Potential Bug: Stack is cleared after Daedalus function call

[Luis Michaelis]

There might be a problem with this code, if a Daedalus function is called from within an external, because the entire stack (including previous function's stacks) might be cleared:

ZenKit/include/zenkit/DaedalusVm.hh

Lines 153 to 170 in 7121a33

 unsafe_call(sym); 
  
 if constexpr (std::is_same_v<R, IgnoreReturnValue>) { 
 	// clear the stack 
 	_m_stack_ptr = 0; 
  
 	return {}; 
 } else if constexpr (!std::is_same_v<R, void>) { 
 	auto ret = pop_call_return_value<R>(); 
  
 	// clear the stack 
 	_m_stack_ptr = 0; 
  
 	return ret; 
 } else { 
 	// clear the stack 
 	_m_stack_ptr = 0; 
 } 

Instead, we should clear the stack up to the previous call frame (taking into account return values). There should also be an unsafe function to trigger this behaviour from C and wrappers.

[Luis Michaelis]

Fixed in f53a955 by properly counting stack size.