#2 NULL pointer dereference in mgame.cpp

[Evil Clone]

Once a melee game has been completed, if you press a
key a NULL pointer dereference occurs in
Ship::calculate() as follows:

if (control)
target = control->target;

// communication code
if ( (nextkeys & keyflag::communicate) &&
(target->exists ()) && (target->isShip()))
{
Ship * s = (Ship*)target;
if( s->ext_ai != NULL )
s->ext_ai->Dialog(this);
}

control is non-NULL, but control->target is NULL when
there are no targets left. Thus, if a key is pressed
there is a NULL pointer dereference here.

Correction simply checks for target == NULL

if ( target != NULL && (nextkeys &
keyflag::communicate) && (target->exists ()) &&
(target->isShip()))
{
Ship * s = (Ship*)target;
if( s->ext_ai != NULL )
s->ext_ai->Dialog(this);
}

[Evil Clone]

Patch as described above, also includes Rogue Pointer patch from #955821