[PATCH manager] fix #8046: ui: ceph: fix muting a health check with no expiry

[Kefu Chai <k.chai@proxmox.com>]

Ext.form.field.ComboBox cannot round-trip an empty string as a store
record's key. Selecting the 'No expiry' item, keyed '', submitted the
record's internal id (e.g. 'KeyValue-1') instead, and the API rejected
that as an invalid ttl.

The cause is in Proxmox.form.KVComboBox's backing model: it uses the
same field, 'key', for both idProperty and valueField. Ext.data.Model
replaces a falsy id with an autogenerated one on that field, so a
record keyed '' gets its key overwritten. Use the toolkit's
'__default__' sentinel instead; Proxmox.form.KVComboBox already drops
that value on submit, so choosing no expiry now sends no ttl at all.
Most other proxmoxKVComboBox fields in this tree already key their
'unset' item as '__default__' (AuthEditLDAP.js, MachineEdit.js,
SystemEdit.js, and roughly two dozen more); HealthMute.js was the one
place still using ''.

Signed-off-by: Kefu Chai <k.chai@proxmox.com>
---
 www/manager6/ceph/HealthMute.js | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/www/manager6/ceph/HealthMute.js b/www/manager6/ceph/HealthMute.js
index 8ea73635..5d356686 100644
--- a/www/manager6/ceph/HealthMute.js
+++ b/www/manager6/ceph/HealthMute.js
@@ -14,12 +14,14 @@ Ext.define('PVE.ceph.HealthMuteInputPanel', {
             name: 'ttl',
             fieldLabel: gettext('Duration'),
             editable: true,
-            value: '',
+            value: '__default__',
             // without this an empty field is submitted as a request to delete the property,
             // which this endpoint does not accept
             deleteEmpty: false,
             comboItems: [
-                ['', gettext('No expiry')],
+                // KVComboBox cannot round-trip an empty string as a key, so use the
+                // toolkit's '__default__' sentinel, which it already drops on submit
+                ['__default__', gettext('No expiry')],
                 ['1h', gettext('1 hour')],
                 ['1d', gettext('1 day')],
                 ['1w', gettext('1 week')],
-- 
2.47.3