[src/trunk]: src/usr.bin/jot Generate format after setting the prec value

[kamil <kamil%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/140abc3ef3a6
branches:  trunk
changeset: 934568:140abc3ef3a6
user:      kamil <kamil%NetBSD.org@localhost>
date:      Sun Jun 14 01:26:46 2020 +0000

description:
Generate format after setting the prec value

Otherwise we end up with setting invalid printf format: "%.-1f" (from
"if (snprintf(p, sz, "%%.%df", prec) >= (int)sz)") for prec equal to -1,
which is not canonical (rejected by gcc and clang when used explicitly).

Detected by ASan (MKSANITIZER) for "jot 8".

diffstat:

 usr.bin/jot/jot.c |  7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diffs (32 lines):

diff -r c96ed3b57967 -r 140abc3ef3a6 usr.bin/jot/jot.c
--- a/usr.bin/jot/jot.c Sun Jun 14 00:30:20 2020 +0000
+++ b/usr.bin/jot/jot.c Sun Jun 14 01:26:46 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: jot.c,v 1.27 2019/02/03 03:19:29 mrg Exp $     */
+/*     $NetBSD: jot.c,v 1.28 2020/06/14 01:26:46 kamil Exp $   */
 
 /*-
  * Copyright (c) 1993
@@ -39,7 +39,7 @@
 #if 0
 static char sccsid[] = "@(#)jot.c      8.1 (Berkeley) 6/6/93";
 #endif
-__RCSID("$NetBSD: jot.c,v 1.27 2019/02/03 03:19:29 mrg Exp $");
+__RCSID("$NetBSD: jot.c,v 1.28 2020/06/14 01:26:46 kamil Exp $");
 #endif /* not lint */
 
 /*
@@ -226,11 +226,12 @@
                errx(EXIT_FAILURE,
                    "Too many arguments.  What do you mean by %s?", argv[4]);
        }
-       getformat();
 
        if (prec == -1)
                prec = 0;
 
+       getformat();
+
        if (randomize) {
                /* 'step' is the seed here, use pseudo-random default */
                if (!(have & STEP))