Commit e3dc0a8 for zlib

commit e3dc0a85b7032e98380dec011bc8f2c2ee0d8fca
Author: Mark Adler <git@madler.net>
Date:   Sun Apr 5 15:14:04 2026 -0700

    Avoid undefined behavior in gzwrite.c.

    Adding to NULL is undefined.

diff --git a/gzwrite.c b/gzwrite.c
index 13a3700..b5026e5 100644
--- a/gzwrite.c
+++ b/gzwrite.c
@@ -383,7 +383,8 @@ local int gz_vacate(gz_statep state) {
     z_streamp strm;

     strm = &(state->strm);
-    if (strm->next_in + strm->avail_in <= state->in + state->size)
+    if (strm->next_in == NULL ||
+        strm->next_in + strm->avail_in <= state->in + state->size)
         return 0;
     (void)gz_comp(state, Z_NO_FLUSH);
     if (strm->avail_in == 0) {