[5.1] SEF: Implementing index.php behavior

administrator/language/en-GB/plg_system_sef.ini

@@ -5,6 +5,8 @@
 
 PLG_SEF_DOMAIN_DESCRIPTION="If your site can be accessed through more than one domain enter the preferred (sometimes referred to as canonical) domain here. <br><strong>Note:</strong> https://example.com and https://www.example.com are different domains."
 PLG_SEF_DOMAIN_LABEL="Site Domain"
+PLG_SEF_INDEXPHP_DESCRIPTION="This option enables a stricter handling of 'index.php' in URLs when 'Use URL Rewriting' is enabled in Global Configuration. It will remove 'index.php' if a URL still contains it and redirect incoming requests with 'index.php' to the version without the 'index.php'."
+PLG_SEF_INDEXPHP_LABEL="Strict handling of index.php"
 PLG_SEF_TRAILINGSLASH_DESCRIPTION="Force Joomla to only use URLs with or without trailing slash. When set, this will force the right URL with redirects and is only applied when 'Add suffix to URL' is disabled."
 PLG_SEF_TRAILINGSLASH_LABEL="Trailing slash for URLs"
 PLG_SEF_TRAILINGSLASH_OPTION_NONE="No change"

plugins/system/sef/sef.xml

@@ -31,6 +31,19 @@
 					validate="url"
 				/>
 
+				<field
+					name="indexphp"
+					type="radio"
+					label="PLG_SEF_INDEXPHP_LABEL"
+					description="PLG_SEF_INDEXPHP_DESCRIPTION"
+					layout="joomla.form.field.radio.switcher"
+					default="0"
+					filter="boolean"
+				>
+					<option value="0">JNO</option>
+					<option value="1">JYES</option>
+				</field>
+
 				<field
 					name="trailingslash"
 					type="list"

plugins/system/sef/src/Extension/Sef.php

@@ -68,23 +68,30 @@ public static function getSubscribedEvents(): array
     public function onAfterInitialiseRouter(AfterInitialiseRouterEvent $event)
     {
         if (
-            !is_a($event->getRouter(), SiteRouter::class)
-            || !$this->app->get('sef')
-            || $this->app->get('sef_suffix')
-            || !$this->params->get('trailingslash')
+            is_a($event->getRouter(), SiteRouter::class)
+            && $this->app->get('sef_rewrite')
+            && $this->params->get('indexphp')
         ) {
-            return;
+            // Enforce removing index.php with a redirect
+            $event->getRouter()->attachParseRule([$this, 'removeIndexphp'], SiteRouter::PROCESS_BEFORE);
         }
 
-        if ($this->params->get('trailingslash') == 1) {
-            // Remove trailingslash
-            $event->getRouter()->attachBuildRule([$this, 'removeTrailingSlash'], SiteRouter::PROCESS_AFTER);
-        } elseif ($this->params->get('trailingslash') == 2) {
-            // Add trailingslash
-            $event->getRouter()->attachBuildRule([$this, 'addTrailingSlash'], SiteRouter::PROCESS_AFTER);
-        }
+        if (
+            is_a($event->getRouter(), SiteRouter::class)
+            && $this->app->get('sef')
+            && !$this->app->get('sef_suffix')
+            && $this->params->get('trailingslash')
+        ) {
+            if ($this->params->get('trailingslash') == 1) {
+                // Remove trailingslash
+                $event->getRouter()->attachBuildRule([$this, 'removeTrailingSlash'], SiteRouter::PROCESS_AFTER);
+            } elseif ($this->params->get('trailingslash') == 2) {
+                // Add trailingslash
+                $event->getRouter()->attachBuildRule([$this, 'addTrailingSlash'], SiteRouter::PROCESS_AFTER);
+            }
 
-        $event->getRouter()->attachParseRule([$this, 'enforceTrailingSlash'], SiteRouter::PROCESS_BEFORE);
+            $event->getRouter()->attachParseRule([$this, 'enforceTrailingSlash'], SiteRouter::PROCESS_BEFORE);
+        }
     }
 
     /**
@@ -250,6 +257,38 @@ function ($match) use ($base, $protocols) {
         $this->getApplication()->setBody($buffer);
     }
 
+    /**
+     * Enforce removal of index.php with a redirect
+     *
+     * @param   Router  &$router  Router object.
+     * @param   Uri     &$uri     Uri object.
+     *
+     * @return  void
+     *
+     * @since   __DEPLOY_VERSION__
+     */
+    public function removeIndexphp(&$router, &$uri)
+    {
+        // We only want to redirect on GET requests
+        if ($this->app->getInput()->getMethod() !== 'GET') {
+            return;
+        }
+
+        $origUri = Uri::getInstance();
+
+        if (substr($origUri->getPath(), -9) === 'index.php') {
+            // Remove trailing index.php
+            $origUri->setPath(substr($origUri->getPath(), 0, -9));
+            $this->app->redirect($origUri->toString(), 301);
+        }
+
+        if (substr($origUri->getPath(), \strlen(Uri::base(true)), 11) === '/index.php/') {
+            // Remove leading index.php
+            $origUri->setPath(Uri::base(true) . substr($origUri->getPath(), \strlen(Uri::base(true)) + 10));
+            $this->app->redirect($origUri->toString(), 301);
+        }
+    }
+
     /**
      * Remove any trailing slash from URLs built in Joomla
      *