From dd44a9efcc65441abeb62b526e099416d02bfad0 Mon Sep 17 00:00:00 2001
From: tremo <tarekrummo64@gmail.com>
Date: Fri, 15 May 2026 15:14:51 +0200
Subject: [PATCH 1/4] fix: nested array stored in DB for readonly dropdown

---
 inc/container.class.php | 26 +++++++++++++++++++++++++-
 1 file changed, 25 insertions(+), 1 deletion(-)

diff --git a/inc/container.class.php b/inc/container.class.php
index bd663d6f..3c109cf6 100644
--- a/inc/container.class.php
+++ b/inc/container.class.php
@@ -1413,11 +1413,12 @@ public function updateFieldsValues($data, $itemtype, $massiveaction = false)
                     // Add new values to existing ones
                     $existing_values = json_decode($obj->fields[$field_name] ?? '[]', true);
                     $new_values      = is_array($data[$field_name]) ? $data[$field_name] : [$data[$field_name]];
+                    $new_values      = $this->flattenScalars($new_values);
                     $data[$field_name] = json_encode(array_values(array_unique(array_merge($existing_values, $new_values))));
 
                 } else {
                     $value = $data[$field_name];
-                    $value = is_array($value) ? $value : [];
+                    $value = is_array($value) ? $this->flattenScalars($value) : [];
                     $data[$field_name] = json_encode($value);
                 }
             } elseif (array_key_exists('_' . $field_name . '_defined', $data)) {
@@ -1966,6 +1967,29 @@ public static function preItem(CommonDBTM $item)
         return false;
     }
 
+    /**
+     * Flatten a one-level-deep array of mixed scalars/arrays into a flat array of scalars.
+     * Guards against nested arrays produced when a readonly multiple-dropdown field submits
+     * with a doubly-bracketed name (e.g. foo[][][]).
+     */
+    private function flattenScalars(array $values): array
+    {
+        $flat = [];
+        foreach ($values as $v) {
+            if (is_array($v)) {
+                foreach ($v as $inner) {
+                    if (is_scalar($inner)) {
+                        $flat[] = $inner;
+                    }
+                }
+            } elseif (is_scalar($v)) {
+                $flat[] = $v;
+            }
+        }
+
+        return $flat;
+    }
+
     /**
      * Populates fields data from item
      *

From 300525e085e628e0add1662b2d8b404f932de913 Mon Sep 17 00:00:00 2001
From: tremo <tarekrummo64@gmail.com>
Date: Fri, 15 May 2026 15:31:29 +0200
Subject: [PATCH 2/4] CHANGELOG

---
 CHANGELOG.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d00feb06..997e5a1c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ### Fixed
 
+- Fix nested array stored in DB for readonly dropdown
 - Fix migration abort when a GenericObject container name produces a table name exceeding MySQL's 64-character limit after conversion to GlpiCustomAsset.
 - Fix empty dropdown value (-1) on form submission
 - Fix text area fields size and alignment

From 60683440adec793e6360f459c073f4da272c8cb2 Mon Sep 17 00:00:00 2001
From: tremo <tarekrummo64@gmail.com>
Date: Fri, 15 May 2026 15:38:45 +0200
Subject: [PATCH 3/4] flatten values already corrupted in db at display time

---
 inc/field.class.php | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/inc/field.class.php b/inc/field.class.php
index 039e812f..44bf2cd8 100644
--- a/inc/field.class.php
+++ b/inc/field.class.php
@@ -1283,6 +1283,18 @@ public static function prepareHtmlFields(
                 $value = is_array($decoded) ? $decoded : [];
             }
 
+            if ($field['multiple'] && is_array($value)) {
+                // Flatten any nested arrays caused by corrupted DB data (double-encoded values)
+                // so that Dropdown::show() always receives a flat list of scalars.
+                $value = array_values(array_filter(
+                    array_merge(...array_map(
+                        static fn($v) => is_array($v) ? array_values($v) : [$v],
+                        $value,
+                    )),
+                    is_scalar(...),
+                ));
+            }
+
             $field['value'] = $value;
         }
 

From e2ade040a6832c1a16cdc6596fc49087a53f0513 Mon Sep 17 00:00:00 2001
From: tremo <tarekrummo64@gmail.com>
Date: Mon, 18 May 2026 10:18:06 +0200
Subject: [PATCH 4/4] refactor function

---
 inc/container.class.php | 17 +++++------------
 1 file changed, 5 insertions(+), 12 deletions(-)

diff --git a/inc/container.class.php b/inc/container.class.php
index 3c109cf6..c3956d33 100644
--- a/inc/container.class.php
+++ b/inc/container.class.php
@@ -1969,25 +1969,18 @@ public static function preItem(CommonDBTM $item)
 
     /**
      * Flatten a one-level-deep array of mixed scalars/arrays into a flat array of scalars.
-     * Guards against nested arrays produced when a readonly multiple-dropdown field submits
-     * with a doubly-bracketed name (e.g. foo[][][]).
+     *
+     * @param array<mixed, mixed> $values
+     * @return array<mixed, mixed> $values the flattened array with only scalar values
      */
     private function flattenScalars(array $values): array
     {
         $flat = [];
         foreach ($values as $v) {
-            if (is_array($v)) {
-                foreach ($v as $inner) {
-                    if (is_scalar($inner)) {
-                        $flat[] = $inner;
-                    }
-                }
-            } elseif (is_scalar($v)) {
-                $flat[] = $v;
-            }
+            array_push($flat, ...(is_array($v) ? $v : [$v]));
         }
 
-        return $flat;
+        return array_values(array_filter($flat, is_scalar(...)));
     }
 
     /**