dload: ensure callback is always initialized once

Frontends rely on an initialization call for setup between downloads.
Checking for intialization after checking for a completed download can
skip initialization in cases where files are small enough to be
downloaded all at once (FS#56408).  Relying on previous download size
can result in multiple initializations if there are multiple
non-transfer events prior to the download starting (fS#56468).

Introduce a new cb_initialized variable to the payload struct and use it
to ensure that the callback is initialized exactly once prior to any
actual events.

Fixes FS#56408, FS#56468

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/lib/libalpm/dload.h b/lib/libalpm/dload.h
index 6ca775a7..ac948528 100644
--- a/lib/libalpm/dload.h
+++ b/lib/libalpm/dload.h
@@ -41,6 +41,7 @@ struct dload_payload {
 	int errors_ok;
 	int unlink_on_fail;
 	int trust_remote_name;
+	int cb_initialized;
 #ifdef HAVE_LIBCURL
 	CURLcode curlerr;       /* last error produced by curl */
 #endif