When exactly four bytes remain, mvelib will attempt to compute a
past-the-end pointer. Some handlers will dereference this pointer
without rechecking the length. Adjust the header check to require a
non-empty body.
Reported-by: jwrdegoede <https://github.com/dxx-rebirth/dxx-rebirth/issues/413>
The movie code assumes that when the topmost window is closed, that
window must have been the movie window, and that the movie data can now
be freed. However, if the movie is paused, a new topmost window is
created to tell the user that the movie is paused. When that topmost
pause window is deleted, the movie code frees the movie data, even
though the movie is not done. Corruption ensues, ultimately leading to
a crash.
Reported-by: Jayman2000 <https://github.com/dxx-rebirth/dxx-rebirth/issues/410>
For each link given as http://, verify that the site is accessible over
https:// and, if so, switch to it. These domains were converted:
* llvm.org
* clang.llvm.org
* en.cppreference.com
* www.dxx-rebirth.com
* www.libsdl.org
* www.scons.org
