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, 1 insertions, 3 deletions

diff --git a/app/Controllers/entryController.php b/app/Controllers/entryController.php
index bd8b65b2b..9c6b248a9 100755
--- a/app/Controllers/entryController.php
+++ b/app/Controllers/entryController.php
@@ -177,9 +177,7 @@ class FreshRSS_entry_Controller extends Minz_ActionController {
 
 		foreach ($feeds as $feed) {
 			$feed_history = $feed->keepHistory();
-			if ($feed_history == -2) {
-				// TODO: -2 must be a constant!
-				// -2 means we take the default value from configuration
+			if (FreshRSS_Feed::KEEP_HISTORY_DEFAULT === $feed_history) {
 				$feed_history = FreshRSS_Context::$user_conf->keep_history_default;
 			}