Merge branch '3.0' into 3.1

* 3.0:
  `@throws` annotations should go after `@return`
  Fix merge
  updated VERSION for 2.3.42
  update CONTRIBUTORS for 2.3.42
  updated CHANGELOG for 2.3.42
  Revert "bug #18908 [DependencyInjection] force enabling the external XML entity loaders (xabbuh)"
  Partial revert of previous PR
  [DependencyInjection] Skip deep reference check for 'service_container'
  Catch \Throwable
  [Serializer] Add missing @throws annotations
  Fix for #18843
  force enabling the external XML entity loaders
  Removed UTC specification with timestamp

Conflicts:
	src/Symfony/Component/Yaml/Tests/InlineTest.php

Author: nicolas-grekas

Dumper.php

@@ -85,7 +85,7 @@ public function dump($input, $inline = 0, $indent = 0, $flags = 0)
         if ($inline <= 0 || !is_array($input) || empty($input)) {
             $output .= $prefix.Inline::dump($input, $flags);
         } else {
-            $isAHash = array_keys($input) !== range(0, count($input) - 1);
+            $isAHash = Inline::isHash($input);
 
             foreach ($input as $key => $value) {
                 if ($inline > 1 && Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK & $flags && is_string($value) && false !== strpos($value, "\n")) {

Inline.php

@@ -214,6 +214,28 @@ public static function dump($value, $flags = 0)
         }
     }
 
+    /**
+     * Check if given array is hash or just normal indexed array.
+     *
+     * @internal
+     *
+     * @param array $value The PHP array to check
+     *
+     * @return bool true if value is hash array, false otherwise
+     */
+    public static function isHash(array $value)
+    {
+        $expectedKey = 0;
+
+        foreach ($value as $key => $val) {
+            if ($key !== $expectedKey++) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     /**
      * Dumps a PHP array to a YAML string.
      *
@@ -225,11 +247,7 @@ public static function dump($value, $flags = 0)
     private static function dumpArray($value, $flags)
     {
         // array
-        $keys = array_keys($value);
-        $keysCount = count($keys);
-        if ((1 === $keysCount && '0' == $keys[0])
-            || ($keysCount > 1 && array_reduce($keys, function ($v, $w) { return (int) $v + $w; }, 0) === $keysCount * ($keysCount - 1) / 2)
-        ) {
+        if ($value && !self::isHash($value)) {
             $output = array();
             foreach ($value as $val) {
                 $output[] = self::dump($val, $flags);
@@ -238,7 +256,7 @@ private static function dumpArray($value, $flags)
             return sprintf('[%s]', implode(', ', $output));
         }
 
-        // mapping
+        // hash
         $output = array();
         foreach ($value as $key => $val) {
             $output[] = sprintf('%s: %s', self::dump($key, $flags), self::dump($val, $flags));

Tests/InlineTest.php

@@ -277,6 +277,24 @@ public function testParseUnquotedScalarStartingWithPercentCharacter()
         $this->assertContains('Not quoting a scalar starting with the "%" indicator character is deprecated since Symfony 3.1 and will throw a ParseException in 4.0.', $deprecations[0]);
     }
 
+    /**
+     * @dataProvider getDataForIsHash
+     */
+    public function testIsHash($array, $expected)
+    {
+        $this->assertSame($expected, Inline::isHash($array));
+    }
+
+    public function getDataForIsHash()
+    {
+        return array(
+            array(array(), false),
+            array(array(1, 2, 3), false),
+            array(array(2 => 1, 1 => 2, 0 => 3), true),
+            array(array('foo' => 1, 'bar' => 2), true),
+        );
+    }
+
     public function getTestsForParse()
     {
         return array(
@@ -483,6 +501,8 @@ public function getTestsForDump()
             array('[foo, { bar: foo, foo: [foo, { bar: foo }] }, [foo, { bar: foo }]]', array('foo', array('bar' => 'foo', 'foo' => array('foo', array('bar' => 'foo'))), array('foo', array('bar' => 'foo')))),
 
             array('[foo, \'@foo.baz\', { \'%foo%\': \'foo is %foo%\', bar: \'%foo%\' }, true, \'@service_container\']', array('foo', '@foo.baz', array('%foo%' => 'foo is %foo%', 'bar' => '%foo%'), true, '@service_container')),
+
+            array('{ foo: { bar: { 1: 2, baz: 3 } } }', array('foo' => array('bar' => array(1 => 2, 'baz' => 3)))),
         );
     }