bc: make division operation interruptible

function                                             old     new   delta
bc_num_d                                             564     584     +20
bc_num_r                                             230     245     +15
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(add/remove: 0/0 grow/shrink: 2/0 up/down: 35/0)               Total: 35 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/miscutils/bc.c b/miscutils/bc.c
index 6dc79118a6115c22f3e33dc98aa44cfdedabf61e..073a113fb71db2490bc292c2c2f7b27773fb5a57 100644 (file)
--- a/miscutils/bc.c
+++ b/miscutils/bc.c
@@ -1840,12 +1840,19 @@ static BcStatus bc_num_d(BcNum *a, BcNum *b, BcNum *restrict c, size_t scale)
                for (q = 0; (!s && n[len] != 0) || bc_num_compare(n, p, len) >= 0; ++q)
                        bc_num_subArrays(n, p, len);
                c->num[i] = q;
+               // a=2^100000
+               // scale=40000
+               // 1/a <- without check below, this will not be interruptible
+               if (G_interrupt) {
+                       s = BC_STATUS_FAILURE;
+                       break;
+               }
        }
 
        bc_num_retireMul(c, scale, a->neg, b->neg);
        bc_num_free(&cp);
 
-       return BC_STATUS_SUCCESS; // can't make void, see bc_num_binary()
+       return s;
 }
 
 static BcStatus bc_num_r(BcNum *a, BcNum *b, BcNum *restrict c,
@@ -1864,7 +1871,8 @@ static BcStatus bc_num_r(BcNum *a, BcNum *b, BcNum *restrict c,
        }
 
        bc_num_init(&temp, d->cap);
-       bc_num_d(a, b, c, scale);
+       s = bc_num_d(a, b, c, scale);
+       if (s) goto err;
 
        if (scale != 0) scale = ts;