Commit 6201bd6 for zlib

commit 6201bd6046fc0d5bc6b665ae6a32cb54e857d5b4
Author: Naveed Khan <dxbnaveed.k@gmail.com>
Date:   Sun Oct 18 15:06:03 2026 +0530

    Fix NULL dereference on repeated minizip zipAlreadyThere() calls.

    block_stop() did not clear block->node, which is what block_end()
    and block_get() check to see that the central directory reader was
    stopped. After an invalid central directory, the next
    zipAlreadyThere() call would read through the NULL next pointer.

diff --git a/contrib/minizip/zip.c b/contrib/minizip/zip.c
index b2db1df..05d5388 100644
--- a/contrib/minizip/zip.c
+++ b/contrib/minizip/zip.c
@@ -309,6 +309,7 @@ local void block_init(block_t *block, linkedlist_data *list) {
    data is added to the datablocks. This is invoked if the central directory is
    invalid, so there is no longer any point in attempting to interpret it. */
 local void block_stop(block_t *block) {
+    block->node = NULL;
     block->left = 0;
     block->next = NULL;
 }