From 01ac83b971fd13ed0efc8b5de176c596b59f5c58 Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Thu, 8 Jan 1987 14:10:02 +0000
Subject: [PATCH] fix to prevent loop resulting in stack overflow

---
 mach/proto/ncg/reg.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/mach/proto/ncg/reg.c b/mach/proto/ncg/reg.c
index fc3546c6c..9f645fbec 100644
--- a/mach/proto/ncg/reg.c
+++ b/mach/proto/ncg/reg.c
@@ -71,6 +71,12 @@ getrefcount(regno) {
 
 erasereg(regno) {
 	register struct reginfo *rp;
+	register int i;
+
+	rp = &machregs[regno];
+	rp->r_contents.t_token = 0;
+	for (i=0;i<TOKENSIZE;i++)
+		rp->r_contents.t_att[i].aw = 0;
 
 #if MAXMEMBERS==0
 	awayreg(regno);
@@ -86,11 +92,6 @@ awayreg(regno) {
 	register tkdef_p tdp;
 	register i;
 
-	rp = &machregs[regno];
-	rp->r_contents.t_token = 0;
-	for (i=0;i<TOKENSIZE;i++)
-		rp->r_contents.t_att[i].aw = 0;
-
 	/* Now erase recursively all registers containing
 	 * something using this one
 	 */
@@ -98,7 +99,7 @@ awayreg(regno) {
 		if (rp->r_contents.t_token == -1) {
 			if (rp->r_contents.t_att[0].ar == regno)
 				erasereg(rp-machregs);
-		} else {
+		} else if (rp->r_contents.t_token > 0) {
 			tdp= & tokens[rp->r_contents.t_token];
 			for (i=0;i<TOKENSIZE;i++)
 				if (tdp->t_type[i] == EV_REG && 
-- 
2.34.1