Re: [PATCH v2 0/1] MR4418: cmd: Delay variable substitution until after the if clause is parsed.

[Alex Henrie (＠alexhenrie)]

On Wed Nov 22 18:02:56 2023 +0000, eric pouech wrote:
> my point is more about the way to implement the fix rather if the
> propose fix passes the tests
> cmd as of today is barely maintanable because of small adjustements here
> and there, added over the years
> your proposal is such a small adjustment by changing behavior of some
> helper functions, depending on context, whereas IMO the cause of the
> issue lies elsewhere

I can appreciate the fact that Wine's cmd.exe implementation is kind of ugly. Nonetheless, in my opinion it's not reasonable to require a near-total rewrite of cmd.exe in order to fix this bug. `IF` is very special in cmd, and would still have to be treated specially even if cmd.exe were completely rewritten. The correct order of operations is to expand % variables, then parse the operands, then expand ! variables. Whether we have functions like handleExpansion, evaluate_if_condition, and do_delayed_expansion for those steps or whether we have a tokenizer that does it all, there has to be code to define the order, and that code would be similar in either case.