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

diff --git a/src/stdio/vswscanf.c b/src/stdio/vswscanf.c
index 4396d7df..4c39f806 100644
--- a/src/stdio/vswscanf.c
+++ b/src/stdio/vswscanf.c

@@ -17,7 +17,7 @@ static size_t wstring_read(FILE *f, unsigned char *buf, size_t len)

f->rend = f->buf + k;

f->cookie = (void *)src;

- if (!len) return 0;

+ if (!len || !k) return 0;

*buf = *f->rpos++;

return 1;