Fixed #2498

CHANGELOG.md

@@ -5,6 +5,9 @@
 ### Changed
 - Craft now throws an exception if it detects that a `max_input_vars` error occurred. ([#876](https://github.com/craftcms/cms/issues/876))
 
+### Fixed
+- Fixed a bug where entry version data was not including newly-created Matrix block IDs, so they would be re-created from scratch when loading the version. ([#2498](https://github.com/craftcms/cms/issues/2498))
+
 ## 2.6.3010 - 2018-02-21
 
 ### Changed

src/fieldtypes/MatrixFieldType.php

@@ -394,6 +394,7 @@ public function prepValueFromPost($data)
 			if (strncmp($blockId, 'new', 3) === 0 || !isset($oldBlocksById[$blockId]))
 			{
 				$block = new MatrixBlockModel();
+				$block->postId  = $blockId;
 				$block->fieldId = $this->model->id;
 				$block->typeId  = $blockType->id;
 				$block->ownerId = $ownerId;

src/models/MatrixBlockModel.php

@@ -259,6 +259,7 @@ protected function defineAttributes()
 			'typeId'      => AttributeType::Number,
 			'sortOrder'   => AttributeType::Number,
 
+			'postId'      => AttributeType::String,
 			'collapsed'   => AttributeType::Bool,
 		));
 	}

src/services/MatrixService.php

@@ -864,6 +864,10 @@ public function saveField(MatrixFieldType $fieldType)
 			$blocks = array();
 		}
 
+		$allPostContent = $owner->getContentFromPost();
+		$postContent = isset($allPostContent[$field->handle]) ? $allPostContent[$field->handle] : null;
+		$newPostContent = array();
+
 		$transaction = craft()->db->getCurrentTransaction() === null ? craft()->db->beginTransaction() : null;
 		try
 		{
@@ -888,6 +892,13 @@ public function saveField(MatrixFieldType $fieldType)
 				{
 					$collapsedBlockIds[] = $block->id;
 				}
+
+				// Update the post content
+				$postId = $block->postId ?: $block->id;
+				if (isset($postContent[$postId]))
+				{
+					$newPostContent[$block->id] = $postContent[$postId];
+				}
 			}
 
 			// Get the IDs of blocks that are row deleted
@@ -931,6 +942,12 @@ public function saveField(MatrixFieldType $fieldType)
 			throw $e;
 		}
 
+		// Update the post content on the owner element
+		if ($postContent !== null)
+		{
+			$owner->setRawPostContent($field->handle, $newPostContent);
+		}
+
 		// Tell the browser to collapse any new block IDs
 		if (!craft()->isConsole() && $collapsedBlockIds)
 		{