musl - musl - an implementation of the standard library for Linux-based systems

diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index f13fbe10..2c4fdf3d 100644
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c

@@ -552,7 +552,7 @@ static int printf_core(FILE *f, const char *fmt, va_list *ap, union arg *nl_arg,

fl |= ALT_FORM;

case 'x': case 'X':

a = fmt_x(arg.i, z, t&32);

- if (fl & ALT_FORM) prefix+=(t>>4), pl=2;

+ if (arg.i && (fl & ALT_FORM)) prefix+=(t>>4), pl=2;

if (0) {

case 'o':

a = fmt_o(arg.i, z);