[6.x] Fix blueprint fields being rebuilt for every entry

src/Fields/Blueprint.php

@@ -334,7 +334,15 @@ public function setParent($parent)
     {
         $this->parent = $parent;
 
-        $this->resetBlueprintCache()->resetFieldsCache();
+        $this->resetFieldsCache();
+
+        // The cache survives when the new parent uses the same blueprint. Give the new
+        // parent copies of the fields, so fields handed out earlier keep their parent.
+        if ($this->fieldsCache) {
+            $this->fieldsCache = $this->fieldsCache->newInstance()
+                ->setFields($this->fieldsCache->all()->map(fn ($field) => clone $field))
+                ->setParent($parent);
+        }
 
         return $this;
     }

tests/Data/Entries/EntryTest.php

@@ -4,6 +4,7 @@
 
 use BadMethodCallException;
 use Facades\Statamic\Fields\BlueprintRepository;
+use Facades\Statamic\Fields\FieldRepository;
 use Facades\Statamic\Stache\Repositories\CollectionTreeRepository;
 use Facades\Tests\Factories\EntryFactory;
 use Illuminate\Contracts\Support\Arrayable;
@@ -32,6 +33,7 @@
 use Statamic\Facades;
 use Statamic\Facades\Blink;
 use Statamic\Fields\Blueprint;
+use Statamic\Fields\Field;
 use Statamic\Fields\Fieldtype;
 use Statamic\Fields\Value;
 use Statamic\Sites\Site;
@@ -1273,6 +1275,38 @@ public function it_gets_and_sets_the_published_state()
         $this->assertFalse($entry->published());
     }
 
+    #[Test]
+    public function entries_with_the_same_blueprint_resolve_its_fields_once()
+    {
+        $finds = 0;
+        FieldRepository::shouldReceive('find')
+            ->with('fieldset_one.field_one')
+            ->andReturnUsing(function () use (&$finds) {
+                $finds++;
+
+                return new Field('field_one', ['type' => 'text']);
+            });
+
+        BlueprintRepository::shouldReceive('in')->with('collections/blog')->andReturn(collect([
+            'article' => (new Blueprint)->setHandle('article')->setContents([
+                'fields' => [['handle' => 'one', 'field' => 'fieldset_one.field_one']],
+            ]),
+        ]));
+        Collection::make('blog')->dated(true)->save();
+
+        // Setting the date reads the blueprint's date field, as it happens for every entry loaded from storage.
+        $makeEntry = fn ($i) => (new Entry)->id("entry-{$i}")->collection('blog')->blueprint('article')->date("2024-01-0{$i}");
+
+        $this->assertSame($entry = $makeEntry(1), $entry->blueprint()->field('one')->parent());
+        $findsForOneBuild = $finds;
+
+        foreach (range(2, 5) as $i) {
+            $this->assertSame($entry = $makeEntry($i), $entry->blueprint()->field('one')->parent());
+        }
+
+        $this->assertSame($findsForOneBuild, $finds);
+    }
+
     #[Test]
     public function it_gets_the_blueprint_when_defined_on_itself()
     {

tests/Feature/Entries/EntryRevisionsTest.php

@@ -7,6 +7,7 @@
 use Illuminate\Support\Carbon;
 use Illuminate\Support\Facades\Event;
 use Illuminate\Support\Facades\Queue;
+use PHPUnit\Framework\Attributes\DataProvider;
 use PHPUnit\Framework\Attributes\Test;
 use Statamic\Events\EntryDeleted;
 use Statamic\Events\EntryDeleting;
@@ -326,6 +327,39 @@ public function it_unpublishes_an_entry()
         $this->assertEquals('unpublish', $revision->action());
     }
 
+    #[Test]
+    #[DataProvider('workingCopyActionsProvider')]
+    public function blueprint_fields_point_to_the_new_entry_after_publishing_or_unpublishing_a_working_copy($method)
+    {
+        $this->setTestBlueprint('test', ['foo' => ['type' => 'text']]);
+
+        $entry = EntryFactory::id('1')
+            ->slug('test')
+            ->collection('blog')
+            ->published($method === 'unpublishWorkingCopy')
+            ->date('2010-12-25')
+            ->data(['blueprint' => 'test', 'title' => 'Title', 'foo' => 'bar'])
+            ->create();
+
+        $entry->makeWorkingCopy()->save();
+
+        $this->assertSame($entry, $entry->blueprint()->setParent($entry)->field('foo')->parent());
+
+        $published = $entry->{$method}();
+
+        $this->assertNotSame($entry, $published);
+        $this->assertSame($published, $published->blueprint()->field('foo')->parent());
+        $this->assertSame($published, $published->blueprint()->parent());
+    }
+
+    public static function workingCopyActionsProvider()
+    {
+        return [
+            'publish' => ['publishWorkingCopy'],
+            'unpublish' => ['unpublishWorkingCopy'],
+        ];
+    }
+
     #[Test]
     public function it_denies_creating_a_revision_without_permission_to_edit_entry()
     {

tests/Fields/BlueprintTest.php

@@ -868,6 +868,56 @@ public function it_can_add_fields_multiple_times()
 
     }
 
+    #[Test]
+    public function it_keeps_the_fields_when_the_parent_changes_to_one_with_the_same_blueprint()
+    {
+        $finds = 0;
+        FieldRepository::shouldReceive('find')
+            ->with('fieldset_one.field_one')
+            ->andReturnUsing(function () use (&$finds) {
+                $finds++;
+
+                return new Field('field_one', ['type' => 'text']);
+            });
+
+        $blueprint = (new Blueprint)
+            ->setNamespace('collections/collection_one')
+            ->setHandle('blueprint_one')
+            ->setContents(['fields' => [['handle' => 'one', 'field' => 'fieldset_one.field_one']]]);
+
+        $collection = tap(StatamicCollection::make('collection_one'))->save();
+        $entryA = (new Entry)->collection($collection)->blueprint('blueprint_one');
+        $entryB = (new Entry)->collection($collection)->blueprint('blueprint_one');
+
+        $this->assertSame($entryA, $blueprint->setParent($entryA)->field('one')->parent());
+        $findsForOneBuild = $finds;
+
+        foreach ([$entryB, $entryA, $entryB] as $entry) {
+            $this->assertSame($entry, $blueprint->setParent($entry)->field('one')->parent());
+        }
+
+        $this->assertSame($findsForOneBuild, $finds);
+    }
+
+    #[Test]
+    public function fields_keep_their_parent_when_the_blueprint_moves_to_another_parent()
+    {
+        $blueprint = (new Blueprint)
+            ->setNamespace('collections/collection_one')
+            ->setHandle('blueprint_one')
+            ->setContents(['fields' => [['handle' => 'one', 'field' => ['type' => 'text']]]]);
+
+        $collection = tap(StatamicCollection::make('collection_one'))->save();
+        $entryA = (new Entry)->collection($collection)->blueprint('blueprint_one');
+        $entryB = (new Entry)->collection($collection)->blueprint('blueprint_one');
+
+        $fieldA = $blueprint->setParent($entryA)->field('one');
+        $fieldB = $blueprint->setParent($entryB)->field('one');
+
+        $this->assertSame($entryA, $fieldA->parent());
+        $this->assertSame($entryB, $fieldB->parent());
+    }
+
     #[Test]
     public function it_ensures_a_field_has_config()
     {