Add null/empty string parameter value case in BBCode::convert

- Remove obsolete coalesce operator uses

include/enotify.php

@@ -465,7 +465,7 @@ function notification($params)
 	if ($show_in_notification_page) {
 		$notification = DI::notify()->insert([
 			'name'          => $params['source_name'] ?? '',
-			'name_cache'    => substr(strip_tags(BBCode::convert($params['source_name'] ?? '')), 0, 255),
+			'name_cache'    => substr(strip_tags(BBCode::convert($params['source_name'])), 0, 255),
 			'url'           => $params['source_link'] ?? '',
 			'photo'         => $params['source_photo'] ?? '',
 			'link'          => $itemlink ?? '',

mod/cal.php

@@ -78,7 +78,7 @@ function cal_init(App $a)
 		'$photo' => $profile['photo'],
 		'$addr' => $profile['addr'] ?: '',
 		'$account_type' => $account_type,
-		'$about' => BBCode::convert($profile['about'] ?: ''),
+		'$about' => BBCode::convert($profile['about']),
 	]);
 
 	$cal_widget = Widget\CalendarExport::getHTML();

mod/photos.php

@@ -82,7 +82,7 @@ function photos_init(App $a) {
 			'$photo' => $profile['photo'],
 			'$addr' => $profile['addr'] ?? '',
 			'$account_type' => $account_type,
-			'$about' => BBCode::convert($profile['about'] ?? ''),
+			'$about' => BBCode::convert($profile['about']),
 		]);
 
 		$albums = Photo::getAlbums($a->data['user']['uid']);

mod/videos.php

@@ -67,7 +67,7 @@ function videos_init(App $a)
 			'$photo' => $profile['photo'],
 			'$addr' => $profile['addr'] ?? '',
 			'$account_type' => $account_type,
-			'$about' => BBCode::convert($profile['about'] ?? ''),
+			'$about' => BBCode::convert($profile['about']),
 		]);
 
 		// If not there, create 'aside' empty

src/Content/Text/BBCode.php

@@ -1252,8 +1252,13 @@ class BBCode
 	 * @return string
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function convert($text, $try_oembed = true, $simple_html = self::INTERNAL, $for_plaintext = false)
+	public static function convert(string $text = null, $try_oembed = true, $simple_html = self::INTERNAL, $for_plaintext = false)
 	{
+		// Accounting for null default column values
+		if (is_null($text) || $text === '') {
+			return '';
+		}
+
 		$a = DI::app();
 
 		$text = self::performWithEscapedTags($text, ['code'], function ($text) use ($try_oembed, $simple_html, $for_plaintext, $a) {

src/Model/Notify.php

@@ -70,7 +70,7 @@ class Notify extends BaseModel
 	private function setNameCache()
 	{
 		try {
-			$this->name_cache = strip_tags(BBCode::convert($this->source_name ?? ''));
+			$this->name_cache = strip_tags(BBCode::convert($this->source_name));
 		} catch (InternalServerErrorException $e) {
 		}
 	}