Enable Model lazy updating based on only the changed data

- Simplify update decision in Database

src/BaseModel.php

@@ -28,6 +28,13 @@ abstract class BaseModel
 	 */
 	private $data = [];
 
+	/**
+	 * Used to limit/avoid updates if no data was changed.
+	 *
+	 * @var array
+	 */
+    private $originalData = [];
+
 	/**
 	 * @param Database        $dba
 	 * @param LoggerInterface $logger
@@ -38,6 +45,12 @@ abstract class BaseModel
 		$this->dba = $dba;
 		$this->logger = $logger;
 		$this->data = $data;
+		$this->originalData = $data;
+	}
+
+	public function getOriginalData()
+	{
+		return $this->originalData;
 	}
 
 	/**
@@ -51,6 +64,7 @@ abstract class BaseModel
 	{
 		$model = clone $prototype;
 		$model->data = $data;
+		$model->originalData = $data;
 
 		return $model;
 	}

src/BaseRepository.php

@@ -122,7 +122,7 @@ abstract class BaseRepository extends BaseFactory
 	 */
 	public function update(BaseModel $model)
 	{
-		return $this->dba->update(static::$table_name, $model->toArray(), ['id' => $model->id], true);
+		return $this->dba->update(static::$table_name, $model->toArray(), ['id' => $model->id], $model->getOriginalData());
 	}
 
 	/**
@@ -136,10 +136,12 @@ abstract class BaseRepository extends BaseFactory
 	{
 		$return = $this->dba->insert(static::$table_name, $fields);
 
-		if ($return) {
+		if (!$return) {
+			throw new HTTPException\InternalServerErrorException('Unable to insert new row in table "' . static::$table_name . '"');
+		}
+
 		$fields['id'] = $this->dba->lastInsertId();
 		$return = $this->create($fields);
-		}
 
 		return $return;
 	}

src/Database/Database.php

@@ -1342,19 +1342,13 @@ class Database
 			}
 		}
 
-		$do_update = (count($old_fields) == 0);
-
 		foreach ($old_fields AS $fieldname => $content) {
-			if (isset($fields[$fieldname])) {
-				if (($fields[$fieldname] == $content) && !is_null($content)) {
+			if (isset($fields[$fieldname]) && !is_null($content) && ($fields[$fieldname] == $content)) {
 				unset($fields[$fieldname]);
-				} else {
-					$do_update = true;
-				}
 			}
 		}
 
-		if (!$do_update || (count($fields) == 0)) {
+		if (count($fields) == 0) {
 			return true;
 		}