From b7f028fba39026ca92f439c2ba64b0dfa587d429 Mon Sep 17 00:00:00 2001
From: jeremystretch <jstretch@netboxlabs.com>
Date: Wed, 10 May 2023 10:44:01 -0400
Subject: [PATCH] Fixes #12550: Fix rear port selection widget under front port
 creation form

---
 docs/release-notes/version-3.5.md  | 4 ++++
 netbox/dcim/forms/object_create.py | 1 +
 netbox/utilities/forms/mixins.py   | 8 ++++----
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/docs/release-notes/version-3.5.md b/docs/release-notes/version-3.5.md
index b9094a658..36dc97bb9 100644
--- a/docs/release-notes/version-3.5.md
+++ b/docs/release-notes/version-3.5.md
@@ -13,6 +13,10 @@
 * [#12323](https://github.com/netbox-community/netbox/issues/12323) - Add 100GE CXP interface type
 * [#12498](https://github.com/netbox-community/netbox/issues/12498) - Hide map button if `MAPS_URL` is empty
 
+### Bug Fixes
+
+* [#12550](https://github.com/netbox-community/netbox/issues/12550) - Fix rear port selection widget under front port creation form
+
 ---
 
 ## v3.5.1 (2023-05-05)
diff --git a/netbox/dcim/forms/object_create.py b/netbox/dcim/forms/object_create.py
index 236077421..d4c9e6ec3 100644
--- a/netbox/dcim/forms/object_create.py
+++ b/netbox/dcim/forms/object_create.py
@@ -242,6 +242,7 @@ class FrontPortCreateForm(ComponentCreateForm, model_forms.FrontPortForm):
         choices=[],
         label=_('Rear ports'),
         help_text=_('Select one rear port assignment for each front port being created.'),
+        widget=forms.SelectMultiple(attrs={'size': 6})
     )
 
     # Override fieldsets from FrontPortForm to omit rear_port_position
diff --git a/netbox/utilities/forms/mixins.py b/netbox/utilities/forms/mixins.py
index dc9c3eb80..7cdb9731e 100644
--- a/netbox/utilities/forms/mixins.py
+++ b/netbox/utilities/forms/mixins.py
@@ -32,11 +32,11 @@ class BootstrapMixin:
             elif isinstance(field.widget, forms.CheckboxInput):
                 field.widget.attrs['class'] = f'{css} form-check-input'
 
-            elif isinstance(field.widget, forms.SelectMultiple):
-                if 'size' not in field.widget.attrs:
-                    field.widget.attrs['class'] = f'{css} netbox-static-select'
+            elif isinstance(field.widget, forms.SelectMultiple) and 'size' in field.widget.attrs:
+                # Use native Bootstrap class for multi-line <select> widgets
+                field.widget.attrs['class'] = f'{css} form-select form-select-sm'
 
-            elif isinstance(field.widget, forms.Select):
+            elif isinstance(field.widget, (forms.Select, forms.SelectMultiple)):
                 field.widget.attrs['class'] = f'{css} netbox-static-select'
 
             else: