id	summary	reporter	owner	description	type	status	milestone	component	version	severity	resolution	keywords	cc
3930	DllStructs created in one scope gets dropped if chained with a function that returns a re-structured-by-pointer version of it	AutoXenon		"Original thread: https://www.autoitscript.com/forum/topic/209074-dllstructs-created-in-one-scope-gets-dropped-if-chained-with-a-function-that-returns-a-re-structured-by-pointer-version-of-it


{{{
GUICreate('')
Local $unreliable_data, $reliable_data, $intermediate_ref, $labelunreliable = GUICtrlCreateLabel('',0,0,400,25), $labelreliable = GUICtrlCreateLabel('',0,30,400,25)
GUISetState()
HotKeySet('{esc}',quit)
While True
      $unreliable_data = parseStruct(createStruct())  ; struct technically goes out of scope, this saves a ""slave struct"" but the master struct gets dropped when it goes out of parseStruct's scope
      $intermediate_ref = createStruct()              ; struct scope gets transferred, this is a ""master struct""
      $reliable_data = parseStruct($intermediate_ref) ; a ""slave struct"" of a master struct that is scoped here
      Sleep(100)                                      ; wait some time for garbage to get written into the freed memory 
      GUICtrlSetData($labelunreliable,DllStructGetData($unreliable_data,'msg'))
      GUICtrlSetData($labelreliable,DllStructGetData($reliable_data,'msg'))
WEnd


Func createStruct()
     Local $struct = DllStructCreate('char[16]')
     DllStructSetData($struct,1,'hello world')
     Return $struct
EndFunc

Func parseStruct($struct)
     Return DllStructCreate('char msg[16]',DllStructGetPtr($struct))
EndFunc

Func quit()
     Exit
EndFunc
}}}


The question is, ''should'' create-by-pointer structs count as valid references? I can imagine that if it is change to be so, it might cause headaches with ad-hoc throwaway ""lens"" structs unintentionally preventing the memory from being freed if the programmer is expecting it to ''not'' count as valid references. I guess it's up to you to decide on which tradeoff to pick."	Bug	closed		AutoIt	3.3.16.1	None	No Bug