fix swprintf handling of nul character in output

[musl] / src / stdio / vswprintf.c

diff --git a/src/stdio/vswprintf.c b/src/stdio/vswprintf.c
index 31ea187..fc223cf 100644 (file)
--- a/src/stdio/vswprintf.c
+++ b/src/stdio/vswprintf.c
@@ -1,4 +1,9 @@
 #include "stdio_impl.h"
+#include <limits.h>
+#include <errno.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <wchar.h>
 
 struct cookie {
        wchar_t *ws;
@@ -10,30 +15,40 @@ static size_t sw_write(FILE *f, const unsigned char *s, size_t l)
        size_t l0 = l;
        int i = 0;
        struct cookie *c = f->cookie;
-       while (c->l && l && (i=mbtowc(c->ws, s, l))>=0) {
+       if (s!=f->wbase && sw_write(f, f->wbase, f->wpos-f->wbase)==-1)
+               return -1;
+       while (c->l && l && (i=mbtowc(c->ws, (void *)s, l))>=0) {
+               if (!i) i=1;
                s+=i;
                l-=i;
                c->l--;
                c->ws++;
        }
        *c->ws = 0;
-       return i<0 ? i : l0;
+       if (i < 0) {
+               f->wpos = f->wbase = f->wend = 0;
+               f->flags |= F_ERR;
+               return i;
+       }
+       f->wend = f->buf + f->buf_size;
+       f->wpos = f->wbase = f->buf;
+       return l0;
 }
 
-int vswprintf(wchar_t *s, size_t n, const wchar_t *fmt, va_list ap)
+int vswprintf(wchar_t *restrict s, size_t n, const wchar_t *restrict fmt, va_list ap)
 {
        int r;
-       FILE f;
        unsigned char buf[256];
        struct cookie c = { s, n-1 };
+       FILE f = {
+               .lbf = EOF,
+               .write = sw_write,
+               .lock = -1,
+               .buf = buf,
+               .buf_size = sizeof buf,
+               .cookie = &c,
+       };
 
-       memset(&f, 0, sizeof(FILE));
-       f.lbf = EOF;
-       f.write = sw_write;
-       f.buf_size = sizeof buf;
-       f.buf = buf;
-       f.lock = -1;
-       f.cookie = &c;
        if (!n) {
                return -1;
        } else if (n > INT_MAX) {
@@ -41,6 +56,6 @@ int vswprintf(wchar_t *s, size_t n, const wchar_t *fmt, va_list ap)
                return -1;
        }
        r = vfwprintf(&f, fmt, ap);
-       __oflow(&f);
+       sw_write(&f, 0, 0);
        return r>=n ? -1 : r;
 }