Don't automatically retry failures, and consider never-expiring results to always remain valid

src/database-backends/postgresql/queries/get-task-stream.js

@@ -34,7 +34,10 @@ function makeFillQuery(withDependencies) {
 					WHERE
 						results.is_successful = TRUE
 						AND results.is_invalidated = FALSE
-						AND results.expires_at > NOW()
+						AND (
+							results.expires_at > NOW()
+							OR results.expires_at IS NULL
+						)
 				),
 				counts AS (
 					SELECT item_id, COUNT(task) AS count FROM satisfied GROUP BY item_id
@@ -68,9 +71,17 @@ function makeFillQuery(withDependencies) {
 				item_id = full_candidates.item_id
 				AND results.task = :task
 				AND results.task_version = :taskVersion
-				AND results.is_successful = TRUE
+				AND (
+					results.is_successful = FALSE
+					OR (
+						results.is_successful = TRUE
 						AND results.is_invalidated = FALSE
-				AND results.expires_at > NOW()
+						AND (
+							results.expires_at > NOW()
+							OR results.expires_at IS NULL
+						)
+					)
+				)
 		)
 	`;
 }