Merge branch '3.4' into 4.0

* 3.4:
  [Translation] Process multiple segments within a single unit.
  Document the container.autowiring.strict_mode option
  fix custom radios/inputs for checkbox/radio type
  Another PR template tweak
  [FrameworkBundle] Add missing XML config for circular_reference_handler. Add tests.
  fix CS
  [PropertyInfo] ReflectionExtractor: give a chance to other extractors if no properties
  Clean calls to http_build_query()
  [WebProfilerBundle] limit ajax request to 100 and remove the last one
  Add support for URL-like DSNs for the PdoSessionHandler
  [HttpFoundation] Fix missing "throw" in JsonResponse
  Improve the documentation of
  Suppress warning from sapi_windows_vt100_support on stream other than STDIO
  removed extra-verbose comments
  Fixes #26136: Avoid emitting warning in hasParameterOption()
  Added a README entry to the PR template
  [HttpFoundation] Add x-zip-compressed to MimeTypeExtensionGuesser.
  [DI] Add null check for removeChild

Author: nicolas-grekas

Resources/views/Form/bootstrap_4_layout.html.twig

@@ -190,7 +190,9 @@
 {% block checkbox_radio_label -%}
     {#- Do not display the label if widget is not defined in order to prevent double label rendering -#}
     {%- if widget is defined -%}
-        {%- if parent_label_class is defined and ('checkbox-custom' in parent_label_class or 'radio-custom' in parent_label_class) -%}
+        {% set is_parent_custom = parent_label_class is defined and ('checkbox-custom' in parent_label_class or 'radio-custom' in parent_label_class) %}
+        {% set is_custom = label_attr.class is defined and ('checkbox-custom' in label_attr.class or 'radio-custom' in label_attr.class) %}
+        {%- if is_parent_custom or is_custom -%}
             {%- set label_attr = label_attr|merge({class: (label_attr.class|default('') ~ ' custom-control-label')|trim}) -%}
         {%- else %}
             {%- set label_attr = label_attr|merge({class: (label_attr.class|default('') ~ ' form-check-label')|trim}) -%}