Don't clean up msn idata when closing an open-append mailbox. (see #3942)

This is a continuation of commit 59a2125b49f2 with changes made in the
default branch.

Thanks again to Will Yardley for helping test the imap read-headers
changes and discovering this bug.

diff --git a/imap/imap.c b/imap/imap.c
index 474c2c8ad834f4924ea606c29cb9d90aa104d5a7..9de4332d0f826af8b494aa821be8f5f228a39ced 100644 (file)
--- a/imap/imap.c
+++ b/imap/imap.c
@@ -1411,6 +1411,9 @@ int imap_close_mailbox(struct Context *ctx)
     idata->ctx = NULL;
 
     hash_destroy(&idata->uid_hash, NULL);
+    FREE(&idata->msn_index);
+    idata->msn_index_size = 0;
+    idata->max_msn = 0;
 
     for (i = 0; i < IMAP_CACHE_LEN; i++)
     {