From e42ee936dd3e800cbfd4d2bbfff78bd9709649a9 Mon Sep 17 00:00:00 2001
From: MyuTsu <gaetan.langlois31@gmail.com>
Date: Thu, 5 Feb 2026 14:00:53 +0100
Subject: [PATCH 1/3] fix(dropdown): handle empty default value to prevent
 error

---
 CHANGELOG.md            | 3 +++
 inc/container.class.php | 6 +++++-
 inc/field.class.php     | 2 ++
 3 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index ee6bf7bd..adf4880d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -11,6 +11,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 - Add compatibility with GLPI `CustomAsset`
 
+### Fixed
+
+- Fix empty default value in multiple dropdown fields
 
 ## [1.23.2] - 2025-12-22
 
diff --git a/inc/container.class.php b/inc/container.class.php
index f31e4241..62070144 100644
--- a/inc/container.class.php
+++ b/inc/container.class.php
@@ -1354,7 +1354,11 @@ public function updateFieldsValues($data, $itemtype, $massiveaction = false)
                     $data[$field_name] = json_encode(array_values(array_unique(array_merge($existing_values, $new_values))));
 
                 } else {
-                    $data[$field_name] = json_encode($data[$field_name]);
+                    $value = $data[$field_name];
+                    if (!is_array($value)) {
+                        $value = ($value === '' || $value === null) ? [] : [$value];
+                    }
+                    $data[$field_name] = json_encode($value);
                 }
             } elseif (array_key_exists('_' . $field_name . '_defined', $data)) {
                 $data[$field_name] = json_encode([]);
diff --git a/inc/field.class.php b/inc/field.class.php
index 0939fe9b..adf19da8 100644
--- a/inc/field.class.php
+++ b/inc/field.class.php
@@ -1279,6 +1279,8 @@ public static function prepareHtmlFields(
                 //
                 // -> Decode it only if it is not already an array.
                 $value = json_decode((string) $value);
+                $decoded = json_decode((string) $value, true);
+                $value = is_array($decoded) ? $decoded : [];
             }
 
             $field['value'] = $value;

From 8efab96115297c873197422ab7d5aef0ac0d24ac Mon Sep 17 00:00:00 2001
From: MyuTsu <gaetan.langlois31@gmail.com>
Date: Thu, 5 Feb 2026 14:16:35 +0100
Subject: [PATCH 2/3] fix

---
 inc/field.class.php | 1 -
 1 file changed, 1 deletion(-)

diff --git a/inc/field.class.php b/inc/field.class.php
index adf19da8..f07d7f79 100644
--- a/inc/field.class.php
+++ b/inc/field.class.php
@@ -1278,7 +1278,6 @@ public static function prepareHtmlFields(
                 // - either from a previous input (it will be an array).
                 //
                 // -> Decode it only if it is not already an array.
-                $value = json_decode((string) $value);
                 $decoded = json_decode((string) $value, true);
                 $value = is_array($decoded) ? $decoded : [];
             }

From 5117dfd0dc307418e4dba8a79fc382366103866a Mon Sep 17 00:00:00 2001
From: MyuTsu <gaetan.langlois31@gmail.com>
Date: Thu, 5 Feb 2026 14:19:45 +0100
Subject: [PATCH 3/3] fix

---
 inc/container.class.php | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/inc/container.class.php b/inc/container.class.php
index 62070144..9c1230d8 100644
--- a/inc/container.class.php
+++ b/inc/container.class.php
@@ -1355,9 +1355,7 @@ public function updateFieldsValues($data, $itemtype, $massiveaction = false)
 
                 } else {
                     $value = $data[$field_name];
-                    if (!is_array($value)) {
-                        $value = ($value === '' || $value === null) ? [] : [$value];
-                    }
+                    $value = is_array($value) ? $value : [];
                     $data[$field_name] = json_encode($value);
                 }
             } elseif (array_key_exists('_' . $field_name . '_defined', $data)) {