From: Mark Wooding <mdw@distorted.org.uk>
Date: Fri, 27 Feb 2015 14:44:45 +0000 (+0000)
Subject: progs/factorial.c: Reject negative inputs.
X-Git-Tag: 2.2.0~15
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~mdw/git/catacomb/commitdiff_plain/1f14c0c645ce384406e405000375c7fb9e60cc9e?ds=inline;hp=--cc

progs/factorial.c: Reject negative inputs.

Otherwise they get reduced mod 2^large, and the program takes forever.
It's not like we'd get a better answer by using the full-on Gamma
function, so just report an error.
---

1f14c0c645ce384406e405000375c7fb9e60cc9e
diff --git a/progs/factorial.c b/progs/factorial.c
index a46debd1..975c698c 100644
--- a/progs/factorial.c
+++ b/progs/factorial.c
@@ -135,7 +135,7 @@ int main(int argc, char *argv[])
   xx = mp_readstring(MP_NEW, argv[optind], &p, 0);
   while (isspace((unsigned char)*p))
     p++;
-  if (!xx || *p || MP_CMP(xx, >, ulmax))
+  if (!xx || *p || MP_CMP(xx, <, MP_ZERO) || MP_CMP(xx, >, ulmax))
     die(EXIT_FAILURE, "bad integer `%s'", argv[optind]);
   x = mp_toulong(xx);
   mp_drop(xx);