Previously, forward references were required to use named destinations.
This patch is based on the patch in #336 by Guillaume Ayoub <guillaume.ayoub@kozea.fr>
that converted all links to indirect objects written at the end of the document.
I have reworked the patch so that only forward references to future page numbers are
written as indirect objects. Backward references and named destinations remain as they
are. This is to minimize the number of objects written to the PDF file.
Fixes#336
cairo-pdf was silently ignoring write errors in
_cairo_pdf_surface_finish(). Any write errors that happened here ended
up setting a "status" variable, but the value in this variable was then
unused.
This commit fixes this bug by passing this error on to the caller.
Additionally, this also adds a test case for this behaviour based on
writing to /dev/full. This file is non-standard and thus the test first
checks that this file exists and is writable before trying to write to
it.
This bug was found based on a report from Knut Petersen [0].
[0]: https://lists.cairographics.org/archives/cairo/2021-July/029281.html
Signed-off-by: Uli Schlachter <psychon@znc.in>
A hash value is encoded in base 26 with upper case letters for font
names.
Commit ed984146 replaced "numerator = abs (hash);" with "numerator =
hash;" in this code, because hash has type uint32_t and the compiler
warned about taking the absolute value of an unsigned value. However,
abs() is actually defined to take an int argument. Thus, there was some
implicit cast.
Since numerator has type long, i.e. is signed, it is now actually
possible to get an overflow in the implicit cast and then have a
negative number. The following code is not prepared for this and
produces non-letters when encoding the hash.
This commit fixes that problem by not using ldiv() and instead using /
and % to directly compute the needed values. This gets rid of the need
to convert to type long. Since now everything works with uint32_t, there
is no more chance for negative numbers messing things up.
Fixes: https://gitlab.freedesktop.org/cairo/cairo/-/issues/449
Signed-off-by: Uli Schlachter <psychon@znc.in>
The expression &image_surface->base basically just casts the
cairo_image_surface_t* to cairo_surface_t*. However, technically it is a
NULL pointer dereference and UndefinedBehaviorSanitizer flags it as
such:
runtime error: member access within null pointer of type 'cairo_image_surface_t' (aka 'struct _cairo_image_surface')
This commit fixes this by adding a NULL check.
Signed-off-by: Uli Schlachter <psychon@znc.in>
From further testing and investigation it appears that many PDF viewers
already have a workaround to invert Adobe CMYK JPEGs, so our generated
PDFs display incorrectly with those viewers due to double-inversion.
Further investigation will be needed to find a better solution that
doesn't cause regression for some PDF viewers; perhaps PDF viewers that
lack this inversion workaround should be changed to include it. For now
we'll drop the patch to avoid shipping the regression in 1.16.0.
This reverts commit b207a932a2.
Reference: https://bugs.freedesktop.org/show_bug.cgi?id=97612
Fixes: https://gitlab.freedesktop.org/cairo/cairo/issues/156
Patch 37a22669 improved performance by using bounding box extents.
However, the code appears to be incorrect. If extents is non-NULL it
copies its contents to group->extents, otherwise it sets group->extents
to sensible defaults, but then goes ahead and tries to copy the
undefined contents. This second copy is unnecessary if extents is
non-NULL and will cause a crash if it is NULL.
Drop the extra copy, guessing it's just a typo.
Coverity ID: #1159559
Signed-off-by: Bryce Harrington <bryce@bryceharrington.org>
Reviewed-By: Uli Schlachter <psychon@znc.in>
_cairo_malloc(0) always returns NULL, but has not been used
consistently. This patch replaces many calls to malloc() with
_cairo_malloc().
Fixes: fdo# 101547
CVE: CVE-2017-9814 Heap buffer overflow at cairo-truetype-subset.c:1299
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
- each annotation was emitted on every page instead of just the page
that contains the annotation
- the document structure did not correctly link to annotation objects
- fix some annotation related memory leaks
- Restructure the emit_surface code so that mime types are checked first.
- Add a test parameter to emit_surface to test if the surface will be emitted
as an image or recording instead checking the surface type as the attached
mime may override this.
- Mark surface as not clear when mime is attached to avoid optimizing away
"clear" surfaces that have mime attached.
- Include entire surface in analysis if mime attached (also fixes bug with
calculating the extents CONTENT_COLOR surfaces)
PDF XObjects need to specify the bounding box. Emit unbounded surfaces
when finishing as at this point the extents of all uses of the
unbounded surface are known.
Previously it was assumed the mime image size is the same as the cairo
image surface size. When using the 1 bpp formats (CCITT, JBIG2),
creating a cairo image of the same size will have very large memory
requirements and in some case may exceed the pixman image size
limits. In these cases it is useful to allow the mime image to have a
different resolution to the cairo image and in the PDF/PS output scale
the mime image to be the same physical size as the cairo image.
In PDF, this is easy as all PDF images are scaled to 1x1 unit and the
CTM is used to scale the image to the required size. The PS surface
has been changed to also scale images to 1x1 and use the CTM to get
the required size.
This completes the full set of PDF/PS image filters allowing image
data to be passed though without decompressing then recompresssing in
a less efficient format.
The difficulty with CCITT_FAX is it needs some decoding parameters
that are not stored inside the image data. This is achieved by using
an additional mime type CCITT_FAX_PARAMS that contains the params in
key=value format.
Converting the link position from cairo to pdf coordinates requires
the page height. Since the link may point to a different page, build
an array of the height of each page and use the target page height for
the conversion.
Don't default to a [0,0] position if "pos" is not specified. PDF
allows a null destination position to be specified which means don't
change the position if the page is already displayed or show top left
if switching to a different page. This is more useful default
particularly for external files where the coordinates (which must be
in PDF coordinates as we don't know the page height) of the top left
corner may not be known.
Adobe PhotoShop generates CMYK JPEG files with inverted CMYK. When a
JPEG file with this format is included in a PDF file, a `/Decode`
array must be included to convert to "normal" CMYK.
These JPEG files can be detected via the presence of the APP14 "Adobe"
marker. However, PDF viewers are not required to detect and handle
this private marker, so it must be detected and handled (by adding a
`/Decode`) by the PDF generator.
Signed-Off-By: Peter TB Brett <peter.brett@livecode.com>
When an unbounded recording surface is used multiple times with
different extents for each operation we need the XObject containing
the recording surface to have the same origin for each operation. This
is not possible when the recording surface is converted to PDF
coordinates because each operation has different extents resulting in
a different origin when the Y-axis is flipped (since the flip matrix
depends on the recording surface height which for unbounded surfaces
depends on the extents of the operation that paints the recording
surface).
Switching to cairo coordinates by emitting a Y-axis flip matrix as the
first object of each page allows the recording surface to be emitted
in cairo coordinates. This results in the same origin for all
operations using the recording surface XObject.
since the PS Document Structing Conventions impose a 255 character
line limit. PDF does not require wrapping.
pdf-operators is designed to emit the same output for PS and PDF.
Unfortunately some PDF interpreters don't like strings split with
'\\\n' and some PS interpreters don't like strings split with ')('.
So we are forced to make pdf-operators handling string wrapping
differently for PDF and PS.
Bug 85662
Sometimes as a result of rounding errors in matrix transformations the
matrices in ps/pdf output look like:
0.000000000000000061 1 1 -0.000000000000000061 0 842 cm
This patch rounds to zero matrix elements that are very small compared to
other elements in the same matrix.
Since PDF stores the alpha component of images in a separate stream
which can have a different resolution and encoding to the color
components we can optimize the case where the source and mask are both images.
If the source and mask are both images with the same extents and the
source is opaque, combine the images into a single PDF image (ie the
source is written the the image stream and the mask is written to the
smask stream).
JBIG2 images may have shared global data that is stored in a separate
stream in PDF. The CAIRO_MIME_TYPE_JBIG2 mime type is for the JBIG2
data for each image. All images that use global data must also set
CAIRO_MIME_TYPE_JBIG2_GLOBAL_ID to a unique identifier. One of the
images must also set CAIRO_MIME_TYPE_JBIG2_GLOBAL to the global
data. The global data will be shared by all JBIG2 images with the same
CAIRO_MIME_TYPE_JBIG2_GLOBAL_ID.
