Please don't close it.<br/>
If someone doesn't understand something (or doesn't want spent more time to go deeper), this is not a reason to close the ticket.<br/>
Regarding the examples - the ticket contains enough of them to illustrate the wrong behavior of <code>Tcl_ObjSetVar2</code> and co in the error case.

Basically since <code>Tcl_ObjSetVar2</code> doesn't create an object and doesn't realy own an object in case of error (because it doesn't in common sense), <b>it should not decrease a reference in error case</b> at all, even less on certain conditions only (depending on the reference count of object, how it does right now) - this is dirty workaround and not a solution. Especially undocumented, see [https://www.tcl-lang.org/man/tcl/TclLib/SetVar.htm|SetVar.htm]. 
However the only way to fix it properly - use a new flag <code>TCL_OWN_OBJREF</code>, like I did it.

Additionally I'd like to note that after the fix [bc5e7bdafc922baf] (and later with a new flag <code>TCL_OWN_OBJREF</code> I implemented) I never saw this bug anymore (neither the reference error, nor the leak).