setvbuf: return failure if mode is invalid

[musl] / src / stdio / setvbuf.c

diff --git a/src/stdio/setvbuf.c b/src/stdio/setvbuf.c
index 06ea296..523dddc 100644 (file)
--- a/src/stdio/setvbuf.c
+++ b/src/stdio/setvbuf.c
@@ -12,13 +12,15 @@ int setvbuf(FILE *restrict f, char *restrict buf, int type, size_t size)
 
        if (type == _IONBF) {
                f->buf_size = 0;
-       } else {
+       } else if (type == _IOLBF || type == _IOFBF) {
                if (buf && size >= UNGET) {
                        f->buf = (void *)(buf + UNGET);
                        f->buf_size = size - UNGET;
                }
                if (type == _IOLBF && f->buf_size)
                        f->lbf = '\n';
+       } else {
+               return -1;
        }
 
        f->flags |= F_SVB;