ENGCOM-8038: resolved consistency error for merged indexer xml files #27212

 - Merge Pull Request #27212 from philippsander/magento2:2.4-develop
 - Merged commits:
   1. aef7610
   2. f10c3b3
   3. ef6c7a9
   4. d721107
   5. 963da64

Author: magento-engcom-team

lib/internal/Magento/Framework/Indexer/Test/Unit/_files/invalidIndexerXmlArray.php

@@ -21,6 +21,16 @@
         '<title>Test</title><description>Test</description></indexer></config>',
         ["Element 'indexer': The attribute 'view_id' is required but missing.\nLine: 1\n"],
     ],
+    'indexer_with_wrong_class_name' => [
+        '<?xml version="1.0"?><config><indexer id="somename" view_id="view_01" class="Class+\Name">' .
+        '<title>Test</title><description>Test</description></indexer></config>',
+        [
+            "Element 'indexer', attribute 'class': [facet 'pattern'] The value 'Class+\Name' "
+            . "is not accepted by the pattern '[a-zA-Z|\\\\]+[a-zA-Z0-9\\\\]+'.\nLine: 1\n",
+            "Element 'indexer', attribute 'class': 'Class+\Name' is not a valid value of the atomic type 'classType'."
+            . "\nLine: 1\n"
+        ],
+    ],
     'indexer_duplicate_view_attribute' => [
         '<?xml version="1.0"?><config><indexer id="somename" view_id="view_01" class="Class\Name">' .
         '<title>Test</title><description>Test</description></indexer>' .

lib/internal/Magento/Framework/Indexer/Test/Unit/_files/valid_indexer.xml

@@ -10,7 +10,11 @@
         <title translate="true">Indexer public name</title>
         <description translate="true">Indexer public description</description>
     </indexer>
-    <indexer id="new_indexer_internal_name" view_id="view02" class="Some\Class\Name">
+    <indexer id="second_indexer_internal_name" view_id="view02" class="Some\Class\Name">
+        <title translate="true">Indexer public name</title>
+        <description translate="true">Indexer public description</description>
+    </indexer>
+    <indexer id="third_indexer_internal_name" view_id="view03" class="Some1\Class\Name">
         <title translate="true">Indexer public name</title>
         <description translate="true">Indexer public description</description>
     </indexer>

lib/internal/Magento/Framework/Indexer/etc/indexer_merged.xsd

@@ -57,11 +57,11 @@
     <xs:simpleType name="classType">
         <xs:annotation>
             <xs:documentation>
-                Class name can contain only [a-zA-Z\].
+                Class name can contain only [a-zA-Z|\\]+[a-zA-Z0-9\\]+.
             </xs:documentation>
         </xs:annotation>
         <xs:restriction base="xs:string">
-            <xs:pattern value="[a-zA-Z\\]+" />
+            <xs:pattern value="[a-zA-Z|\\]+[a-zA-Z0-9\\]+"/>
         </xs:restriction>
     </xs:simpleType>