.
Bitmap::combine saturates, which comes to the same: a side is at most
65,535, so a location that overflows is past the end of any page. What is
drawn doesn't change. Patch (12), after the numbers #5491 and #5569 take.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
`IndirectObject<f32>` read an object holding `6 0 R` as the number 6, so `/Decode [11 0 R 0]`, with
11 naming 6 and 6 holding 1, read as 6, and `/W` gave glyphs such widths. As anything but a number,
such an object was lost.
`XRef::get_with` is how every reference is read, to an object stored on its own or in an object
stream, so it now follows such objects in a loop, up to 32 references as `Document::resolve` does in
#5548. A loop takes no stack however long the chain, and a cycle runs out of references and reads as
a missing object, as a reference to nothing does: the image with such a `/Decode` isn't drawn, as
with `/Decode [99 0 R 0]`.
An object stream isn't reached that way: it has to be a stream stored as that object, and following
a reference to one stored inside another let a 1 KB file run out of stack. `XRef::objects` leaves
such objects out, or a page came out once more for each one holding a reference to it, and a comment
inside a reference counts as white space, as it does everywhere else.
Reading an object stream's index now counts against the 64 nested loads, and reads its dictionary
alone. That is older than this branch, which only made it slightly worse: a chain of object streams,
each with a member of the next for its `/N`, `/First` or `/Length`, recursed with no limit, holding a
copy of the chain at each, and aborted on 750 KB with an 8 MiB stack, or 250 KB with 2 MiB, in a test
build. Parsing the stream read `/Length` as well as `/N`, two ways to the next stream's index, and a
failed index isn't remembered, so the work doubled at each stream: 20 streams in a ring took 20 s on
`main`. ISO 32000-2 7.5.7 keeps an object stream's `/Length` out of object streams, so no legal file
has a `/Length` chain. Nothing forbids `/N` or `/First` by reference, though no writer I know of makes
such a chain. Past the limit it reads as missing unless a stream within 64 of it has been read.
`/W` and `/W2` with their list by reference are tested too.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Colour spaces already had tests of this through their bases. `/Decode`, in the renderer and in image
export, `/W`, `/W2` and an Indexed space's table hadn't: each read now has such a reference in its
test, and ends.
These hold that the read ends, not what value it comes to. A reference to a reference in a number
array reads as the first number of that reference in the renderer (`/Decode [11 0 R 0]`, with 11
naming 6 and 6 holding 1, reads as 6). That is older than this branch, in `IndirectObject::read` for
an object stored on its own and `ObjectStream::get` for one in an object stream.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
The depth limit didn't hold. An ICC profile read was kept whole, with the alternate it fell back
to, and a later read took it without counting its levels. A page selecting the last of a chain
first built each space on the one before, and no read was deep: 20,000 levels, and the stack
overflowed painting with it. In the other direction, a profile met at the limit kept the fallback
it got there, and a read nearer the top got that instead of its alternate.
Both come from keeping a result that depends on the depth. What's kept now is what the profile
itself reads as, one level whatever it is, and the alternate is read where it's met.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Reading an object already being read is refused, which ends a cycle but not a chain. 5,000 spaces
each naming the next, 180 KB of file, overflowed a 2 MiB stack and aborted the process, through a
Pattern's underlying space, an Indexed base, or a Separation's or DeviceN's alternate. An ICC
profile's alternate is the same recursion. Indexed, Separation and DeviceN could already do this;
the fix for Pattern added a way in.
A legal file goes five levels at most. All five ways through count against the one limit, in
ColorSpaceType::new, so what comes in from outside is unchanged.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
What a page has left is shared by all of it, so it says nothing about a stream that isn't JBIG2: a bad
Flate or JPEG mask dropped its picture on a page that had spent its allowance, and a failing image of
another kind raised a false "content skipped". Both ask about the stream now.
The allowance also outlived the page on its thread, and a Context used again kept it. interpret_page
sets it, and a guard ends it with the page.
Found by CodeRabbit.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Rows are charged by the symbol, so an empty class decoded its collective bitmap for nothing: 65,535
rows a class, a thousand classes a dictionary. 806 KB took 196 s. It steps over the bytes instead.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Without its mask a picture shows what the mask hides, so the page leaves it out, as export does. Any
other unreadable mask still leaves the picture, which is the renderer's tolerance for bad masks.
What an export may hold is a function of its own, tested down to the step and at the top of the range.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
From a review of who reads a refusal.
The rule is to leave it out and say so, and it held on some paths only. An image whose JBIG2 mask is
refused no longer comes out opaque. The first image past the allowance reads as that and not as
corrupt. A page reports what it left out. The Office warning stopped blaming forms. Redaction refuses
the run, leaving the document as it was: removing a readable image whole would take what no mark
covers with it, unreported.
The 2 GiB an export holds is twice the document if that is more, so a large honest file loses nothing.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
One image has its own limit, about 6 s to 17 s, but nothing bounded a file of thousands of images
made to reach it: an operation took that long for each, and an image sharing /JBIG2Globals decodes
them again.
Image::decode_within (hayro-jbig2 patch 11) spends from what a run may still do, starting with its
page's pixels, and charge_reading charges reading a stream and its globals, 4 steps a byte, before
anything is parsed, so an image that fails has paid too. pdfcraft_filters::decode_jbig2_within takes
it, and ImageBudget in cos is that allowance: 2^34 steps, about 1,000 scanned pages, and 2^13 more for
each byte of the file, so a long scan is read whole. An image past it spends all that's left, and
later ones aren't read, globals included.
Optimize leaves such an image as it is and counts it in Report::images_refused. Image export leaves it
out, with the reason, and stops at 2 GiB of files held. Office export shares one allowance, leaves the
picture out and says the page was truncated. Redaction removes it whole, as any image it can't read.
Rendering gives a page's images 2^30 steps between them, inside the watchdog, and each page starts
afresh in Context::new as its other budgets do (hayro-syntax patch 31, hayro-interpret patch 73).
It's a thread-local, unbounded until a page sets it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
From a review of the work count. An item with no pixels was charged a step, though reading it can take
hundreds of decisions, so a 22,515-byte PDF of refined text instances of no size stayed inside the
limit and took 730 s to render. Empty height classes and export runs weren't charged at all, and 19 KB
of them took 47 s. Each integer an item reads now costs what one takes at worst, 38, so a decision
never costs more than a pixel. A full region of 10,000 instances is 0.14% of the limit, so a real file
doesn't notice.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
From CodeRabbit on the work count.
A symbol with no rows cost no work, though it is decoded all the same, so a stream of thousands of
dictionaries of such symbols, exporting none, went uncounted. Each symbol now costs a step more than
its pixels.
A refined text instance was charged after it was decoded, so one could still be 2^28 pixels past what
was left before the decoder refused. It's charged once its size is read, before anything is allocated.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
The Pattern fix opened a recursion path: a Pattern's underlying space is now followed, as an Indexed
space's base always was. Self-references and cycles between the two end as a space that can't be
read.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Since the renderer now draws an image with /Decode [7 0 R 0], export disagreed with it. Its check of
which way round a stencil mask or a CMYK JPEG is compared the two numbers as given, and a reference
reads as none, so the file came out a negative of what the page draws.
Tests for the function arrays the previous commit's tuple fix also covers: a function's /Domain,
/Range, /Encode and /Decode are read a pair at a time too.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Two more ways a reference was lost in the same readers. A Pattern space read its family name twice,
which took the underlying space when that was a name or a reference, so an uncoloured pattern took
its components as RGB: [/Pattern /DeviceCMYK] drew a cyan as red, direct names included (patch 72).
Tuples of array items, which /Decode, /W and /W2 are read as, took a reference at their start for the
whole tuple. A tuple can't be given by reference, so it was lost and the array ended there: an image
with /Decode [7 0 R 0] wasn't drawn, and CID widths fell back to /DW. A tuple now reads its items
directly, and each follows its own reference (hayro-syntax patch 32).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
A colour space [/Indexed /DeviceRGB 1 5 0 R] whose table is a string in object 5 couldn't be read:
the table was tried as a stream first, and a failed read uses up a reference, though not a direct
object, so nothing was left to read it as a string. The space then drew in grey from the index, so
a palette's colours were lost. The table is now read once, as whichever it is (hayro-interpret
patch 71).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Each JBIG2 bitmap is bounded, but nothing bounded how many a stream asks for, so a few hundred
bytes could tie up a render worker for minutes, and CodeRabbit raised the same on #5461. Measured
through pdfcraft-cli, before and after:
- one halftone segment, a 795-byte PDF: 265 s, now refused at once;
- 66 halftones over patterns 1 wide, a 3,894-byte PDF: about 330 s, now refused at once;
- about 226,000 generic regions behind nested Flate, a 923-byte PDF: unfinished at 40 s, some
88 hours by extrapolation, now 4.8 s;
- 8 dictionaries of symbols of no width, a 983-byte PDF: 81 s, now 0.7 s;
- about 1,048,000 generic regions of no width, a 34 KB PDF: unfinished at 90 s, now 2.6 s;
- an aggregated dictionary over 2^20 symbols, a 713-byte PDF: unfinished at 90 s, now 9.1 s;
- 10,000 instances of an 8192 × 8192 symbol, an 18 KB PDF: 64 s, now 3.2 s;
- 30 generic regions of no data: 48 s, now 4.7 s.
A stream may now ask for 2^30 units of work: four of the largest pages, about 6 s on data the
decoder predicts and about 17 s on data it can't, inside the viewer's 20 s watchdog. Decoding a
bitmap costs a unit a pixel and 4 a row, since a row costs time at any width. Copying one costs a
unit a word and 1 a row, so a tall thin bitmap costs its rows. Each item is charged before it is
decoded, apart from what is known only as it goes: new symbols and text instances are charged in
their loops. An aggregated symbol is charged for the symbol table it rebuilds. Past the bound the
image isn't drawn, as with the other caps, and the rest of the page is.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
Each JBIG2 bitmap was bounded on its own, but a few kilobytes could still exhaust memory:
nothing bounded what a page's segments hold for later ones, or how far one segment could
multiply them. Measured on black-box streams, peak memory before and after:
- intermediate regions, 16 in 774 bytes: 514 MiB, now 98 MiB;
- an 8 MiB symbol exported 1,200 times, a 2,989-byte PDF: killed at 8 GiB, now 79 MB;
- dictionaries of zero-width symbols: 781 MB, now 72 MB;
- dictionaries retaining their coding contexts, 1.1 MB: 2.89 GB, now 71 MB;
- 65,535 references to one dictionary, 78 KB: about 17 GB, now 6 MB;
- a halftone grid of 16,384 cells a side, 98 bytes: 1.1 GB, now 2.4 MB;
- a pattern dictionary of 65,535 patterns, 48 bytes: 539 MB, now 15 MB, and it still draws;
- a custom Huffman table behind nested Flate, a 1,297-byte PDF: killed at 8 GiB, now 278 MB,
which is mostly the decoded stream;
- 11-byte segments behind nested Flate in a stream and its globals, a 4,765-byte PDF: 5 GB, now
602 MB, which is mostly the two decoded streams;
- an Indexed image whose page header claims 2^20 a side, a 743-byte PDF: aborted asking for
137 GB, now 23 MB;
- a chain of 4,000 /JBIG2Globals streams that are JBIG2 themselves, on a 2 MiB stack: overflowed
it and aborted, now 24 MB.
So PageState counts what it stores: regions, pattern and symbol dictionaries and Huffman
tables, with bitmap headers, retained contexts and a charge per item, up to 64 MiB, two square
bitmaps of 16,384 a side. A dictionary's new and exported symbols count against what is left as they are
made, not once it is stored. A segment may refer to at most 2^20 symbols, checked before any are
collected. A halftone grid has at most 2^25 cells. A pattern dictionary keeps at most 16 MiB of
shifted copies, which only speed up drawing, and none that wouldn't fit what the page has left. A custom Huffman table has at most 2^16 lines, and a
stream with its globals at most 2^20 segments and 2^22 references, checked as they are read. A
page past the bounds on a bitmap is refused when the stream is opened, since callers size their
output from its header before the page bitmap is made. And in hayro-syntax, a /JBIG2Globals
stream that is itself JBIG2 isn't decoded: globals are raw segments, so it reads as globals that
can't be decoded.
An image past a bound isn't drawn, as with the other caps, and the rest of the page is. This
bounds memory, not time: decoding work has no total yet.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
The vendored hayro-syntax ran PNG predictors through the bit-level
BitChunks/BitWriter machinery TIFF predictors need, although PNG filters are
defined on bytes (ISO 32000-2 §7.4.4.4, PNG specification §9). A 993 x 936
RGB image took about 63 ms to unfilter whatever its row filters; undone on
byte slices it takes about 3 ms (Up) to 16 ms (Paeth) in a release build.
It also fixes a row that ends part-way through a pixel (three 4-bit samples
at an odd width): the bit-level path dropped its last byte, each later row
started a byte early and the picture came out sheared.
TIFF predictor 2 keeps the old path. Vendored hayro-syntax patch 29.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SqmHYx8FiWM5PcsoiErgp9
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