improved debugger on handling unreadable files

docs/guide/tool-debugger.md

@@ -19,6 +19,7 @@ Out of the box these tools allow you to:
 
 All of this information will be available per request, allowing you to revisit the information for past requests as well.
 
+
 Installing and configuring
 --------------------------
 
@@ -31,7 +32,8 @@ To enable these features, add these lines to your configuration file to enable t
 ]
 ```
 
-By default, the debug module only works when browsing the website from localhost. If you want to use it on a remote (staging) server, add the parameter `allowedIPs` to the configuration to whitelist your IP:
+By default, the debug module only works when browsing the website from localhost. If you want to use it on a remote (staging)
+server, add the parameter `allowedIPs` to the configuration to whitelist your IP:
 
 ```php
 'bootstrap' => ['debug'],
@@ -55,6 +57,11 @@ If you are using `enableStrictParsing` URL manager option, add the following to
 ],
 ```
 
+> Note: the debugger stores information about each request in the `@runtime/debug` directory. If you have problems using
+> The debugger such as weird error messages when using it or the toolbar not showing up or not showing any requests, check
+> whether the web server has enough permissions to access this directory and the files located inside.
+
+
 ### Extra configuration for logging and profiling
 
 Logging and profiling are simple but powerful tools that may help you to understand the execution flow of both the
@@ -84,6 +91,7 @@ defined('YII_DEBUG') or define('YII_DEBUG', true);
 
 > Note: Make sure to disable debug mode in production environments since it may have a significant and adverse performance effect. Further, the debug mode may expose sensitive information to end users.
 
+
 Creating your own panels
 ------------------------
 

extensions/debug/Module.php

@@ -61,6 +61,7 @@ class Module extends \yii\base\Module implements BootstrapInterface
      */
     public $enableDebugLogs = false;
 
+
     /**
      * Returns Yii logo ready to use in `<img src="`
      *

extensions/debug/controllers/DefaultController.php

@@ -116,7 +116,7 @@ class DefaultController extends Controller
                 clearstatcache();
             }
             $indexFile = $this->module->dataPath . '/index.data';
-            if (is_file($indexFile)) {
+            if (is_file($indexFile) && is_readable($indexFile)) {
                 $this->_manifest = array_reverse(unserialize(file_get_contents($indexFile)), true);
             } else {
                 $this->_manifest = [];

framework/db/QueryBuilder.php

@@ -576,7 +576,7 @@ class QueryBuilder extends \yii\base\Object
      * For example, 'string NOT NULL' is converted to 'varchar(255) NOT NULL'.
      *
      * For some of the abstract types you can also specify a length or precision constraint
-     * by prepending it in round brackets directly to the type.
+     * by appending it in round brackets directly to the type.
      * For example `string(32)` will be converted into "varchar(32)" on a MySQL database.
      * If the underlying DBMS does not support these kind of constraints for a type it will
      * be ignored.