[PATCH proxmox-backup] docs: lto barcode generator: allow digits in the label prefix or no prefix at all

[Jonas Theisen <j.theisen@proxmox.com>]

The prefix field only accepted letters, but the LTO Ultrium cartridge
label specification [0] allows both letters and digits in the six
character volume serial.
Since the generator just appends a zero-padded counter to the prefix,
digits need no special handling.

Allowing an empty prefix also enables users to just generate basic
incrementing number labels.
This was already possible by adding a config entry and then removing
the prefix in the edit window.

Dropping the end of line "$" for clarity since the maskRe property
is matched against single characters.

[0] https://www.ibm.com/support/pages/system/files/inline-files/19P0034_N99211B_LTOCARTRIDGELABELSPEC.pdf

Came up in: https://forum.proxmox.com/threads/187519/

Signed-off-by: Jonas Theisen <j.theisen@proxmox.com>
---
 docs/lto-barcode/prefix-field.js | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/docs/lto-barcode/prefix-field.js b/docs/lto-barcode/prefix-field.js
index e12f1bda2..208e9efb5 100644
--- a/docs/lto-barcode/prefix-field.js
+++ b/docs/lto-barcode/prefix-field.js
@@ -3,9 +3,8 @@ Ext.define('PrefixField', {
     alias: 'widget.prefixfield',
 
     maxLength: 6,
-    allowBlank: false,
 
-    maskRe: /([A-Za-z]+)$/,
+    maskRe: /[A-Za-z0-9]/,
 
     listeners: {
 	change: function(field) {
-- 
2.47.3