Replace "keep history" magic value by a constant (#1759)

I think the use of a magic value repeated many times in the code is prone to have some errors made by people not knowing its meaning. Using a constant is a bit more safe. Judging by some comments in the code, I am not the only one.

1 files changed, 2 insertions, 4 deletions

diff --git a/app/Controllers/feedController.php b/app/Controllers/feedController.php
index 2793577d5..884172112 100755
--- a/app/Controllers/feedController.php
+++ b/app/Controllers/feedController.php
@@ -317,10 +317,8 @@ class FreshRSS_feed_Controller extends Minz_ActionController {
 
 			$feed_history = $feed->keepHistory();
 			if ($isNewFeed) {
-				$feed_history = -1; //∞
-			} elseif ($feed_history == -2) {
-				// TODO: -2 must be a constant!
-				// -2 means we take the default value from configuration
+				$feed_history = FreshRSS_Feed::KEEP_HISTORY_INFINITE;
+			} elseif (FreshRSS_Feed::KEEP_HISTORY_DEFAULT === $feed_history) {
 				$feed_history = FreshRSS_Context::$user_conf->keep_history_default;
 			}
 			$needFeedCacheRefresh = false;