[Chicken-janitors] #459: -picky shouldn't warn when other path also returns an undefined value?

[Chicken Trac]

#459: -picky shouldn't warn when other path also returns an undefined value?
----------------------+-----------------------------------------------------
 Reporter:  alanpost  |       Owner:       
     Type:  defect    |      Status:  new  
 Priority:  minor     |   Milestone:  4.7.0
Component:  compiler  |     Version:  4.6.x
 Keywords:            |  
----------------------+-----------------------------------------------------
 I'm not sure this issue can be fixed, but here it goes:

 The following code:

 {{{
 (define (foo)
   (if condition (for-each (lambda x x) '(0 1 2))))
 }}}

 when compiled with '-picky', gives the following warning:

 {{{
 Warning: in toplevel procedure `foo':
   conditional in tail-position has branch with undefined result:

 (if condition (let (... ...) (let ... ...)) (##core#undefined))
 }}}

 However, the other branch *also* returns an undefined result, making this
 particular warning a no-op in this case.

 I would expect to not see this error when both branches return the same
 result.

 Is this condition detectable?

-- 
Ticket URL: <http://bugs.call-cc.org/ticket/459>
Chicken Scheme <http://www.call-with-current-continuation.org/>
Chicken Scheme is a compiler for the Scheme programming language.