(waitpid -1 #f) now returns #f if no child has died yet.

scheme/ikarus.posix.ss

@@ -122,7 +122,7 @@
               (signal-code->signal-name 
                 (wstatus-received-signal r)))
             r]
-           [want-error?
+           [(and want-error? (not (eqv? r 0)))
             (error who (strerror r) pid)]
            [else #f]))]))
 

scheme/last-revision

@@ -1 +1 @@
-1515
+1516

src/ikarus-process.c

@@ -193,11 +193,11 @@ ikrt_waitpid(ikptr rvec, ikptr pid, ikptr block /*, ikpcb* pcb */){
       ref(rvec, off_record_data+2*wordsize) = 
         ik_signal_num_to_code(WTERMSIG(status));
     }
-  }else if(r == 0){  /* would have blocked */
-    ;  /* let rvec return as all #f's */
-  }else {
+    return rvec;
+  } else if(r == 0){  /* would have blocked */
+    return fix(0);
+  } else {
     return ik_errno_to_code();
   }
-  return rvec;
 }