From c5f8d7df20cfaea7e2189795e188bb78a51fc4d1 Mon Sep 17 00:00:00 2001
From: Anton <info@ensostudio.ru>
Date: Sat, 7 Aug 2021 17:54:10 +0300
Subject: [PATCH] Fix #18807: Fix replacing source whitespaces and optimize
 code of `yii\helpers\BaseStringHelper::mb_ucwords()`

---
 framework/CHANGELOG.md                       |  1 +
 framework/helpers/BaseStringHelper.php       | 20 ++++++++++++++------
 tests/framework/helpers/StringHelperTest.php |  5 +++++
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/framework/CHANGELOG.md b/framework/CHANGELOG.md
index 81d11b4d04..a1b8cadc88 100644
--- a/framework/CHANGELOG.md
+++ b/framework/CHANGELOG.md
@@ -24,6 +24,7 @@ Yii Framework 2 Change Log
 - Enh #18274: Added `profilingAware` option to `yii\log\Logger` to prevent breaking the profiling block messages pair when flushing them (bizley)
 - Enh #18789: Added JSONP support in `yii\web\JsonParser::parse()` (WinterSilence)
 - Bug #18274: Fix `yii\log\Logger` to calculate profile timings no matter the value of the flush interval (bizley)
+- Bug #18807: Fix replacing source whitespaces and optimize code of `yii\helpers\BaseStringHelper::mb_ucwords()` (WinterSilence)
 
 
 2.0.42.1 May 06, 2021
diff --git a/framework/helpers/BaseStringHelper.php b/framework/helpers/BaseStringHelper.php
index 48a12e6422..8ab4db035d 100644
--- a/framework/helpers/BaseStringHelper.php
+++ b/framework/helpers/BaseStringHelper.php
@@ -457,17 +457,25 @@ class BaseStringHelper
      * @param string $string the string to be proceeded
      * @param string $encoding Optional, defaults to "UTF-8"
      * @return string
-     * @see https://secure.php.net/manual/en/function.ucwords.php
+     * @see https://www.php.net/manual/en/function.ucwords
      * @since 2.0.16
      */
     public static function mb_ucwords($string, $encoding = 'UTF-8')
     {
-        $words = preg_split("/\s/u", $string, -1, PREG_SPLIT_NO_EMPTY);
+        $string = (string) $string;
+        if (empty($string)) {
+            return $string;
+        }
 
-        $titelized = array_map(function ($word) use ($encoding) {
-            return static::mb_ucfirst($word, $encoding);
-        }, $words);
+        $parts = preg_split('/(\s+[^\w]+\s+|^[^\w]+\s+|\s+)/u', $string, -1, PREG_SPLIT_NO_EMPTY | PREG_SPLIT_DELIM_CAPTURE);
+        $ucfirstEven = !trim(mb_substr($parts[0], -1, 1, $encoding));
+        foreach ($parts as $key => $value) {
+            $isEven = (bool)($key % 2);
+            if ($ucfirstEven === $isEven) {
+                $parts[$key] = static::mb_ucfirst($value, $encoding);
+            }
+        }
 
-        return implode(' ', $titelized);
+        return implode('', $parts);
     }
 }
diff --git a/tests/framework/helpers/StringHelperTest.php b/tests/framework/helpers/StringHelperTest.php
index 90dc42e08e..faac9bf6f9 100644
--- a/tests/framework/helpers/StringHelperTest.php
+++ b/tests/framework/helpers/StringHelperTest.php
@@ -429,8 +429,13 @@ class StringHelperTest extends TestCase
         return [
             ['foo', 'Foo'],
             ['foo bar', 'Foo Bar'],
+            ['!foo bar-baz', '!foo Bar-baz'],
+            [' foo BAR', ' Foo BAR'],
+            [' ! foo BAR', ' ! Foo BAR'],
+            ["\tfoo\nbar  baz", "\tFoo\nBar  Baz"],
             ['👍🏻 foo bar', '👍🏻 Foo Bar'],
             ['', ''],
+            ['0', '0'],
             [null, ''],
             ['здесь我 multibyte我 строка', 'Здесь我 Multibyte我 Строка'],
         ];