[fpc-devel] Now sure why this raises Runtime Error 216

[Ozz Nixon]

Ok, I'll check it out. Thanks guys,  did not realize it was a pointer, too
many years writing scripts instead of code. Thanks!!

On Thu, Jan 6, 2022, 11:51 PM Michael Van Canneyt <michael at freepascal.org>
wrote:

>
>
> On Thu, 6 Jan 2022, Ozz Nixon via fpc-devel wrote:
>
> > Procedure Make_Language_File(
> >   Description,MenuPath,TextPath,QuestPath:String;
> >   Enabled:Boolean;SecurityLevel:Byte;Flags:Longint);
> > Var
> >   FileSize:Longint;
> >
> > Begin
> >   Writeln('Language_File empty size is ',SizeOf(L));
> >   FileSize:=0;
> >   Description:=Description+#0;
> >   Inc(FileSize,Length(Description));
> >   MenuPath:=MenuPath+#0;
> >   Inc(FileSize,Length(MenuPath));
> >   TextPath:=TextPath+#0;
> >   Inc(FileSize,Length(TextPath));
> >   QuestPath:=QuestPath+#0;
> >   Inc(FileSize,Length(QuestPath));
> >   SetLength(L.Description,Length(Description));
> >   SetLength(L.MenuPath,Length(MenuPath));
> >   SetLength(L.TextPath,Length(TextPath));
> >   SetLength(L.QuestPath,Length(QuestPath));
> >   Move(Description[1],L.Description,Length(Description));
>
> This code is wrong. That must be
>
> Move(Description[1],L.Description[0],Length(Description));
>
> >   Move(MenuPath[1],L.MenuPath,Length(MenuPath));
>
> Same here.
> Move(MenuPath[1],L.MenuPath[0],Length(MenuPath));
>
> >   Move(TextPath[1],L.TextPath,Length(TextPath));
>
> Same here
> Move(TextPath[1],L.TextPath[0],Length(TextPath));
>
> >   Move(QuestPath[1],L.QuestPath,Length(QuestPath));
>
> Same here.
> Move(QuestPath[1],L.QuestPath[0],Length(QuestPath));
>
> These fields are dynamic arrays, in essence pointers to a memory block.
>
> Your code writes to the memory area for pointer, not to the memory area
> the pointer points to.
>
> Michael.
>
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