1 files changed, 23 insertions, 10 deletions

diff --git a/libbb/arith.c b/libbb/arith.c
index c7a3cf98b..04c45ec3d 100644
--- a/libbb/arith.c
+++ b/libbb/arith.c
@@ -119,20 +119,26 @@ static short arith_apply(operator op, long *numstack, long **numstackptr)
                 NUMPTR[-1] = (NUMPTR[-1] <= *NUMPTR);
         else if (op == TOK_MUL)
                 NUMPTR[-1] *= *NUMPTR;
-        else if (op == TOK_DIV)
+        else if (op == TOK_DIV) {
+                if(*NUMPTR==0)
+                        return -2;
                 NUMPTR[-1] /= *NUMPTR;
-        else if (op == TOK_REM)
+                }
+        else if (op == TOK_REM) {
+                if(*NUMPTR==0)
+                        return -2;
                 NUMPTR[-1] %= *NUMPTR;
+                }
         else if (op == TOK_ADD)
                 NUMPTR[-1] += *NUMPTR;
         else if (op == TOK_SUB)
                 NUMPTR[-1] -= *NUMPTR;
         }
         return 0;
-err: return(1);
+err: return(-1);
 }
 
-extern long arith (const char *startbuf)
+extern long arith (const char *startbuf, int *errcode)
 {
         register char arithval;
         const char *expr = startbuf;
@@ -142,8 +148,9 @@ extern long arith (const char *startbuf)
         unsigned char prec;
 
         long *numstack, *numstackptr;
-
         operator *stack = alloca(datasizes * sizeof(operator)), *stackptr = stack;
+
+        *errcode = 0;
         numstack = alloca((datasizes/2+1)*sizeof(long)), numstackptr = numstack;
 
         while ((arithval = *expr)) {
@@ -163,7 +170,8 @@ extern long arith (const char *startbuf)
                                 op = *--stackptr;
                                 if (op == TOK_LPAREN)
                                         goto prologue;
-                                if(ARITH_APPLY(op)) goto err;
+                                *errcode = ARITH_APPLY(op);
+                                if(*errcode) return *errcode;
                         }
                         goto err; /* Mismatched parens */
                 } if (arithval == '|') {
@@ -231,17 +239,22 @@ extern long arith (const char *startbuf)
 
                 prec = PREC(op);
                 if (prec != UNARYPREC)
-                        while (stackptr != stack && PREC(stackptr[-1]) >= prec)
-                                if(ARITH_APPLY(*--stackptr)) goto err;
+                        while (stackptr != stack && PREC(stackptr[-1]) >= prec) {
+                                *errcode = ARITH_APPLY(*--stackptr);
+                                if(*errcode) return *errcode;
+                        }
                 *stackptr++ = op;
                 lasttok = op;
 prologue: ++expr;
         } /* yay */
 
-        while (stackptr != stack)
-                if(ARITH_APPLY(*--stackptr)) goto err;
+        while (stackptr != stack) {
+                *errcode = ARITH_APPLY(*--stackptr);
+                if(*errcode) return *errcode;
+        }
         if (numstackptr != numstack+1) {
 err: 
+            *errcode = -1;
             return -1;
          /* NOTREACHED */
         }