PDO refactoring for code simplification (#2522)

* PDO refactor

* Automatic prefix when using the syntax `_tableName`
* Uniformity: MySQL is now PDO::ATTR_EMULATE_PREPARES = false just like SQLite and PostgreSQL, with consequences such as only one statement per query
* Use PDO methods exec(), query(), prepare() + execute() in a more efficient way
* Remove auto-update SQL code for versions older than FreshRSS 1.5 (3 years old)
* The name of the default category is set in PHP instead of in the DB (simplies SQL and allows changing the name according to the FreshRSS language)
* Rename `->bd` to `->pdo` (less of a frenshism, and more informative)
* Fix some requests, which were not compatible with MySQL prepared statements

* Whitespace

* Fix syntax for PostgreSQL sequences

+ MySQL install

* Minor formatting

* Fix lastInsertId for PostgreSQL

* Use PHP 5.6+ const

Take advantage of https://github.com/FreshRSS/FreshRSS/pull/2527
https://www.php.net/manual/en/migration56.new-features.php

* A bit of forgotten PHP 5.6 simplification for cURL

* Forgotten $s

* Mini fix custom user config

https://github.com/FreshRSS/FreshRSS/pull/2490/files#r326290346

* More work on install.php but not finished

* install.php working

* More cleaning of PDO in install

* Even more simplification

Take advantage of PDO->exec() to run multiple statements

* Disallow changing the name of the default category

https://github.com/FreshRSS/FreshRSS/pull/2522#discussion_r326967724

1 files changed, 5 insertions, 6 deletions

diff --git a/lib/lib_rss.php b/lib/lib_rss.php
index 1bba60c36..854126b54 100644
--- a/lib/lib_rss.php
+++ b/lib/lib_rss.php
@@ -535,17 +535,16 @@ function _i($icon, $url_only = false) {
 }
 
 
-$SHORTCUT_KEYS = array(	//No const for < PHP 5.6 compatibility
+const SHORTCUT_KEYS = [
 			'0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
 			'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
 			'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
 			'F1', 'F2', 'F3', 'F4', 'F5', 'F6', 'F7', 'F8', 'F9', 'F10', 'F11', 'F12',
 			'ArrowDown', 'ArrowLeft', 'ArrowRight', 'ArrowUp', 'Backspace', 'Delete',
 			'End', 'Enter', 'Escape', 'Home', 'Insert', 'PageDown', 'PageUp', 'Space', 'Tab',
-		);
+		];
 
 function validateShortcutList($shortcuts) {
-	global $SHORTCUT_KEYS;
 	$legacy = array(
 			'down' => 'ArrowDown', 'left' => 'ArrowLeft', 'page_down' => 'PageDown', 'page_up' => 'PageUp',
 			'right' => 'ArrowRight', 'up' => 'ArrowUp',
@@ -554,17 +553,17 @@ function validateShortcutList($shortcuts) {
 	$shortcuts_ok = array();
 
 	foreach ($shortcuts as $key => $value) {
-		if (in_array($value, $SHORTCUT_KEYS)) {
+		if (in_array($value, SHORTCUT_KEYS)) {
 			$shortcuts_ok[$key] = $value;
 		} elseif (isset($legacy[$value])) {
 			$shortcuts_ok[$key] = $legacy[$value];
 		} else {	//Case-insensitive search
 			if ($upper === null) {
-				$upper = array_map('strtoupper', $SHORTCUT_KEYS);
+				$upper = array_map('strtoupper', SHORTCUT_KEYS);
 			}
 			$i = array_search(strtoupper($value), $upper);
 			if ($i !== false) {
-				$shortcuts_ok[$key] = $SHORTCUT_KEYS[$i];
+				$shortcuts_ok[$key] = SHORTCUT_KEYS[$i];
 			}
 		}
 	}