diff --git a/core/attributedef.class.inc.php b/core/attributedef.class.inc.php
index 823cfa93c..40797d270 100644
--- a/core/attributedef.class.inc.php
+++ b/core/attributedef.class.inc.php
@@ -8599,7 +8599,7 @@ class AttributeBlob extends AttributeDefinition
 	public function RecordAttChange(DBObject $oObject, $original, $value): void
 	{
 		// N°6502 Don't record history if only the download count has changed
-		if ($original->EqualsExceptDownloadsCount($value)) {
+		if ((null !== $original) && (null !== $value) && $original->EqualsExceptDownloadsCount($value)) {
 			return;
 		}
 
diff --git a/sources/Service/Base/ObjectRepository.php b/sources/Service/Base/ObjectRepository.php
index f8ada588a..77eac98e5 100644
--- a/sources/Service/Base/ObjectRepository.php
+++ b/sources/Service/Base/ObjectRepository.php
@@ -38,7 +38,7 @@ class ObjectRepository
 	 *
 	 * @return array|null
 	 */
-	static public function Search(string $sObjectClass, array $aFieldsToLoad, string $sSearch): ?array
+	public static function Search(string $sObjectClass, array $aFieldsToLoad, string $sSearch): ?array
 	{
 		try {
 
@@ -82,7 +82,7 @@ class ObjectRepository
 	 *
 	 * @return array|null
 	 */
-	static public function SearchFromOql(string $sObjectClass, array $aFieldsToLoad, string $sOql, string $sSearch, DBObject $oThisObject = null): ?array
+	public static function SearchFromOql(string $sObjectClass, array $aFieldsToLoad, string $sOql, string $sSearch, DBObject $oThisObject = null): ?array
 	{
 		try {
 
@@ -117,7 +117,7 @@ class ObjectRepository
 	 * @throws \CoreException
 	 * @throws \DictExceptionMissingString
 	 */
-	static private function DBSetToObjectArray(iDBObjectSetIterator $oDbObjectSet, string $sObjectClass, array $aFieldsToLoad): array
+	private static function DBSetToObjectArray(iDBObjectSetIterator $oDbObjectSet, string $sObjectClass, array $aFieldsToLoad): array
 	{
 		// Retrieve friendly name complementary specification
 		$aComplementAttributeSpec = MetaModel::GetNameSpec($sObjectClass, FriendlyNameType::COMPLEMENTARY);
@@ -158,7 +158,7 @@ class ObjectRepository
 	 *
 	 * @return mixed
 	 */
-	static public function GetDefaultFieldsToLoad(array $aComplementAttributeSpec, string $sObjectImageAttCode)
+	public static function GetDefaultFieldsToLoad(array $aComplementAttributeSpec, string $sObjectImageAttCode)
 	{
 		// Friendly name complementary fields
 		$aFieldsToLoad = $aComplementAttributeSpec[1];
@@ -185,7 +185,7 @@ class ObjectRepository
 	 *
 	 * @return array
 	 */
-	static public function ComputeOthersData(DBObject $oDbObject, string $sClass, array $aData, array $aComplementAttributeSpec, string $sObjectImageAttCode): array
+	public static function ComputeOthersData(DBObject $oDbObject, string $sClass, array $aData, array $aComplementAttributeSpec, string $sObjectImageAttCode): array
 	{
 		try {
 
@@ -196,6 +196,7 @@ class ObjectRepository
 			$aData['obsolescence_flag'] = $oDbObject->IsObsolete();
 
 			// Additional fields
+			$sFriendlynameForHtml = utils::EscapeHtml($aData['friendlyname']);
 			if (count($aComplementAttributeSpec[1]) > 0) {
 				$aData['has_additional_field'] = true;
 				$aArguments = [];
@@ -203,9 +204,10 @@ class ObjectRepository
 					$aArguments[] = $oDbObject->Get($sAdditionalField);
 				}
 				$aData['additional_field'] = vsprintf($aComplementAttributeSpec[0], $aArguments);
-				$aData['full_description'] = "{$aData['friendlyname']}<br><i><small>{$aData['additional_field']}</small></i>";
+				$sAdditionalFieldForHtml = utils::EscapeHtml($aData['additional_field']);
+				$aData['full_description'] = "{$sFriendlynameForHtml}<br><i><small>{$sAdditionalFieldForHtml}</small></i>";
 			} else {
-				$aData['full_description'] = $aData['friendlyname'];
+				$aData['full_description'] = $sFriendlynameForHtml;
 			}
 
 			// Image
@@ -308,7 +310,7 @@ class ObjectRepository
 	 *
 	 * @return bool
 	 */
-	static public function DeleteFromOql(string $sOql): bool
+	public static function DeleteFromOql(string $sOql): bool
 	{
 		try {
 
diff --git a/tests/php-unit-tests/unitary-tests/core/ormDocumentTest.php b/tests/php-unit-tests/unitary-tests/core/ormDocumentTest.php
new file mode 100644
index 000000000..e9d33871c
--- /dev/null
+++ b/tests/php-unit-tests/unitary-tests/core/ormDocumentTest.php
@@ -0,0 +1,142 @@
+<?php
+/*!
+ * @copyright   Copyright (C) 2010-2023 Combodo SARL
+ * @license     http://opensource.org/licenses/AGPL-3.0
+ */
+
+namespace Combodo\iTop\Test\UnitTest\Core;
+
+use Combodo\iTop\Test\UnitTest\ItopDataTestCase;
+use ormDocument;
+
+/**
+ * Tests of the ormDocument class
+ */
+class ormDocumentTest extends ItopDataTestCase
+{
+	/**
+	 * @inheritDoc
+	 */
+	protected function LoadRequiredItopFiles(): void
+	{
+		parent::LoadRequiredItopFiles();
+
+		$this->RequireOnceItopFile('core/ormdocument.class.inc.php');
+	}
+
+
+	/**
+	 * @param array $aDocAData
+	 * @param array $aDocBData
+	 * @param bool $bExpectedResult
+	 *
+	 * @dataProvider EqualsExceptDownloadsCountProvider
+	 */
+	public function testEqualsExceptDownloadsCount(array $aDocAData, array $aDocBData, bool $bExpectedResult)
+	{
+		$oDocA = new ormDocument(base64_decode($aDocAData[0]), $aDocAData[1], $aDocAData[2], $aDocAData[3]);
+		$oDocB = new ormDocument(base64_decode($aDocBData[0]), $aDocBData[1], $aDocBData[2], $aDocBData[3]);
+
+		$bTestedResult = $oDocA->EqualsExceptDownloadsCount($oDocB);
+		$this->assertSame($bExpectedResult, $bTestedResult);
+	}
+
+	public function EqualsExceptDownloadsCountProvider(): array
+	{
+		$sFirstDummyTextFileContentBase64 = "Rmlyc3Q=";
+		$sSecondDummyTextFileContentBase64 = "U2Vjb25k";
+
+		return [
+			'Total different files' => [
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				[
+					$sSecondDummyTextFileContentBase64,
+					"image/png",
+					"b.png",
+					1
+				],
+				false,
+			],
+			'Different data only' => [
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				[
+					$sSecondDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				false,
+			],
+			'Different mime types only' => [
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				[
+					$sFirstDummyTextFileContentBase64,
+					"image/png",
+					"a.txt",
+					0
+				],
+				false,
+			],
+			'Different file names only' => [
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"b.txt",
+					0
+				],
+				false,
+			],
+			'Different download counts only' => [
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					1
+				],
+				true,
+			],
+			'Identical files, different object instances' => [
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				[
+					$sFirstDummyTextFileContentBase64,
+					"text/plain",
+					"a.txt",
+					0
+				],
+				false,
+			],
+		];
+	}
+}