From 2a00e1d4c02e1090b5d4f8e8af62e457eaba7ecb Mon Sep 17 00:00:00 2001
From: Ralph Campbell <ralph@ucbvax.Berkeley.EDU>
Date: Sat, 16 May 1992 18:01:52 -0800
Subject: [PATCH] check for divide by zero.

SCCS-vsn: bin/expr/expr.y 5.2
---
 usr/src/bin/expr/expr.y | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/usr/src/bin/expr/expr.y b/usr/src/bin/expr/expr.y
index f9af96c727..2766cd7c82 100644
--- a/usr/src/bin/expr/expr.y
+++ b/usr/src/bin/expr/expr.y
@@ -66,7 +66,7 @@ char copyright[] =
 #endif /* not lint */
 
 #ifndef lint
-static char sccsid[] = "@(#)expr.y	5.1 (Berkeley) %G%";
+static char sccsid[] = "@(#)expr.y	5.2 (Berkeley) %G%";
 #endif /* not lint */
 
 #include <stdio.h>
@@ -145,8 +145,18 @@ char *arith(op, r1, r2) char *r1, *r2; {
 	case ADD: i1 = i1 + i2; break;
 	case SUBT: i1 = i1 - i2; break;
 	case MULT: i1 = i1 * i2; break;
-	case DIV: i1 = i1 / i2; break;
-	case REM: i1 = i1 % i2; break;
+	case DIV:
+		if (i2 != 0)
+			i1 = i1 / i2;
+		else
+			yyerror("Divide by zero");
+		break;
+	case REM:
+		if (i2 != 0)
+			i1 = i1 % i2;
+		else
+			yyerror("Remainder by zero");
+		break;
 	}
 	rv = malloc(16);
 	(void)sprintf(rv, "%ld", i1);
-- 
2.20.1