Issue #3000552 by Renrhaf, vishalkhode, yrocq, umirtma, Krzysztof Domański,...

Issue #3000552 by Renrhaf, vishalkhode, yrocq, umirtma, Krzysztof Domański, cgomezg: Entity browser fields giving error when clicked on add new or add existing button

src/Plugin/Validation/Constraint/NodeTitleConstraintValidator.php

@@ -171,24 +171,19 @@ class NodeTitleConstraintValidator extends ConstraintValidator implements Contai
       }
       if ($config_key == 'unique-' . $node_type || $config_key == 'unique') {
         if ($config_value == 1) {
-          $titleExists = FALSE;
-
-          // Get existing nodes with same title and type.
-          $nodes = $nodeStorage->loadByProperties([
-            'title' => $value_title,
-            'type' => $node_type,
-          ]);
-
-          if (!empty($nodes)) {
-            $titleExists = TRUE;
-            if (!$node->isNew() && $node->getTitle() === $value_title) {
-              // If title is the current node one, do not display error.
-              $titleExists = FALSE;
-            }
+          // Unique node title for all content types('unique')
+          $properties = ['title' => $value_title];
+          if ($config_key == 'unique-' . $node_type) {
+            // Unique node title for one content type('unique-')
+            $properties['type'] = $node_type;
+          }
+          $nodes = $nodeStorage->loadByProperties($properties);
+          // Remove current node form list
+          if (isset($nodes[$node->id()])) {
+            unset($nodes[$node->id()]);
           }
-
           // Show error.
-          if ($titleExists) {
+          if (!empty($nodes)) {
             $message = $this->t("The title must be unique. Other content is already using this title: @title", ['@title' => $value_title]);
             $this->context->addViolation($message);
           }