bug #33970 [String] wrap(): test and fix (gharlan)

This PR was merged into the 5.0-dev branch.

Discussion
----------

[String] wrap(): test and fix

| Q             | A
| ------------- | ---
| Branch?       | master
| Bug fix?      | yes
| New feature?  | no
| Deprecations? | no
| Tickets       | n/a
| License       | MIT
| Doc PR        | symfony/symfony-docs/pull/12440

Commits
-------

015b81a2f5 [String] wrap(): test and fix

Author: nicolas-grekas

AbstractString.php

@@ -75,18 +75,18 @@ public static function wrap(array $values): array
         $keys = null;
 
         foreach ($values as $k => $v) {
-            ++$i;
-
             if (\is_string($k) && '' !== $k && $k !== $j = (string) new static($k)) {
                 $keys = $keys ?? array_keys($values);
-                array_splice($keys, $i, 1, [$j]);
+                $keys[$i] = $j;
             }
 
             if (\is_string($v)) {
                 $values[$k] = new static($v);
             } elseif (\is_array($v) && $values[$k] !== $v = static::wrap($v)) {
                 $values[$k] = $v;
             }
+
+            ++$i;
         }
 
         return null !== $keys ? array_combine($keys, $values) : $values;

Tests/AbstractAsciiTestCase.php

@@ -34,6 +34,31 @@ public function testCreateFromEmptyString()
         $this->assertTrue($instance->isEmpty());
     }
 
+    /**
+     * @dataProvider provideWrap
+     */
+    public function testWrap(array $expected, array $values)
+    {
+        $s = static::createFromString('');
+
+        $this->assertEquals($expected, $s::wrap($values));
+    }
+
+    public static function provideWrap(): array
+    {
+        return [
+            [[], []],
+            [
+                ['abc' => static::createFromString('foo'), 1, static::createFromString('bar'), 'baz' => true],
+                ['abc' => 'foo', 1, 'bar', 'baz' => true],
+            ],
+            [
+                ['a' => ['b' => static::createFromString('c'), [static::createFromString('d')]], static::createFromString('e')],
+                ['a' => ['b' => 'c', ['d']], 'e'],
+            ],
+        ];
+    }
+
     /**
      * @dataProvider provideLength
      */

Tests/UnicodeStringTest.php

@@ -21,6 +21,23 @@ protected static function createFromString(string $string): AbstractString
         return new UnicodeString($string);
     }
 
+    public static function provideWrap(): array
+    {
+        return array_merge(
+            parent::provideWrap(),
+            [
+                [
+                    ['Käse' => static::createFromString('köstlich'), 'fromage' => static::createFromString('délicieux')],
+                    ["Ka\u{0308}se" => "ko\u{0308}stlich", 'fromage' => 'délicieux'],
+                ],
+                [
+                    ['a' => 1, 'ä' => ['ö' => 2, 'ü' => 3]],
+                    ['a' => 1, "a\u{0308}" => ["o\u{0308}" => 2, 'ü' => 3]],
+                ],
+            ]
+        );
+    }
+
     public static function provideLength(): array
     {
         return array_merge(