From 71c8d8d365f62ecacceaee9f5fe70c344a18dd4b Mon Sep 17 00:00:00 2001
From: Andrew Dolgov <noreply@fakecake.org>
Date: Tue, 8 Dec 2020 16:59:58 +0300
Subject: [PATCH] queryFeedHeadlines:  - there should be no need for DISTINCT
 query when checking for first id  - fix DISTINCT query part being undefined
 when browsing by tags  - add query debugging for tags

---
 classes/feeds.php | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/classes/feeds.php b/classes/feeds.php
index c66fe0207..b8c5227aa 100755
--- a/classes/feeds.php
+++ b/classes/feeds.php
@@ -1785,7 +1785,7 @@ class Feeds extends Handler_Protected {
 
 			if (!$search && !$skip_first_id_check) {
 				// if previous topmost article id changed that means our current pagination is no longer valid
-				$query = "SELECT $distinct_qpart
+				$query = "SELECT
 							ttrss_entries.id,
 							date_entered,
 							$yyiw_qpart,
@@ -1871,6 +1871,13 @@ class Feeds extends Handler_Protected {
 		} else {
 			// browsing by tag
 
+			if (DB_TYPE == "pgsql") {
+				$distinct_columns = str_replace("desc", "", strtolower($order_by));
+				$distinct_qpart = "DISTINCT ON (id, $distinct_columns)";
+			} else {
+				$distinct_qpart = "DISTINCT"; //fallback
+			}
+
 			$query = "SELECT $distinct_qpart
 							date_entered,
 							guid,
@@ -1912,6 +1919,10 @@ class Feeds extends Handler_Protected {
 
 			//if ($_REQUEST["debug"]) print $query;
 
+			if ($_REQUEST["debug"]) {
+				print "\n*** TAGS QUERY ***\n$query\n";
+			}
+
 			$res = $pdo->query($query);
 		}