diff --git a/framework/console/ErrorHandler.php b/framework/console/ErrorHandler.php
index 16127a1..ddea40a 100644
--- a/framework/console/ErrorHandler.php
+++ b/framework/console/ErrorHandler.php
@@ -9,7 +9,6 @@ namespace yii\console;
 
 use Yii;
 use yii\base\ErrorException;
-use yii\base\UserException;
 use yii\helpers\Console;
 
 /**
@@ -39,7 +38,7 @@ class ErrorHandler extends \yii\base\ErrorHandler
             } elseif (count($alternatives) > 1) {
                 $message .= "\n\nDid you mean one of these?\n    - " . implode("\n    - ", $alternatives);
             }
-        } elseif ($exception instanceof Exception && ($exception instanceof UserException || !YII_DEBUG)) {
+        } elseif ($exception instanceof Exception || !YII_DEBUG) {
             $message = $this->formatMessage($exception->getName() . ': ') . $exception->getMessage();
         } elseif (YII_DEBUG) {
             if ($exception instanceof Exception) {
diff --git a/framework/data/DataFilter.php b/framework/data/DataFilter.php
index 6af8447..c07e2a8 100644
--- a/framework/data/DataFilter.php
+++ b/framework/data/DataFilter.php
@@ -355,7 +355,7 @@ class DataFilter extends Model
     /**
      * Detect attribute type from given validator.
      *
-     * @param Validator validator from which to detect attribute type.
+     * @param Validator $validator validator from which to detect attribute type.
      * @return string|null detected attribute type.
      * @since 2.0.14
      */
diff --git a/framework/db/SqlToken.php b/framework/db/SqlToken.php
index 0e947c1..fa57068 100644
--- a/framework/db/SqlToken.php
+++ b/framework/db/SqlToken.php
@@ -267,10 +267,8 @@ class SqlToken extends BaseObject implements \ArrayAccess
 
                 if ($firstMatchIndex === null) {
                     $firstMatchIndex = $offset;
-                    $lastMatchIndex = $offset;
-                } else {
-                    $lastMatchIndex = $offset;
                 }
+                $lastMatchIndex = $offset;
                 $wildcard = false;
                 $offset++;
                 continue 2;
diff --git a/framework/db/mssql/QueryBuilder.php b/framework/db/mssql/QueryBuilder.php
index 6b6c89c..79c5d3d 100644
--- a/framework/db/mssql/QueryBuilder.php
+++ b/framework/db/mssql/QueryBuilder.php
@@ -108,7 +108,7 @@ class QueryBuilder extends \yii\db\QueryBuilder
      * Builds the ORDER BY/LIMIT/OFFSET clauses for SQL SERVER 2005 to 2008.
      * @param string $sql the existing SQL (without ORDER BY/LIMIT/OFFSET)
      * @param array $orderBy the order by columns. See [[\yii\db\Query::orderBy]] for more details on how to specify this parameter.
-     * @param int $limit the limit number. See [[\yii\db\Query::limit]] for more details.
+     * @param int|Expression $limit the limit number. See [[\yii\db\Query::limit]] for more details.
      * @param int $offset the offset number. See [[\yii\db\Query::offset]] for more details.
      * @return string the SQL completed with ORDER BY/LIMIT/OFFSET (if any)
      */
diff --git a/framework/i18n/GettextMessageSource.php b/framework/i18n/GettextMessageSource.php
index 251bd7f..d96fb52 100644
--- a/framework/i18n/GettextMessageSource.php
+++ b/framework/i18n/GettextMessageSource.php
@@ -113,7 +113,7 @@ class GettextMessageSource extends MessageSource
         } elseif (!empty($fallbackMessages)) {
             foreach ($fallbackMessages as $key => $value) {
                 if (!empty($value) && empty($messages[$key])) {
-                    $messages[$key] = $fallbackMessages[$key];
+                    $messages[$key] = $value;
                 }
             }
         }
diff --git a/framework/i18n/PhpMessageSource.php b/framework/i18n/PhpMessageSource.php
index 9758468..4bcfcd9 100644
--- a/framework/i18n/PhpMessageSource.php
+++ b/framework/i18n/PhpMessageSource.php
@@ -115,7 +115,7 @@ class PhpMessageSource extends MessageSource
         } elseif (!empty($fallbackMessages)) {
             foreach ($fallbackMessages as $key => $value) {
                 if (!empty($value) && empty($messages[$key])) {
-                    $messages[$key] = $fallbackMessages[$key];
+                    $messages[$key] = $value;
                 }
             }
         }
diff --git a/framework/log/Target.php b/framework/log/Target.php
index 2a192e8..819669e 100644
--- a/framework/log/Target.php
+++ b/framework/log/Target.php
@@ -11,7 +11,6 @@ use Yii;
 use yii\base\Component;
 use yii\base\InvalidConfigException;
 use yii\helpers\ArrayHelper;
-use yii\helpers\StringHelper;
 use yii\helpers\VarDumper;
 use yii\web\Request;
 
diff --git a/framework/mutex/PgsqlMutex.php b/framework/mutex/PgsqlMutex.php
index 8c38c75..900ac5f 100644
--- a/framework/mutex/PgsqlMutex.php
+++ b/framework/mutex/PgsqlMutex.php
@@ -7,7 +7,6 @@
 
 namespace yii\mutex;
 
-use yii\base\InvalidArgumentException;
 use yii\base\InvalidConfigException;
 
 /**
diff --git a/framework/requirements/views/console/index.php b/framework/requirements/views/console/index.php
index d1559b6..68c4cb5 100644
--- a/framework/requirements/views/console/index.php
+++ b/framework/requirements/views/console/index.php
@@ -23,7 +23,6 @@ echo str_pad('', strlen($header), '-') . "\n\n";
 foreach ($requirements as $key => $requirement) {
     if ($requirement['condition']) {
         echo $requirement['name'] . ": OK\n";
-        echo "\n";
     } else {
         echo $requirement['name'] . ': ' . ($requirement['mandatory'] ? 'FAILED!!!' : 'WARNING!!!') . "\n";
         echo 'Required by: ' . strip_tags($requirement['by']) . "\n";
@@ -31,8 +30,8 @@ foreach ($requirements as $key => $requirement) {
         if (!empty($memo)) {
             echo 'Memo: ' . strip_tags($requirement['memo']) . "\n";
         }
-        echo "\n";
     }
+    echo "\n";
 }
 
 $summaryString = 'Errors: ' . $summary['errors'] . '   Warnings: ' . $summary['warnings'] . '   Total checks: ' . $summary['total'];
diff --git a/framework/widgets/MaskedInput.php b/framework/widgets/MaskedInput.php
index 6c02f1d..632af1f 100644
--- a/framework/widgets/MaskedInput.php
+++ b/framework/widgets/MaskedInput.php
@@ -8,7 +8,6 @@
 namespace yii\widgets;
 
 use yii\base\InvalidConfigException;
-use yii\helpers\Html;
 use yii\helpers\Json;
 use yii\web\JsExpression;
 use yii\web\View;