[6.x] Don't reset revisions when saving a collection with the field hidden

src/Http/Controllers/CP/Collections/CollectionsController.php

@@ -332,7 +332,6 @@ public function update(Request $request, $collection)
             ->defaultPublishState($values['default_publish_state'])
             ->sortDirection($values['sort_direction'])
             ->mount($values['mount'] ?? null)
-            ->revisionsEnabled($values['revisions'] ?? false)
             ->taxonomies($values['taxonomies'] ?? [])
             ->futureDateBehavior(Arr::get($values, 'future_date_behavior'))
             ->pastDateBehavior(Arr::get($values, 'past_date_behavior'))
@@ -342,6 +341,10 @@ public function update(Request $request, $collection)
             ->requiresSlugs($values['require_slugs'])
             ->previewTargets($values['preview_targets']);
 
+        if (array_key_exists('revisions', $values)) {
+            $collection->revisionsEnabled($values['revisions']);
+        }
+
         if ($sites = Arr::get($values, 'sites')) {
             $collection
                 ->sites($sites)

tests/Feature/Collections/UpdateCollectionTest.php

@@ -153,6 +153,40 @@ public function settings_links_to_true_will_also_create_the_default_blueprint_if
         $this->assertEquals(['test', 'link'], $blueprints->map->handle()->values()->all());
     }
 
+    #[Test]
+    public function it_updates_revisions()
+    {
+        config(['statamic.revisions.enabled' => true]);
+
+        $collection = tap(Collection::make('test')->revisionsEnabled(false))->save();
+
+        $this
+            ->actingAs($this->userWithPermission())
+            ->update($collection, ['revisions' => true])
+            ->assertOk();
+
+        $this->assertTrue(Collection::findByHandle('test')->revisionsEnabled());
+    }
+
+    #[Test]
+    public function it_doesnt_update_revisions_when_the_field_is_hidden()
+    {
+        config(['statamic.revisions.enabled' => true]);
+
+        $collection = tap(Collection::make('test')->revisionsEnabled(true))->save();
+
+        config(['statamic.revisions.enabled' => false]);
+
+        $this
+            ->actingAs($this->userWithPermission())
+            ->update($collection)
+            ->assertOk();
+
+        config(['statamic.revisions.enabled' => true]);
+
+        $this->assertTrue(Collection::findByHandle('test')->revisionsEnabled());
+    }
+
     private function userWithoutPermission()
     {
         $this->setTestRoles(['test' => ['access cp']]);