Updated the patch changes for 2.0.x branch

config/schema/inline_entity_form.schema.yml

@@ -69,6 +69,9 @@ field.widget.settings.inline_entity_form_complex:
     allow_existing:
       type: boolean
       label: "Allow existing"
+    allow_edit:
+      type: boolean
+      label: "Allow edit"
     match_operator:
       type: string
       label: "Match operator"

src/Plugin/Field/FieldWidget/InlineEntityFormComplex.php

@@ -119,6 +119,7 @@ class InlineEntityFormComplex extends InlineEntityFormBase implements ContainerF
     $defaults += [
       'allow_new' => TRUE,
       'allow_existing' => FALSE,
+      'allow_edit' => TRUE,
       'removed_reference' => self::REMOVED_OPTIONAL,
       'match_operator' => 'CONTAINS',
       'allow_duplicate' => FALSE,
@@ -153,6 +154,11 @@ class InlineEntityFormComplex extends InlineEntityFormBase implements ContainerF
       '#title' => $this->t('Allow users to add existing @label.', ['@label' => $labels['plural']]),
       '#default_value' => $this->getSetting('allow_existing'),
     ];
+    $element['allow_edit'] = [
+      '#type' => 'checkbox',
+      '#title' => $this->t('Allow users to edit existing @label.', ['@label' => $labels['plural']]),
+      '#default_value' => $this->getSetting('allow_edit'),
+    ];
     $element['match_operator'] = [
       '#type' => 'select',
       '#title' => $this->t('Autocomplete matching'),
@@ -465,7 +471,7 @@ class InlineEntityFormComplex extends InlineEntityFormBase implements ContainerF
 
         // Make sure entity_access is not checked for unsaved entities.
         $entity_id = $entity->id();
-        if (empty($entity_id) || $entity->access('update')) {
+        if (empty($entity_id) || ($settings['allow_edit'] && $entity->access('update'))) {
           $row['actions']['ief_entity_edit'] = [
             '#type' => 'submit',
             '#value' => $this->t('Edit'),

tests/src/FunctionalJavascript/ComplexWidgetTest.php

@@ -105,8 +105,9 @@ class ComplexWidgetTest extends InlineEntityFormTestBase {
     $assert_session->elementExists('xpath', $last_name_field_xpath);
     $assert_session->buttonExists('Create node');
 
-    // Allow addition of existing nodes.
+    // Allow addition of existing nodes and disable edition.
     $this->updateSetting('allow_existing', TRUE);
+    $this->updateSetting('allow_edit', FALSE);
 
     // Asserts 'Add new node' form elements.
     $this->drupalGet($this->formContentAddUrl);
@@ -355,7 +356,12 @@ class ComplexWidgetTest extends InlineEntityFormTestBase {
 
     $parent_node = $this->drupalGetNodeByTitle('Some title');
 
-    // Edit the second entity.
+    // Unable to edit second entity, feature disabled.
+    $this->drupalGet('node/' . $parent_node->id() . '/edit');
+    $assert_session->elementNotExists('xpath', '(//input[@value="Edit"])[2]');
+
+    // Edit the second entity once edit is enabled.
+    $this->updateSetting('allow_edit', TRUE);
     $this->drupalGet('node/' . $parent_node->id() . '/edit');
     $assert_session->elementExists('xpath', '(//input[@value="Edit"])[2]')->press();
     $this->assertNotEmpty($assert_session->waitForElement('xpath', $inner_title_field_xpath));