FIX Catch database exceptions in middleware when DB is not ready, set session ID after delegation

code/Middleware/InitStateMiddleware.php

@@ -7,6 +7,7 @@ use SilverStripe\Control\HTTPRequest;
 use SilverStripe\Control\Middleware\HTTPMiddleware;
 use SilverStripe\Core\Config\Configurable;
 use SilverStripe\Core\Injector\Injector;
+use SilverStripe\ORM\Connect\DatabaseException;
 use SilverStripe\Subsites\Model\Subsite;
 use SilverStripe\Subsites\State\SubsiteState;
 
@@ -27,28 +28,35 @@ class InitStateMiddleware implements HTTPMiddleware
 
     public function process(HTTPRequest $request, callable $delegate)
     {
-        // Initialise and register the State
+        try {
-        $state = SubsiteState::create();
+            // Initialise and register the State
-        Injector::inst()->registerService($state);
+            $state = SubsiteState::create();
+            Injector::inst()->registerService($state);
 
-        // Detect whether the request was made in the CMS area (or other admin-only areas)
+            // Detect whether the request was made in the CMS area (or other admin-only areas)
-        $isAdmin = $this->getIsAdmin($request);
+            $isAdmin = $this->getIsAdmin($request);
-        $state->setUseSessions($isAdmin);
+            $state->setUseSessions($isAdmin);
 
-        // Detect the subsite ID
+            // Detect the subsite ID
-        $subsiteId = $this->detectSubsiteId($request);
+            $subsiteId = $this->detectSubsiteId($request);
-        $state->setSubsiteId($subsiteId);
+            $state->setSubsiteId($subsiteId);
 
-        // Persist to the session if using the CMS
+            // Persist to the session if using the CMS
-        if ($state->getUseSessions()) {
+            if ($state->getUseSessions()) {
-            $original = $request->getSession()->get('SubsiteID');
+                $originalSubsiteId = $request->getSession()->get('SubsiteID');
-            $request->getSession()->set('SubsiteID', $subsiteId);
+            }
 
-            // Track session changes
+            return $delegate($request);
-            $state->setSessionWasChanged($subsiteId === $original);
+        } catch (DatabaseException $ex) {
+            // No-op, database is not ready
+        } finally {
+            if ($state->getUseSessions()) {
+                // Track session changes
+                $request->getSession()->set('SubsiteID', $subsiteId);
+
+                $state->setSessionWasChanged($subsiteId === $originalSubsiteId);
+            }
         }
-
-        return $delegate($request);
     }
 
     /**

code/extensions/ControllerSubsites.php

@@ -15,7 +15,7 @@ class ControllerSubsites extends Extension
     {
         if ($subsite = Subsite::currentSubsite()) {
             if ($theme = $subsite->Theme) {
-                SSViewer::add_themes([$theme]);
+                SSViewer::set_themes([$theme, SSViewer::DEFAULT_THEME]);
             }
         }
     }

code/extensions/LeftAndMainSubsites.php

@@ -267,13 +267,18 @@ class LeftAndMainSubsites extends LeftAndMainExtension
         if ($request->getVar('SubsiteID') !== null) {
             // Clear current page when subsite changes (or is set for the first time)
             if ($state->getSessionWasChanged()) {
-                $session->clear($this->owner->sessionNamespace() . '.currentPage');
+                // sessionNamespace() is protected - see for info
+                $override = $this->owner->config()->get('session_namespace');
+                $sessionNamespace = $override ? $override : get_class($this->owner);
+                $session->clear($sessionNamespace . '.currentPage');
             }
 
             // Subsite ID has already been set to the state via InitStateMiddleware
             if ($this->owner->canView()) {
-                // Redirect to clear the current page
+                // Redirect to clear the current page, retaining the current URL parameters
-                return $this->owner->redirect($this->owner->Link());
+                return $this->owner->redirect(
+                    Controller::join_links($this->owner->Link(), ...array_values($this->owner->getURLParams()))
+                );
             }
             // Redirect to the default CMS section
             return $this->owner->redirect(AdminRootController::config()->get('url_base') . '/');
@@ -304,7 +309,7 @@ class LeftAndMainSubsites extends LeftAndMainExtension
             if ($canViewElsewhere) {
                 // Redirect to clear the current page
                 return $this->owner->redirect(
-                    Controller::join_links($this->owner->Link(), $record->ID, '?SubsiteID=' . $record->SubsiteID)
+                    Controller::join_links($this->owner->Link('show'), $record->ID, '?SubsiteID=' . $record->SubsiteID)
                 );
             }
             // Redirect to the default CMS section

tests/php/SubsiteAdminFunctionalTest.php

@@ -85,7 +85,7 @@ class SubsiteAdminFunctionalTest extends FunctionalTest
 
         $this->assertEquals(302, $response->getStatusCode());
         $this->assertContains(
-            'admin/pages/edit/' . $subsite1Home->ID . '?SubsiteID=' . $subsite1Home->SubsiteID,
+            'admin/pages/edit/show/' . $subsite1Home->ID . '?SubsiteID=' . $subsite1Home->SubsiteID,
             $response->getHeader('Location')
         );
 
@@ -95,7 +95,7 @@ class SubsiteAdminFunctionalTest extends FunctionalTest
         $response = $this->get("admin/pages/edit/show/$subsite1Home->ID");
         $this->assertEquals(302, $response->getStatusCode());
         $this->assertContains(
-            'admin/pages/edit/' . $subsite1Home->ID . '?SubsiteID=' . $subsite1Home->SubsiteID,
+            'admin/pages/edit/show/' . $subsite1Home->ID . '?SubsiteID=' . $subsite1Home->SubsiteID,
             $response->getHeader('Location')
         );