diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index c6c50a4..8dd93b0 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -295,6 +295,8 @@ alpm_list_t SYMEXPORT *alpm_find_group_pkgs(alpm_list_t *dbs,
 /** Compute the size of the files that will be downloaded to install a
  * package.
  * @param newpkg the new package to upgrade to
+ * @return 0 on success, 1 if we have a partial file, 2 if we are
+ * downloading deltas, -1 on failure
  */
 static int compute_download_size(alpm_pkg_t *newpkg)
 {
@@ -310,6 +312,12 @@ static int compute_download_size(alpm_pkg_t *newpkg)
 		return 0;
 	}
 
+	/* cleanup from any prior calls to this function */
+	alpm_list_free(newpkg->delta_path);
+	newpkg->delta_path = NULL;
+	newpkg->download_size = 0;
+	newpkg->infolevel &= !INFRQ_DSIZE;
+
 	ASSERT(newpkg->filename != NULL, RET_ERR(handle, ALPM_ERR_PKG_INVALID_NAME, -1));
 	fname = newpkg->filename;
 	fpath = _alpm_filecache_find(handle, fname);
@@ -343,6 +351,8 @@ static int compute_download_size(alpm_pkg_t *newpkg)
 		if(newpkg->delta_path && (dltsize < newpkg->size * handle->deltaratio)) {
 			_alpm_log(handle, ALPM_LOG_DEBUG, "using delta size\n");
 			size = dltsize;
+			/* tell the caller that we are downloading deltas */
+			ret = 2;
 		} else {
 			_alpm_log(handle, ALPM_LOG_DEBUG, "using package size\n");
 			size = newpkg->size;