From 71ca9ffa6d65aca48807025208f8f9bad20e073a Mon Sep 17 00:00:00 2001
From: Chris Hanson <org/chris-hanson/cph>
Date: Wed, 29 Jul 1987 02:16:52 +0000
Subject: [PATCH] When walking predicate nodes, must be able to handle case
 where either the consequent or alternative is nonexistent.  This is because
 we must walk over incomplete graphs when generating code for operands.

---
 v7/src/compiler/rtlgen/rtlgen.scm | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/v7/src/compiler/rtlgen/rtlgen.scm b/v7/src/compiler/rtlgen/rtlgen.scm
index a4744a34a..8a8731605 100644
--- a/v7/src/compiler/rtlgen/rtlgen.scm
+++ b/v7/src/compiler/rtlgen/rtlgen.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlgen/rtlgen.scm,v 1.15 1987/05/21 15:05:03 cph Exp $
+$Header: /Users/cph/tmp/foo/mit-scheme/mit-scheme/v7/src/compiler/rtlgen/rtlgen.scm,v 1.16 1987/07/29 02:16:52 cph Exp $
 
 Copyright (c) 1987 Massachusetts Institute of Technology
 
@@ -125,8 +125,10 @@ MIT in each case. |#
   (lambda (node subproblem?)
     (pcfg*scfg->scfg!
      (generator node)
-     (generate/node (pnode-consequent node) subproblem?)
-     (generate/node (pnode-alternative node) subproblem?))))
+     (and (pnode-consequent node)
+	  (generate/node (pnode-consequent node) subproblem?))
+     (and (pnode-alternative node)
+	  (generate/node (pnode-alternative node) subproblem?)))))
 
 (define-integrable (node-rtl-result node)
   (node-property-get node tag/node-rtl-result))
-- 
2.25.1