When an internal-definition context is used with `local-expand`, the
any binding added to the context affect expansion, but the binding do
not appear in the expansion. As a result, Check Syntax was unable to
draw an arrow from the `s` use to its binding in
(class object%
(define-struct s ())
s)
The general solution is to add the internal-definition context's
bindings to the expansion as a 'disappeared-bindings property. The new
`internal-definitionc-context-track` function does that using a new
`internal-definition-context-binding-identifier` primitive.
Mishandling of the `require`-binding table could cause
`racket/private/pre-base` to export `andmap` as syntax, for example,
instead of as a variable. The syntax-versus-variable distinction
doesn't usually matter, but it affects the order of exports in
bytecode form.
Even though `dynamic-require` might lead to loading source, the
path into the compiler for that source will force compile-time code
as needed.
One benefit of ths change is that `racket -l pict3d` takes about half
as long, because `racket/gui` includes a `dynamic-require` to load a
platform-specific back-end, while `pict3d` can pull in a lot of
compile-time code to cooperate with Typed Racket.
Getting NULL from CTFontCollectionCreateMatchingFontDescriptors()
might indicate a font installation problem; I'm not sure. In any case,
checking for NULL avoids a crash on at least one installation.
This bug is already fixed in the Cairo source repo, so we
can discard the patch on the next Cairo upgrade.
It's not clear which platforms are affected. On OS X, at least,
writing to a global constant can cause a crash.
Thanks to Spencer for making a small example that triggers the bug
(added to the "draw-test" package).
The CTFontCreatePathForGlyph() function can return NULL when
the glyph exists but has an empty path. Instead of treating that
as failure, which causes Cairo to generate a bitmap version of
the glyph, check that the glyph is mapped for bounding boxes,
and treat a NULL path as an empty path in that case.
