Fix priority of language-only redirect matches. #234

Close #234.

CHANGELOG.md

@@ -8,6 +8,17 @@
 - Language API: Use fallback names for languages, see
 [issue #224](https://github.com/inpsyde/multilingual-press/issues/224).
 
+## 2.4.8
+- Install/Uninstall: Prevent potential PHP notice due to deprecated `wp_get_sites()` function, see
+[issue #229](https://github.com/inpsyde/multilingual-press/issues/229) and
+[issue #236](https://github.com/inpsyde/multilingual-press/issues/236).
+- Language Manager: Fix HTTP code of _Chinese (Singapore)_, see
+[issue #232](https://github.com/inpsyde/multilingual-press/issues/232).
+- Language Manager: Fix HTTP code of _French (Switzerland)_, see
+[issue #233](https://github.com/inpsyde/multilingual-press/issues/233).
+- Redirect: Fix priority of language-only redirect matches, see
+[issue #234](https://github.com/inpsyde/multilingual-press/issues/234).
+
 ## 2.4.7
 - CSS: Use font weight "600" instead of "bold", see
 [Native Fonts in 4.6](https://make.wordpress.org/core/2016/07/07/native-fonts-in-4-6/).

src/inc/redirect/Mlp_Language_Negotiation.php

@@ -21,6 +21,11 @@ class Mlp_Language_Negotiation implements Mlp_Language_Negotiation_Interface {
 	 */
 	private $language_api;
 
+	/**
+	 * @var float
+	 */
+	private $language_only_priority_factor;
+
 	/**
 	 * @var AcceptHeaderParser
 	 */
@@ -35,6 +40,20 @@ public function __construct( Mlp_Language_Api_Interface $language_api, AcceptHea
 		$this->language_api = $language_api;
 
 		$this->parser = $parser ?: new AcceptLanguageParser();
+
+		/**
+		 * Filters the factor used to compute the priority of language-only matches. This has to be between 0 and 1.
+		 *
+		 * @see   get_user_priority()
+		 * @since 2.4.8
+		 *
+		 * @param float $factor The factor used to compute the priority of language-only matches.
+		 */
+		$factor = (float) apply_filters( 'multilingualpress.language_only_priority_factor', .7 );
+		$factor = min( 1, $factor );
+		$factor = max( 0, $factor );
+
+		$this->language_only_priority_factor = $factor;
 	}
 
 	/**
@@ -148,15 +167,17 @@ private function sort_priorities( $a, $b ) {
 	 */
 	private function get_user_priority( Language $language, array $user ) {
 
-		$lang_http = $language->name( 'http_name' );
+		$lang_http = strtolower( $language->name( 'http_name' ) );
 
-		if ( isset ( $user[ $lang_http ] ) )
+		if ( isset( $user[ $lang_http ] ) ) {
 			return $user[ $lang_http ];
+		}
 
-		$lang_short = $language->name( 'language_short' );
+		$lang_short = strtolower( $language->name( 'language_short' ) );
 
-		if ( isset ( $user[ $lang_short ] ) )
-			return $user[ $lang_short ];
+		if ( isset( $user[ $lang_short ] ) ) {
+			return $this->language_only_priority_factor * $user[ $lang_short ];
+		}
 
 		return 0;
 	}
@@ -177,12 +198,13 @@ private function parse_accept_header( $accept_header ) {
 		$out = [];
 
 		foreach ( $fields as $name => $priority ) {
+			$name = strtolower( $name );
 
 			$out[ $name ] = $priority;
 
 			$short = $this->get_short_form( $name );
 
-			if ( ( $short !== $name ) && ! isset ( $out[ $short ] ) )
+			if ( $short && ( $short !== $name ) && ! isset ( $out[ $short ] ) )
 				$out[ $short ] = $priority;
 		}