rand/dsarand.c: Return the old number of passes from `DSARAND_PASSES'.

Also, don't update if the input operand is zero.

diff --git a/rand/dsarand.c b/rand/dsarand.c
index 70ffaf8..a4328aa 100644 (file)
--- a/rand/dsarand.c
+++ b/rand/dsarand.c
@@ -282,9 +282,11 @@ static int gmisc(grand *r, unsigned op, ...)
       grand *rr = va_arg(ap, grand *);
       rr->ops->fill(rr, g->d.p, g->d.sz);
     } break;
-    case DSARAND_PASSES:
-      g->d.passes = va_arg(ap, unsigned);
-      break;
+    case DSARAND_PASSES: {
+      unsigned n = va_arg(ap, unsigned);
+      rc = g->d.passes;
+      if (n > 0) g->d.passes = n;
+    } break;
     case DSARAND_SEEDSZ:
       rc = g->d.sz;
       break;