lib-storage: mailbox_header_lookup_unref(NULL) should be a no-op

diff --git a/src/lib-storage/mailbox-header.c b/src/lib-storage/mailbox-header.c
index 2def864985e8a13a30486109afccff687243d6f9..434e4191af6dd492b8ec015bf7dc173e4f796ac3 100644 (file)
--- a/src/lib-storage/mailbox-header.c
+++ b/src/lib-storage/mailbox-header.c
@@ -79,6 +79,9 @@ void mailbox_header_lookup_unref(struct mailbox_header_lookup_ctx **_ctx)
 {
        struct mailbox_header_lookup_ctx *ctx = *_ctx;
 
+       if (ctx == NULL)
+               return;
+
        *_ctx = NULL;
 
        i_assert(ctx->refcount > 0);