From 3c35d25a646d187c40878e40fbf558922e4dd9ae Mon Sep 17 00:00:00 2001
From: Sam Minnee <sam@silverstripe.com>
Date: Mon, 26 Jun 2017 11:27:34 +1200
Subject: [PATCH] FIX: Allow DB::setConfig() in _config.php
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This wasn’t working because the database was being validated before
_config.php was loaed.

This is how the installer sets config so this is an important fix.
---
 src/Core/CoreKernel.php | 65 +++++++++++++++++++++++++++++++----------
 1 file changed, 49 insertions(+), 16 deletions(-)

diff --git a/src/Core/CoreKernel.php b/src/Core/CoreKernel.php
index df3339b18..f1842e453 100644
--- a/src/Core/CoreKernel.php
+++ b/src/Core/CoreKernel.php
@@ -185,8 +185,10 @@ class CoreKernel implements Kernel
         $this->bootPHP();
         $this->bootManifests($flush);
         $this->bootErrorHandling();
-        $this->bootDatabase();
+        $this->bootDatabaseEnvVars();
         $this->bootConfigs();
+        $this->bootDatabaseGlobals();
+        $this->validateDatabase();
     }
 
     /**
@@ -199,27 +201,63 @@ class CoreKernel implements Kernel
     }
 
     /**
-     * Configure database
-     *
-     * @throws HTTPResponse_Exception
+     * Load default database configuration from the $database and $databaseConfig globals
      */
-    protected function bootDatabase()
+    protected function bootDatabaseGlobals()
     {
-        // Check if a DB is named
-        $name = $this->getDatabaseName();
+        // Now that configs have been loaded, we can check global for database config
+        global $databaseConfig;
+        global $database;
 
-        // Gracefully fail if no DB is configured
-        if (empty($name)) {
-            $this->detectLegacyEnvironment();
-            $this->redirectToInstaller();
+        $prefix = getenv('SS_DATABASE_PREFIX') ?: 'SS_';
+
+        // Case 1: $databaseConfig global exists. Merge $database in as needed
+        if (!empty($databaseConfig)) {
+            if (!empty($database)) {
+                $databaseConfig['database'] = $prefix . $database;
+            }
+
+            // Only set it if its valid, otherwise ignore $databaseConfig entirely
+            if (!empty($databaseConfig['database'])) {
+                DB::setConfig($databaseConfig);
+                return;
+            }
         }
 
+        // Case 2: $database merged into existing config
+        if (!empty($database)) {
+            $existing = DB::getConfig();
+            $existing['database'] = $prefix . $database;
+            DB::setConfig($existing);
+        }
+    }
+
+    /**
+     * Load default database configuration from environment variable
+     */
+    protected function bootDatabaseEnvVars()
+    {
         // Set default database config
         $databaseConfig = $this->getDatabaseConfig();
         $databaseConfig['database'] = $this->getDatabaseName();
         DB::setConfig($databaseConfig);
     }
 
+    /**
+     * Check that the database configuration is valid, throwing an HTTPResponse_Exception if it's not
+     *
+     * @throws HTTPResponse_Exception
+     */
+    protected function validateDatabase()
+    {
+        $databaseConfig = DB::getConfig();
+        // Gracefully fail if no DB is configured
+        if (empty($databaseConfig['database'])) {
+            $this->detectLegacyEnvironment();
+            $this->redirectToInstaller();
+        }
+    }
+
     /**
      * Check if there's a legacy _ss_environment.php file
      *
@@ -280,11 +318,6 @@ class CoreKernel implements Kernel
      */
     protected function getDatabaseConfig()
     {
-        // Check global config
-        global $databaseConfig;
-        if (!empty($databaseConfig)) {
-            return $databaseConfig;
-        }
 
         /** @skipUpgrade */
         $databaseConfig = [