With this, looking at page 2 of pdf_reference_1-7.pdf no longer crashes.
Why did it crash in the first place? Because due to this bug, CFF.cpp
failed to parse the font program for the font used to render the `®`
character. `Renderer::render()` adds all errors that are encounterd
to an `errors` object but continues rendering. That meant that the
previous font was still active, and that didn't have a width for that
symbol in its width table.
SimpleFont::draw_string() falls back to get_glyph_width() if there's
no entry for a character for a symbol. `Type1Font::get_glyph_width()`
always dereferences `m_font` in that method, even if the font has
a font program (and m_font is hence nullptr).
With the off-by-one fixed, the second font is successfully installed
as current font, and the second font has a width entry for that symbol,
so the problem no longer occurs.
There were two problems:
1. parse_compressed_object_with_index() parses indirect objects
without going through Parser::parse_indirect_value(), so
push_reference() / pop_reference() weren't called.
Manually call them, both for the indirect object containing
the object stream and for the indirect object within the
object stream.
2. The indirect object within the object stream got decrypted
twice: Once when the object stream data itself got decrypted,
and then incorrectly a second time when the object data within
the stream was read. To fix, disable encryption while parsing
object stream data (since it's already decrypted).
The test is from http://opf-labs.org/format-corpus/pdfCabinetOfHorrors/
which according to readme.md at the same location is CC0.
Using a special instruction to access global variables allows skipping
the environment chain traversal for them and going directly to the
module/global environment. Currently, this instruction only caches the
offset for bindings that belong to the global object environment.
However, there is also an opportunity to cache the offset in the global
declarative record.
This change results in a 57% increase in speed for
imaging-gaussian-blur.js in Kraken.
This counter is incremented whenever a mutating operation occurs
within the environment's set of bindings.
It is going to be used by GetGlobal instruction to correctly invalidate
cache when global declarative environment is mutated.
This prevents SVG elements referenced by "use" being repeatedly cloned
in many redundant cases. Pages that use a large svg "sprite" that then
is referenced many times with "use" elements would load extremely
slowly, or crash the page.
The `document_fully_loaded` event should use the adjective "completely"
so as to match the spec and code convention. See
`Document::is_completely_loaded` and `m_completely_loaded_time`.
PDF files can be linearized. In that case, they start with a
"linearization dict" that stores the key `/Linearized` and the value
`1`. To check if a file is linearized, we just read the first dict, and
then checked if it has that key.
If the first object of a PDF was a stream with a compression filter
and the input PDF was encrypted and not linearized, then us trying to
decode the linearization dict could crash due to stream contents being
encrypted, decryption state not yet being initialized, and us trying
to decompress stream data before decrypting it.
To prevent this, disable uncompression when parsing the first object
to determine if it's a lineralization dictionary.
(A linearization dict never stores string values, so decryption
not yet being initialized is not a problem. Integer values aren't
encrypted in encrypted PDF files.)
These three lines were added in commits 41d5531, 0f7a651 and 97aca8f all
the way back in June 2020, and went unnoticed until Lucas pointed this
out during my refactoring.
These too should be sorted alphabetically, as evidenced by the fact that
text/markdown was in there twice before this change. :^)
Also broke out tables of sufffixes and basenames we consider plaintext,
and sorted those alphabetically as well.
It makes far more sense to sort by the standard mime type strings,
rather than the ad-hoc variable names associated with each enumeration.
This way, the sort looks nicer, and also matches the corresponding
description enumerations in the file utility.
This enum used to store very precise state about the decoding process,
let's simplify that by only including two steps: HeaderDecoder and
BitmapDecoded.
https://www.haiku-os.org/images/bg-page.png has a size of 0 for
example.
Just ignoring the chunk instead of assuming that the image is sRGB
and has Perceptual rendering intent matches what libpng does
(cf `png_handle_sRGB()`), so let's do that too.
(All other chunk handlers are still strict about size.)
Max width shouldn't be tied to min width, commit d33b99d went too far
and made them the same when the table-root had a specified percentage
width.
Fixes#19940.
Now that we use the HTML image loading algorithm from spec, we can
implement complete correctly.
This (finally) fixes an issue where images were not loading on
https://twinings.co.uk/ :^)
When the intersection root is a Document, we use the viewport itself as
the root intersection rectangle. However, we should only use the size of
the viewport and strip away the current scroll offset.
This is important, as intersections are computed using viewport-relative
element rects, so we're already in a coordinate system where (0, 0) is
the top left of the scrolled viewport.
This fixes an issue where IntersectionObservers would fire at entirely
wrong scroll offsets. :^)
Cell::heap() and Cell::vm() needed to access member functions from
HeapBlock, and wanted to be inline, so they were moved to VM.h.
That approach will no longer work with VM.h not being included in every
file (starting from the next commit), so this commit fixes that circular
import issue by introducing secondary base classes to host the
references to Heap and VM, respectively.
Previously, we started parsing the ELF file again in a completely
different place, and without the partial mapping that we do while
validating.
Instead of doing manual parsing in two places, just capture the
requested stack size right after we validated it.
Since the underlying HTML::Window can change, caching property accesses
on WindowProxy is not as simple as remembering the shape. Let's disable
caching here for now. We can come back to it in the future when we have
no low-hanging fruit left. :^)
Fixes an assertion failure on https://twinings.co.uk/
Since we can't rely on shape identity (i.e its pointer address) for
unique shapes, give them a serial number that increments whenever a
mutation occurs.
Inline caches can then compare this serial number against what they
have seen before.
This dict contains some metadata in some files.
Newer files also contain XMP metadata, but it's recommended to
still include this dict as well, for compatibility with older readers.
And it's much less complex than XMP, so let's support it.
