diff --git a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
index 52369bbffa..4dfbb0b82d 100644
--- a/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
+++ b/src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php
@@ -264,7 +264,7 @@ class Configuration implements ConfigurationInterface
                     ->canBeEnabled()
                     ->beforeNormalization()
                         ->always(function ($v) {
-                            if (true === $v['enabled']) {
+                            if (\is_array($v) && true === $v['enabled']) {
                                 $workflows = $v;
                                 unset($workflows['enabled']);
 
diff --git a/src/Symfony/Component/Config/Util/XmlUtils.php b/src/Symfony/Component/Config/Util/XmlUtils.php
index df1edd68bd..dfacaff4ea 100644
--- a/src/Symfony/Component/Config/Util/XmlUtils.php
+++ b/src/Symfony/Component/Config/Util/XmlUtils.php
@@ -234,7 +234,7 @@ class XmlUtils
                 return true;
             case 'false' === $lowercaseValue:
                 return false;
-            case isset($value[1]) && '0b' == $value[0].$value[1]:
+            case isset($value[1]) && '0b' == $value[0].$value[1] && preg_match('/^0b[01]*$/', $value):
                 return bindec($value);
             case is_numeric($value):
                 return '0x' === $value[0].$value[1] ? hexdec($value) : (float) $value;
diff --git a/src/Symfony/Component/Debug/ErrorHandler.php b/src/Symfony/Component/Debug/ErrorHandler.php
index c7dc3279d7..9d7c0c67ad 100644
--- a/src/Symfony/Component/Debug/ErrorHandler.php
+++ b/src/Symfony/Component/Debug/ErrorHandler.php
@@ -470,7 +470,7 @@ class ErrorHandler
         }
 
         if ($throw) {
-            if (E_USER_ERROR & $type) {
+            if (\PHP_VERSION_ID < 70400 && E_USER_ERROR & $type) {
                 for ($i = 1; isset($backtrace[$i]); ++$i) {
                     if (isset($backtrace[$i]['function'], $backtrace[$i]['type'], $backtrace[$i - 1]['function'])
                         && '__toString' === $backtrace[$i]['function']
diff --git a/src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php b/src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php
index 3094d22d95..2cf75a0e8e 100644
--- a/src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php
+++ b/src/Symfony/Component/Debug/Tests/ErrorHandlerTest.php
@@ -283,6 +283,10 @@ class ErrorHandlerTest extends TestCase
 
     public function testHandleUserError()
     {
+        if (\PHP_VERSION_ID >= 70400) {
+            $this->markTestSkipped('PHP 7.4 allows __toString to throw exceptions');
+        }
+
         try {
             $handler = ErrorHandler::register();
             $handler->throwAt(0, true);
diff --git a/src/Symfony/Component/DomCrawler/FormFieldRegistry.php b/src/Symfony/Component/DomCrawler/FormFieldRegistry.php
index 8f432cfbbb..bd73742af7 100644
--- a/src/Symfony/Component/DomCrawler/FormFieldRegistry.php
+++ b/src/Symfony/Component/DomCrawler/FormFieldRegistry.php
@@ -57,7 +57,7 @@ class FormFieldRegistry
         $target = &$this->fields;
         while (\count($segments) > 1) {
             $path = array_shift($segments);
-            if (!\array_key_exists($path, $target)) {
+            if (!\is_array($target) || !\array_key_exists($path, $target)) {
                 return;
             }
             $target = &$target[$path];
@@ -80,7 +80,7 @@ class FormFieldRegistry
         $target = &$this->fields;
         while ($segments) {
             $path = array_shift($segments);
-            if (!\array_key_exists($path, $target)) {
+            if (!\is_array($target) || !\array_key_exists($path, $target)) {
                 throw new \InvalidArgumentException(sprintf('Unreachable field "%s"', $path));
             }
             $target = &$target[$path];
diff --git a/src/Symfony/Component/Finder/Tests/Iterator/SortableIteratorTest.php b/src/Symfony/Component/Finder/Tests/Iterator/SortableIteratorTest.php
index 57f1e096a5..118c4769f2 100644
--- a/src/Symfony/Component/Finder/Tests/Iterator/SortableIteratorTest.php
+++ b/src/Symfony/Component/Finder/Tests/Iterator/SortableIteratorTest.php
@@ -33,11 +33,7 @@ class SortableIteratorTest extends RealIteratorTestCase
         if (!\is_callable($mode)) {
             switch ($mode) {
                 case SortableIterator::SORT_BY_ACCESSED_TIME:
-                    if ('\\' === \DIRECTORY_SEPARATOR) {
-                        touch(self::toAbsolute('.git'));
-                    } else {
-                        file_get_contents(self::toAbsolute('.git'));
-                    }
+                    touch(self::toAbsolute('.git'));
                     sleep(1);
                     file_get_contents(self::toAbsolute('.bar'));
                     break;
diff --git a/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php b/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
index 91e6ff5f8e..96c74fe0e4 100644
--- a/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
+++ b/src/Symfony/Component/Form/Tests/Extension/Core/Type/DateTypeTest.php
@@ -471,6 +471,7 @@ class DateTypeTest extends BaseTypeTest
 
     public function testMonthsOption()
     {
+        \Locale::setDefault('en');
         $form = $this->factory->create(static::TESTED_TYPE, null, [
             'months' => [6, 7],
             'format' => \IntlDateFormatter::SHORT,
@@ -479,8 +480,8 @@ class DateTypeTest extends BaseTypeTest
         $view = $form->createView();
 
         $this->assertEquals([
-            new ChoiceView(6, '6', '06'),
-            new ChoiceView(7, '7', '07'),
+            new ChoiceView(6, '6', '6'),
+            new ChoiceView(7, '7', '7'),
         ], $view['month']->vars['choices']);
     }
 
@@ -544,14 +545,15 @@ class DateTypeTest extends BaseTypeTest
 
     public function testIsDayWithinRangeReturnsTrueIfWithin()
     {
+        \Locale::setDefault('en');
         $view = $this->factory->create(static::TESTED_TYPE, null, [
             'days' => [6, 7],
         ])
             ->createView();
 
         $this->assertEquals([
-            new ChoiceView(6, '6', '06'),
-            new ChoiceView(7, '7', '07'),
+            new ChoiceView(6, '6', '6'),
+            new ChoiceView(7, '7', '7'),
         ], $view['day']->vars['choices']);
     }
 
diff --git a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractCurrencyDataProviderTest.php b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractCurrencyDataProviderTest.php
index 3b1f4957aa..12660eb0ac 100644
--- a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractCurrencyDataProviderTest.php
+++ b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractCurrencyDataProviderTest.php
@@ -589,6 +589,7 @@ abstract class AbstractCurrencyDataProviderTest extends AbstractDataProviderTest
      * @var CurrencyDataProvider
      */
     protected $dataProvider;
+    private $defaultLocale;
 
     protected function setUp()
     {
@@ -598,6 +599,15 @@ abstract class AbstractCurrencyDataProviderTest extends AbstractDataProviderTest
             $this->getDataDirectory().'/'.Intl::CURRENCY_DIR,
             $this->createEntryReader()
         );
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
     }
 
     abstract protected function getDataDirectory();
diff --git a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLanguageDataProviderTest.php b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLanguageDataProviderTest.php
index 917f6f0dd1..2d294f2c64 100644
--- a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLanguageDataProviderTest.php
+++ b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLanguageDataProviderTest.php
@@ -831,6 +831,7 @@ abstract class AbstractLanguageDataProviderTest extends AbstractDataProviderTest
      * @var LanguageDataProvider
      */
     protected $dataProvider;
+    private $defaultLocale;
 
     protected function setUp()
     {
@@ -840,6 +841,15 @@ abstract class AbstractLanguageDataProviderTest extends AbstractDataProviderTest
             $this->getDataDirectory().'/'.Intl::LANGUAGE_DIR,
             $this->createEntryReader()
         );
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
     }
 
     abstract protected function getDataDirectory();
diff --git a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLocaleDataProviderTest.php b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLocaleDataProviderTest.php
index 88242a6f9b..7da43c70eb 100644
--- a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLocaleDataProviderTest.php
+++ b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractLocaleDataProviderTest.php
@@ -23,6 +23,7 @@ abstract class AbstractLocaleDataProviderTest extends AbstractDataProviderTest
      * @var LocaleDataProvider
      */
     protected $dataProvider;
+    private $defaultLocale;
 
     protected function setUp()
     {
@@ -32,6 +33,13 @@ abstract class AbstractLocaleDataProviderTest extends AbstractDataProviderTest
             $this->getDataDirectory().'/'.Intl::LOCALE_DIR,
             $this->createEntryReader()
         );
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        \Locale::setDefault($this->defaultLocale);
     }
 
     abstract protected function getDataDirectory();
diff --git a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractRegionDataProviderTest.php b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractRegionDataProviderTest.php
index aeb922f9e3..6e2f57aa7a 100644
--- a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractRegionDataProviderTest.php
+++ b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractRegionDataProviderTest.php
@@ -283,6 +283,7 @@ abstract class AbstractRegionDataProviderTest extends AbstractDataProviderTest
      * @var RegionDataProvider
      */
     protected $dataProvider;
+    private $defaultLocale;
 
     protected function setUp()
     {
@@ -292,6 +293,15 @@ abstract class AbstractRegionDataProviderTest extends AbstractDataProviderTest
             $this->getDataDirectory().'/'.Intl::REGION_DIR,
             $this->createEntryReader()
         );
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
     }
 
     abstract protected function getDataDirectory();
diff --git a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractScriptDataProviderTest.php b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractScriptDataProviderTest.php
index 8620fb2060..5c279065a1 100644
--- a/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractScriptDataProviderTest.php
+++ b/src/Symfony/Component/Intl/Tests/Data/Provider/AbstractScriptDataProviderTest.php
@@ -219,6 +219,7 @@ abstract class AbstractScriptDataProviderTest extends AbstractDataProviderTest
      * @var ScriptDataProvider
      */
     protected $dataProvider;
+    private $defaultLocale;
 
     protected function setUp()
     {
@@ -228,6 +229,15 @@ abstract class AbstractScriptDataProviderTest extends AbstractDataProviderTest
             $this->getDataDirectory().'/'.Intl::SCRIPT_DIR,
             $this->createEntryReader()
         );
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
     }
 
     abstract protected function getDataDirectory();
diff --git a/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php b/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php
index 682380bf54..df99b12109 100644
--- a/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php
+++ b/src/Symfony/Component/Intl/Tests/DateFormatter/AbstractIntlDateFormatterTest.php
@@ -24,11 +24,23 @@ use Symfony\Component\Intl\Util\IcuVersion;
  */
 abstract class AbstractIntlDateFormatterTest extends TestCase
 {
+    private $defaultLocale;
+
     protected function setUp()
     {
+        parent::setUp();
+
+        $this->defaultLocale = \Locale::getDefault();
         \Locale::setDefault('en');
     }
 
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
+    }
+
     /**
      * When a time zone is not specified, it uses the system default however it returns null in the getter method.
      *
diff --git a/src/Symfony/Component/Intl/Tests/IntlTest.php b/src/Symfony/Component/Intl/Tests/IntlTest.php
index d45a1ded5c..059f5eb6c4 100644
--- a/src/Symfony/Component/Intl/Tests/IntlTest.php
+++ b/src/Symfony/Component/Intl/Tests/IntlTest.php
@@ -16,6 +16,22 @@ use Symfony\Component\Intl\Intl;
 
 class IntlTest extends TestCase
 {
+    private $defaultLocale;
+
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
+    }
+
     /**
      * @requires extension intl
      */
diff --git a/src/Symfony/Component/Intl/Tests/NumberFormatter/AbstractNumberFormatterTest.php b/src/Symfony/Component/Intl/Tests/NumberFormatter/AbstractNumberFormatterTest.php
index 9e8499eba9..f64131a61b 100644
--- a/src/Symfony/Component/Intl/Tests/NumberFormatter/AbstractNumberFormatterTest.php
+++ b/src/Symfony/Component/Intl/Tests/NumberFormatter/AbstractNumberFormatterTest.php
@@ -36,7 +36,7 @@ abstract class AbstractNumberFormatterTest extends TestCase
     {
         return [
             [100, 'ALL', '100'],
-            [100, 'BRL', '100.00'],
+            [100, 'BRL', '100'],
             [100, 'CRC', '100'],
             [100, 'JPY', '100'],
             [100, 'CHF', '100'],
diff --git a/src/Symfony/Component/Stopwatch/Tests/StopwatchTest.php b/src/Symfony/Component/Stopwatch/Tests/StopwatchTest.php
index f85ccd0ec4..b8efa373b4 100644
--- a/src/Symfony/Component/Stopwatch/Tests/StopwatchTest.php
+++ b/src/Symfony/Component/Stopwatch/Tests/StopwatchTest.php
@@ -87,7 +87,7 @@ class StopwatchTest extends TestCase
         $event = $stopwatch->stop('foo');
 
         $this->assertInstanceOf('Symfony\Component\Stopwatch\StopwatchEvent', $event);
-        $this->assertEquals(200, $event->getDuration(), '', self::DELTA);
+        $this->assertEqualsWithDelta(200, $event->getDuration(), self::DELTA);
     }
 
     public function testUnknownEvent()
diff --git a/src/Symfony/Component/Translation/Loader/CsvFileLoader.php b/src/Symfony/Component/Translation/Loader/CsvFileLoader.php
index 18cc83ed68..db17bd5631 100644
--- a/src/Symfony/Component/Translation/Loader/CsvFileLoader.php
+++ b/src/Symfony/Component/Translation/Loader/CsvFileLoader.php
@@ -41,6 +41,10 @@ class CsvFileLoader extends FileLoader
         $file->setCsvControl($this->delimiter, $this->enclosure, $this->escape);
 
         foreach ($file as $data) {
+            if (false === $data) {
+                continue;
+            }
+
             if ('#' !== substr($data[0], 0, 1) && isset($data[1]) && 2 === \count($data)) {
                 $messages[$data[0]] = $data[1];
             }
diff --git a/src/Symfony/Component/Translation/Tests/IdentityTranslatorTest.php b/src/Symfony/Component/Translation/Tests/IdentityTranslatorTest.php
index c3d7b1f7d1..a5c63df988 100644
--- a/src/Symfony/Component/Translation/Tests/IdentityTranslatorTest.php
+++ b/src/Symfony/Component/Translation/Tests/IdentityTranslatorTest.php
@@ -17,6 +17,22 @@ use Symfony\Component\Translation\IdentityTranslator;
 
 class IdentityTranslatorTest extends TestCase
 {
+    private $defaultLocale;
+
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
+    }
+
     /**
      * @dataProvider getTransTests
      */
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/CountryValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/CountryValidatorTest.php
index 429aef812f..f5cb9a6db3 100644
--- a/src/Symfony/Component/Validator/Tests/Constraints/CountryValidatorTest.php
+++ b/src/Symfony/Component/Validator/Tests/Constraints/CountryValidatorTest.php
@@ -18,6 +18,22 @@ use Symfony\Component\Validator\Test\ConstraintValidatorTestCase;
 
 class CountryValidatorTest extends ConstraintValidatorTestCase
 {
+    private $defaultLocale;
+
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
+    }
+
     protected function createValidator()
     {
         return new CountryValidator();
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/CurrencyValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/CurrencyValidatorTest.php
index 7a61973536..d46fcd5548 100644
--- a/src/Symfony/Component/Validator/Tests/Constraints/CurrencyValidatorTest.php
+++ b/src/Symfony/Component/Validator/Tests/Constraints/CurrencyValidatorTest.php
@@ -18,6 +18,22 @@ use Symfony\Component\Validator\Test\ConstraintValidatorTestCase;
 
 class CurrencyValidatorTest extends ConstraintValidatorTestCase
 {
+    private $defaultLocale;
+
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
+    }
+
     protected function createValidator()
     {
         return new CurrencyValidator();
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/LanguageValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/LanguageValidatorTest.php
index f23fd13fcb..31a987bdd3 100644
--- a/src/Symfony/Component/Validator/Tests/Constraints/LanguageValidatorTest.php
+++ b/src/Symfony/Component/Validator/Tests/Constraints/LanguageValidatorTest.php
@@ -18,6 +18,22 @@ use Symfony\Component\Validator\Test\ConstraintValidatorTestCase;
 
 class LanguageValidatorTest extends ConstraintValidatorTestCase
 {
+    private $defaultLocale;
+
+    protected function setUp()
+    {
+        parent::setUp();
+
+        $this->defaultLocale = \Locale::getDefault();
+    }
+
+    protected function tearDown()
+    {
+        parent::tearDown();
+
+        \Locale::setDefault($this->defaultLocale);
+    }
+
     protected function createValidator()
     {
         return new LanguageValidator();
diff --git a/src/Symfony/Component/Validator/Tests/Constraints/RangeValidatorTest.php b/src/Symfony/Component/Validator/Tests/Constraints/RangeValidatorTest.php
index 661161d886..df33d2c422 100644
--- a/src/Symfony/Component/Validator/Tests/Constraints/RangeValidatorTest.php
+++ b/src/Symfony/Component/Validator/Tests/Constraints/RangeValidatorTest.php
@@ -50,7 +50,7 @@ class RangeValidatorTest extends ConstraintValidatorTestCase
             [9.99999, '9.99999'],
             ['9.99999', '"9.99999"'],
             [5, '5'],
-            [1.0, '1.0'],
+            [1.0, '1'],
         ];
     }
 
@@ -60,7 +60,7 @@ class RangeValidatorTest extends ConstraintValidatorTestCase
             [20.000001, '20.000001'],
             ['20.000001', '"20.000001"'],
             [21, '21'],
-            [30.0, '30.0'],
+            [30.0, '30'],
         ];
     }
 
diff --git a/src/Symfony/Component/VarDumper/Tests/Caster/ExceptionCasterTest.php b/src/Symfony/Component/VarDumper/Tests/Caster/ExceptionCasterTest.php
index ea83e77163..738180f5b2 100644
--- a/src/Symfony/Component/VarDumper/Tests/Caster/ExceptionCasterTest.php
+++ b/src/Symfony/Component/VarDumper/Tests/Caster/ExceptionCasterTest.php
@@ -52,7 +52,6 @@ Exception {
       › }
     }
     %s%eTests%eCaster%eExceptionCasterTest.php:40 { …}
-    Symfony\Component\VarDumper\Tests\Caster\ExceptionCasterTest->testDefaultSettings() {}
 %A
 EODUMP;
 
@@ -71,8 +70,7 @@ EODUMP;
     ›     return new \Exception(''.$msg);
     › }
   }
-  %s%eTests%eCaster%eExceptionCasterTest.php:65 { …}
-  Symfony\Component\VarDumper\Tests\Caster\ExceptionCasterTest->testSeek() {}
+  %s%eTests%eCaster%eExceptionCasterTest.php:64 { …}
 %A
 EODUMP;
 
@@ -96,8 +94,7 @@ Exception {
       ›     return new \Exception(''.$msg);
       › }
     }
-    %s%eTests%eCaster%eExceptionCasterTest.php:84 { …}
-    Symfony\Component\VarDumper\Tests\Caster\ExceptionCasterTest->testNoArgs() {}
+    %s%eTests%eCaster%eExceptionCasterTest.php:82 { …}
 %A
 EODUMP;