Don't crash when marking arguments object of native context

JSC assumes that the callee is always valid, since JSC::Arguments
is used for JS frames, which must have a callee.
But we use JSC::Arguments for arguments object of
pushContext()-created contexts, and then there is no callee.
But the callee member can't be null, so now we put a fake callee
there and make sure it doesn't bleed up to the public API.

Alternative solution: Add "if (d->callee)" to
JSC::Arguments::markChildren(), then no other changes would be
needed. But we don't want to patch JSC any more.

Non-solution: Subclass JSC::Arguments and reimplement
markChildren() to temporarily set a dummy callee during marking.
Can't be done, as JSC::Arguments::d is private (again, we don't
want to patch JSC).

Task-number: QTBUG-17788
Reviewed-by: Olivier Goffart

0 files changed, 0 insertions, 0 deletions