Parametrise the different ways in which the payload is reset

In FS#43434, Downloads which fail and are restarted on a different server
will resume and may display a negative download speed. The payload's progress
in libalpm was not properly reset which ultimately caused terminal noise
because the line width calculation assumes positive download speeds.

This patch fixes the incomplete reset of the payload by mimicing what
be_sync.c:alpm_db_update() does over in sync.c:download_single_file().
The new dload.c:_alpm_dload_payload_reset_for_retry() extends beyond the
current behavior by updating initial_size and prevprogress for this case.
This makes pacman reset the progress properly in the next invocation of the
callback and display positive download speeds.

Fixes FS#43434.

Signed-off-by: Martin Kühne <mysatyre@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

3 files changed, 12 insertions, 3 deletions

diff --git a/lib/libalpm/dload.c b/lib/libalpm/dload.c
index ccd70d99..e8896098 100644
--- a/lib/libalpm/dload.c
+++ b/lib/libalpm/dload.c
@@ -722,4 +722,14 @@ void _alpm_dload_payload_reset(struct dload_payload *payload)
 	memset(payload, '\0', sizeof(*payload));
 }
 
+void _alpm_dload_payload_reset_for_retry(struct dload_payload *payload)
+{
+	ASSERT(payload, return);
+
+	FREE(payload->fileurl);
+	payload->initial_size += payload->prevprogress;
+	payload->prevprogress = 0;
+	payload->unlink_on_fail = 0;
+}
+
 /* vim: set noet: */
diff --git a/lib/libalpm/dload.h b/lib/libalpm/dload.h
index 427c4860..3459665b 100644
--- a/lib/libalpm/dload.h
+++ b/lib/libalpm/dload.h
@@ -47,6 +47,7 @@ struct dload_payload {
 };
 
 void _alpm_dload_payload_reset(struct dload_payload *payload);
+void _alpm_dload_payload_reset_for_retry(struct dload_payload *payload);
 
 int _alpm_download(struct dload_payload *payload, const char *localpath,
 		char **final_file, const char **final_url);
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index 837639d4..d3be09e4 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -946,9 +946,7 @@ static int download_single_file(alpm_handle_t *handle, struct dload_payload *pay
 			EVENT(handle, &event);
 			return 0;
 		}
-
-		FREE(payload->fileurl);
-		payload->unlink_on_fail = 0;
+		_alpm_dload_payload_reset_for_retry(payload);
 	}
 
 	event.type = ALPM_EVENT_PKGDOWNLOAD_FAILED;