QJsonValue: fix use-after-free in assignment operator

The assignment operator of a String QJsonValue that holds
the only remaining reference to the QString::Data block
was freeing the block before obtaining its own reference,
leading to a use-after-free in the case where *this was
passed as 'other' (self-assignment).

Fixed by reformulating the assignment operator in terms
of the copy ctor, using the copy-swap idiom, with the
twist that QJsonValue doesn't, yet, have a swap member
function, so we use three per-member qSwap()s.

Change-Id: I3c5ccc4d9f32c7593af3fc6a0edbf12b7feb1391
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>

0 files changed, 0 insertions, 0 deletions