If GetGlyphOutlineW(GGO_METRICS) fails to retreive the metrics for the
specified glyph it returns GDI_ERROR. Like ft, do not interpret this as a
fatal error but just mark the glyph as empty.
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=20255
Bug 20255 -- cairo_scaled_font_glyph_extents breaks with invalid glyph id
_font_map_release_face_lock_held() was being called unconditionally during
_cairo_ft_font_reset_static_data(). This presents two problems. The first
is that we call FT_Done_Face() on an object not owned by cairo, and the
second is that the bookkeeping is then incorrect which will trigger an
assert later.
Bug 21706 -- zombie ft_font_face / ft_unscaled_font mutual
referencing problems
[http://bugs.freedesktop.org/show_bug.cgi?id=21706]
There can be more than one zombie font_face belonging to an unscaled_font,
but only the first is destroyed. This leaks the client's FT_Face
(and associated font data) as release of the FT_Face depends on release
of the font_face.
(The reason why Firefox ends up with two different font_faces for one
unscaled_font is that load_flags for faces with artificial oblique have
FT_LOAD_NO_BITMAP set.
https://bugzilla.mozilla.org/show_bug.cgi?id=486974)
Also it's possible for _cairo_ft_font_face_create to pull out a zombie
font_face from the unscaled_font, which would crash
_cairo_ft_font_face_scaled_font_create, as that expects non-null
font_face->unscaled (if !font-face->pattern).
Truc Troung reported that the behaviour of
cairo_set_tolerance()/cairo_get_tolerance() was inconsistent with the
documentation, i.e. we failed to mention that the tolerance would be
restricted to the smalled fixed-point value.
Add a sentence to the documentation that describes the restriction without
mentioning what that is... Hopefully that is sufficient detail to
accommodate the reporter, without exposing internal implementation details.
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=20095
Bug 20095 - The cairo_set_tolerance() function behavior is inconsistency
with the spec
As pointed out by Truc Truong,
cairo_image_surface_create_from_png_stream() cannot return NULL and so the
documentation was incorrect.
Fixes http://bugs.freedesktop.org/show_bug.cgi?id=20075
Bug 20075 There is a misprint in the spec for
cairo_image_surface_create_from_png_stream() function
If a matrix was something like [0 .000001 0, .000001 0 0] the old code would
assume that xx and yy were greater than 0 and turn the nearly degenerate matrix
into an actual degenerate one. This caused things to blow up later on. Now we
check that our nearly rectangular matrices are not nearly degenerate, and let
the nearly degenerate ones fall through to the non-rectangular path.
Note: I'm not sure why NEARLY_ZERO(d) is fabs(d) < 1/65536 instead of some
other value. Hopefully, it's a useful definition.
This problem was found by a test case attached to:
https://bugzilla.mozilla.org/show_bug.cgi?id=467423
Otherwise this may leads to an invalid memory access to r.
Fixes: Bug 18588 - XCB backend fails with missing render.
https://bugs.freedesktop.org/show_bug.cgi?id=18588
Signed-off-by: Julien Danjou <julien@danjou.info>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
(cherry picked from commit 834f1d7b70)
Sascha Steinbiss reported a bug where the PDF backend was reading beyond
the end of the glyph array:
http://lists.cairographics.org/archives/cairo/2008-December/015976.html.
It transpires that in the early glyph culling in the gstate we were
not updating the clusters to skip culled glyphs.
Repeat should be handled using MOD instead of '%' so that negative numbers
are handled as expected. E.g. -1 mod 600 = 599, not 495 as the '%' operator
gives. This was causing https://bugzilla.mozilla.org/show_bug.cgi?id=466258
Patch from Robert O'Callahan
Peter Hercek reported, and provided a very useful test case for, a bug
that caused his applications to crash with Cairo detecting an
non-invertible pattern matrix and thus asserting the impossible happened.
Bisecting revealed that the bug first appeared with 3c18d95 and
disappeared with 0d0c6a1. Since neither of these explain the crash,
further investigation revealed a compiler bug (gcc 4.3.3 20081130,
earlier versions have different bugs!) that caused the matrix inversion
to be invalid iff _cairo_matrix_scalar_multiply() was inlined (i.e. -O0,
or an explicit noinline atttribute on that function prevented the bug, as
did -msse.) So we apply this workaround to hide the bug in the stable
series...
The matrix is quite often just a simple scale and translate (or even
identity!). For this class of matrix, we can skip the full adjoint
rearrangement and determinant calculation and just compute the inverse
directly.
(cherry picked from commit 0d0c6a199c)
test/text-glyph-range was crashing since we requested the meta_surface but
the glyph wrongly believed it already had the meta_surface but was
checking for a path instead.
Adrian Johnson discovered cases where we mistakenly compared the result
of unsigned arithmetic where we need signed quantities. Look for similar
cases in the users of cairo_rectangle_int_t.
_cairo_gstate_backend_to_user_rectangle() requires that its input
arguments are non-NULL and describe the input rectangle to be transformed.
However, we were passing through output parameters from the public API
which were allowed to be NULL. So we need to allocate temporary variables
in which to compute the output rectangle, but only copy them as required.
If the image was opaque with no alpha channel, we filled the output alpha
with 0. Typically, the destination surface for dithering is an RGB window,
so this bug went unnoticed. However, test/xlib-expose-event is an example
where we generate an intermediate alpha-only pixmap for use as a stencil
and this was failing as the mask was left completely transparent. The
simple solution is to ensure that for opaque images, the output alpha is
set to the maximum permissible value.
It's not fair to steal this name from the namespace of family names.
There are definitely cairo.ttf files that exist out there, and people
may already be using these, (or may use them in the future), with
cairo_select_font_face and a family name of "cairo".
In place of this, we'll want to come up with some other new, and
documented API for selecting the internal font face.
Carl spotted that 1db894 introduced an error into text_to_glyphs() such
that following an allocation error the code would attempt to thaw an
unfrozen glyph cache, leading to an attempt to unlock an unlocked mutex -
which causes a deadlock under win32.
Quartz fonts and user fonts use an indirect font face when creating a
scaled font for the toy font face. This means that they insert a scaled
font into the font map that has a different font face to the one that is
initially searched upon. The result is that when we try to create an
identical scaled font, we fail to find the existing scaled font and
attempt to insert a duplicate into the hash table - which triggers an
assert.
In order to avoid creating duplicate fonts, we add a new method to the
font backends that allows cairo_scaled_font_create() to peek at the
font_face that will be used to actually implement the scaled font
constructor - thus we are able to use the correct font_face as part of the
hash key.
After discussing the scaled font locking with Behdad, it transpired that it
is not sufficient for a font to be locked for the lifetime of a scaled glyph,
but that the scaled font's glyph cache must be frozen for the glyph'
lifetime. If the cache is not frozen, then there is a possibility that the
glyph may be evicted before the reference goes out of scope i.e. the glyph
becomes invalid whilst we are trying to use it.
Since the freezing of the cache is the stronger barrier, we remove the
locking/unlocking of the mutex from the backends and instead move the
mutex acquisition into the freeze/thaw routines. Then update the rule on
acquiring glyphs to enforce that the cache is frozen and review the usage
of freeze/thaw by all the backends to ensure that the cache is frozen for
the lifetime of the glyph.
Mention in the API docs that you can pass a NULL filename to
cairo_(pdf|ps|svg)_surface_create in order to construct a queryable
surface without generating any temporary files. Similarly when passing a
NULL write_func to cairo_pdf_surface_create_for_stream et al.
