bug #6002 Fix incorrect '' test in form theme causing regression (wiz…

…hippo)

This PR was merged into the 4.x branch.

Discussion
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Fix incorrect '' test in form theme causing regression

Fix regression introduced by 7fdd14d

See #6001

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Commits
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220708f Fix regression issue 6001

src/Resources/views/crud/form_theme.html.twig

@@ -257,7 +257,7 @@
         {% if required -%}
             {% set label_attr = label_attr|merge({class: (label_attr.class|default('') ~ ' required')|trim}) %}
         {%- endif -%}
-        {% if label == '' -%}
+        {% if label is same as('') -%}
             {# don't process the label; this is used to not display any label content
                but render an empty <label> element keep the form layout #}
         {%- elseif label is null -%}