corresponds to glibc bug
https://sourceware.org/bugzilla/show_bug.cgi?id=28038...

basically just "make sure you've terminated the buffer _before_ returning".

diff --git a/lib/libc/stdio/getdelim.c b/lib/libc/stdio/getdelim.c
index d709a3d18e1..292920e79c9 100644
--- a/lib/libc/stdio/getdelim.c
+++ b/lib/libc/stdio/getdelim.c
@@ -119,13 +119,11 @@ getdelim(char **__restrict buf, size_t *__restrict buflen,

        FUNLOCKFILE(fp);

-       /* POSIX demands we return -1 on EOF. */
-       if (off == 0)
-               return -1;
-
        if (*buf != NULL)
                *(*buf + off) = '\0';
-       return off;
+
+       /* POSIX demands we return -1 on EOF. */
+       return (off == 0) ? -1 : off;

 error:
        fp->_flags |= __SERR;