diff --git a/.github/CODEOWNERS b/.github/CODEOWNERS
index 415464c40b..0bef18db33 100644
--- a/.github/CODEOWNERS
+++ b/.github/CODEOWNERS
@@ -25,3 +25,5 @@
 /src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/ValidateWorkflowsPass.php @lyrixx
 /src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Compiler/WorkflowGuardListenerPass.php @lyrixx
 /src/Symfony/Component/Workflow/* @lyrixx
+# Yaml
+/src/Symfony/Component/Yaml/* @xabbuh
diff --git a/src/Symfony/Bridge/Twig/Resources/views/Form/bootstrap_4_layout.html.twig b/src/Symfony/Bridge/Twig/Resources/views/Form/bootstrap_4_layout.html.twig
index dc4858e2f3..952ef3aec1 100644
--- a/src/Symfony/Bridge/Twig/Resources/views/Form/bootstrap_4_layout.html.twig
+++ b/src/Symfony/Bridge/Twig/Resources/views/Form/bootstrap_4_layout.html.twig
@@ -189,7 +189,7 @@
         {% elseif type is defined and type == 'file' %}
             {%- set label_attr = label_attr|merge({for: id, class: (label_attr.class|default('') ~ ' custom-file-label')|trim}) -%}
         {%- else -%}
-            {%- set label_attr = label_attr|merge({for: id, class: (label_attr.class|default('') ~ ' form-control-label')|trim}) -%}
+            {%- set label_attr = label_attr|merge({for: id}) -%}
         {%- endif -%}
         {% if required -%}
             {% set label_attr = label_attr|merge({class: (label_attr.class|default('') ~ ' required')|trim}) %}
@@ -284,8 +284,8 @@
     {%- if errors|length > 0 -%}
         <span class="{% if form is not rootform %}invalid-feedback{% else %}alert alert-danger{% endif %} d-block">
             {%- for error in errors -%}
-                <span class="mb-0 d-block">
-                    <span class="initialism form-error-icon badge badge-danger">{{ 'Error'|trans({}, 'validators') }}</span> <span class="form-error-message">{{ error.message }}</span>
+                <span class="d-block">
+                    <span class="form-error-icon badge badge-danger text-uppercase">{{ 'Error'|trans({}, 'validators') }}</span> <span class="form-error-message">{{ error.message }}</span>
                 </span>
             {%- endfor -%}
         </span>
diff --git a/src/Symfony/Bridge/Twig/composer.json b/src/Symfony/Bridge/Twig/composer.json
index 14c80b21a3..839636282c 100644
--- a/src/Symfony/Bridge/Twig/composer.json
+++ b/src/Symfony/Bridge/Twig/composer.json
@@ -23,7 +23,7 @@
         "symfony/asset": "~3.4|~4.0",
         "symfony/dependency-injection": "~3.4|~4.0",
         "symfony/finder": "~3.4|~4.0",
-        "symfony/form": "^4.1",
+        "symfony/form": "^4.1.2",
         "symfony/http-foundation": "~3.4|~4.0",
         "symfony/http-kernel": "~3.4|~4.0",
         "symfony/polyfill-intl-icu": "~1.0",
@@ -41,7 +41,7 @@
         "symfony/workflow": "~3.4|~4.0"
     },
     "conflict": {
-        "symfony/form": "<4.1",
+        "symfony/form": "<4.1.2",
         "symfony/console": "<3.4"
     },
     "suggest": {
diff --git a/src/Symfony/Component/Form/Tests/AbstractBootstrap4HorizontalLayoutTest.php b/src/Symfony/Component/Form/Tests/AbstractBootstrap4HorizontalLayoutTest.php
index 016792e0ed..b78c193c4f 100644
--- a/src/Symfony/Component/Form/Tests/AbstractBootstrap4HorizontalLayoutTest.php
+++ b/src/Symfony/Component/Form/Tests/AbstractBootstrap4HorizontalLayoutTest.php
@@ -33,7 +33,7 @@ abstract class AbstractBootstrap4HorizontalLayoutTest extends AbstractBootstrap4
         ./label[@for="name"]
         [
             ./span[@class="alert alert-danger d-block"]
-                [./span[@class="mb-0 d-block"]
+                [./span[@class="d-block"]
                     [./span[.="[trans]Error[/trans]"]]
                     [./span[.="[trans]Error![/trans]"]]
                 ]
@@ -72,7 +72,7 @@ abstract class AbstractBootstrap4HorizontalLayoutTest extends AbstractBootstrap4
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="col-form-label col-sm-2 form-control-label required"]
+    [@class="col-form-label col-sm-2 required"]
 '
         );
     }
@@ -89,7 +89,7 @@ abstract class AbstractBootstrap4HorizontalLayoutTest extends AbstractBootstrap4
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="my&class col-form-label col-sm-2 form-control-label required"]
+    [@class="my&class col-form-label col-sm-2 required"]
 '
         );
     }
@@ -106,7 +106,7 @@ abstract class AbstractBootstrap4HorizontalLayoutTest extends AbstractBootstrap4
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="my&class col-form-label col-sm-2 form-control-label required"]
+    [@class="my&class col-form-label col-sm-2 required"]
     [.="[trans]Custom label[/trans]"]
 '
         );
@@ -126,7 +126,7 @@ abstract class AbstractBootstrap4HorizontalLayoutTest extends AbstractBootstrap4
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="my&class col-form-label col-sm-2 form-control-label required"]
+    [@class="my&class col-form-label col-sm-2 required"]
     [.="[trans]Custom label[/trans]"]
 '
         );
diff --git a/src/Symfony/Component/Form/Tests/AbstractBootstrap4LayoutTest.php b/src/Symfony/Component/Form/Tests/AbstractBootstrap4LayoutTest.php
index 8cc1df5f52..28b3111c4a 100644
--- a/src/Symfony/Component/Form/Tests/AbstractBootstrap4LayoutTest.php
+++ b/src/Symfony/Component/Form/Tests/AbstractBootstrap4LayoutTest.php
@@ -42,7 +42,7 @@ abstract class AbstractBootstrap4LayoutTest extends AbstractBootstrap3LayoutTest
         ./label[@for="name"]
         [
             ./span[@class="alert alert-danger d-block"]
-                [./span[@class="mb-0 d-block"]
+                [./span[@class="d-block"]
                     [./span[.="[trans]Error[/trans]"]]
                     [./span[.="[trans]Error![/trans]"]]
                 ]
@@ -81,7 +81,7 @@ abstract class AbstractBootstrap4LayoutTest extends AbstractBootstrap3LayoutTest
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="form-control-label required"]
+    [@class="required"]
 '
         );
     }
@@ -98,7 +98,7 @@ abstract class AbstractBootstrap4LayoutTest extends AbstractBootstrap3LayoutTest
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="my&class form-control-label required"]
+    [@class="my&class required"]
 '
         );
     }
@@ -115,7 +115,7 @@ abstract class AbstractBootstrap4LayoutTest extends AbstractBootstrap3LayoutTest
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="my&class form-control-label required"]
+    [@class="my&class required"]
     [.="[trans]Custom label[/trans]"]
 '
         );
@@ -135,7 +135,7 @@ abstract class AbstractBootstrap4LayoutTest extends AbstractBootstrap3LayoutTest
         $this->assertMatchesXpath($html,
 '/label
     [@for="name"]
-    [@class="my&class form-control-label required"]
+    [@class="my&class required"]
     [.="[trans]Custom label[/trans]"]
 '
         );
@@ -189,11 +189,11 @@ abstract class AbstractBootstrap4LayoutTest extends AbstractBootstrap3LayoutTest
 '/span
     [@class="alert alert-danger d-block"]
     [
-        ./span[@class="mb-0 d-block"]
+        ./span[@class="d-block"]
             [./span[.="[trans]Error[/trans]"]]
             [./span[.="[trans]Error 1[/trans]"]]
 
-        /following-sibling::span[@class="mb-0 d-block"]
+        /following-sibling::span[@class="d-block"]
             [./span[.="[trans]Error[/trans]"]]
             [./span[.="[trans]Error 2[/trans]"]]
     ]
diff --git a/src/Symfony/Component/Lock/Store/FlockStore.php b/src/Symfony/Component/Lock/Store/FlockStore.php
index 1ef9ec8472..7578fc5787 100644
--- a/src/Symfony/Component/Lock/Store/FlockStore.php
+++ b/src/Symfony/Component/Lock/Store/FlockStore.php
@@ -81,7 +81,7 @@ class FlockStore implements StoreInterface
         set_error_handler(function ($type, $msg) use (&$error) { $error = $msg; });
         if (!$handle = fopen($fileName, 'r+') ?: fopen($fileName, 'r')) {
             if ($handle = fopen($fileName, 'x')) {
-                chmod($fileName, 0444);
+                chmod($fileName, 0644);
             } elseif (!$handle = fopen($fileName, 'r+') ?: fopen($fileName, 'r')) {
                 usleep(100); // Give some time for chmod() to complete
                 $handle = fopen($fileName, 'r+') ?: fopen($fileName, 'r');