fix some length calculations in memory streams

[musl] / src / stdio / open_wmemstream.c

diff --git a/src/stdio/open_wmemstream.c b/src/stdio/open_wmemstream.c
index 5402ca1..3bc0f25 100644 (file)
--- a/src/stdio/open_wmemstream.c
+++ b/src/stdio/open_wmemstream.c
@@ -39,13 +39,13 @@ static size_t wms_write(FILE *f, const unsigned char *buf, size_t len)
        struct cookie *c = f->cookie;
        size_t len2;
        wchar_t *newbuf;
-       if (len > c->space - c->pos) {
+       if (len >= c->space - c->pos) {
                len2 = 2*c->space+1 | c->space+len+1;
                if (len2 > SSIZE_MAX/4) return 0;
                newbuf = realloc(c->buf, len2*4);
                if (!newbuf) return 0;
                *c->bufp = c->buf = newbuf;
-               memset(c->buf + c->space, 0, len2 - c->space);
+               memset(c->buf + c->space, 0, 4*(len2 - c->space));
                c->space = len2;
        }