here's a patch that fixes this problem
$ printf "<%3s><%3b>"
< ><>
---
xoxo iza
From c5ffd55ffa9224dd7919a4d09b27a11308d2152e Mon Sep 17 00:00:00 2001
From: izabera <izaber...@gmail.com>
Date: Sat, 24 Sep 2016 02:01:16 +0200
Subject: [PATCH] fix printf %b without an argument
old behavior:
$ printf "<%3s><%3b>"
< ><>
removed bogus check on xp returned by bexpand
printstr must not return immediately if the string is null
---
builtins/printf.def | 24 ++++++++++--------------
1 file changed, 10 insertions(+), 14 deletions(-)
diff --git a/builtins/printf.def b/builtins/printf.def
index d39a6d3..1037b5c 100644
--- a/builtins/printf.def
+++ b/builtins/printf.def
@@ -543,22 +543,19 @@ printf_builtin (list)
ch = rlen = r = 0;
xp = bexpand (p, strlen (p), &ch, &rlen);
- if (xp)
+ /* Have to use printstr because of possible NUL bytes
+ in XP -- printf does not handle that well. */
+ r = printstr (start, xp, rlen, fieldwidth, precision);
+ if (r < 0)
{
- /* Have to use printstr because of possible NUL bytes
- in XP -- printf does not handle that well. */
- r = printstr (start, xp, rlen, fieldwidth, precision);
- if (r < 0)
+ if (ferror (stdout) == 0)
{
- if (ferror (stdout) == 0)
- {
- sh_wrerror ();
- clearerr (stdout);
- }
- retval = EXECUTION_FAILURE;
+ sh_wrerror ();
+ clearerr (stdout);
}
- free (xp);
+ retval = EXECUTION_FAILURE;
}
+ free (xp);
if (ch || r < 0)
PRETURN (retval);
@@ -711,8 +708,7 @@ printstr (fmt, string, len, fieldwidth, precision)
int fw, pr; /* fieldwidth and precision */
intmax_t mfw, mpr;
- if (string == 0 || len == 0)
- return 0;
+ if (string == 0) string = "";
#if 0
s = fmt;
--
2.10.0
