Merge branch '3.4' into 4.3

* 3.4:
  #30432 fix an error message
  fix paths to detect code owners
  [Validator] Ensure numeric subpaths do not cause errors on PHP 7.4
  Remove unused local variables in tests
  Make sure to collect child forms created on *_SET_DATA events
  do not render errors for checkboxes twice

Author: nicolas-grekas

Tests/ExpressionLanguageTest.php

@@ -63,6 +63,14 @@ public function testCachedParse()
         $this->assertSame($savedParsedExpression, $parsedExpression);
     }
 
+    public function testWrongCacheImplementation()
+    {
+        $this->expectException('InvalidArgumentException');
+        $this->expectExceptionMessage('Cache argument has to implement Psr\Cache\CacheItemPoolInterface.');
+        $cacheMock = $this->getMockBuilder('Psr\Cache\CacheItemSpoolInterface')->getMock();
+        new ExpressionLanguage($cacheMock);
+    }
+
     public function testConstantFunction()
     {
         $expressionLanguage = new ExpressionLanguage();
@@ -158,7 +166,7 @@ public function testCachingWithDifferentNamesOrder()
         $cacheMock = $this->getMockBuilder('Psr\Cache\CacheItemPoolInterface')->getMock();
         $cacheItemMock = $this->getMockBuilder('Psr\Cache\CacheItemInterface')->getMock();
         $expressionLanguage = new ExpressionLanguage($cacheMock);
-        $savedParsedExpressions = [];
+        $savedParsedExpression = null;
 
         $cacheMock
             ->expects($this->exactly(2))