Remove duplicated MAC addresses from multi MAC field

While adding new nodes, there is possibility to paste duplicated addresses in
multi MAC field. Check if this situation occurred, and remove duplication.

Closes-Bug: 1437212

Change-Id: I02436ce6db1b7ce42b98dbb18c1e96b4452db222

tuskar_ui/forms.py

@@ -97,15 +97,19 @@ class MultiMACField(forms.fields.Field):
 
     def clean(self, value):
         value = super(MultiMACField, self).clean(value)
-        try:
-            macs = []
-            for mac in SEPARATOR_RE.split(value):
-                if mac:
-                    macs.append(normalize_MAC(mac))
-            return ' '.join(macs)
-        except ValueError:
-            raise forms.ValidationError(
-                _(u'%r is not a valid MAC address.') % mac)
+
+        macs = []
+        for mac in SEPARATOR_RE.split(value):
+            if mac:
+                try:
+                    normalized_mac = normalize_MAC(mac)
+                except ValueError:
+                    raise forms.ValidationError(
+                        _(u'%r is not a valid MAC address.') % mac)
+                else:
+                    macs.append(normalized_mac)
+
+        return ' '.join(sorted(set(macs)))
 
 
 class NetworkField(forms.fields.Field):

tuskar_ui/test/test_forms.py

@@ -57,3 +57,12 @@ class MultiMACFieldTests(test.TestCase):
             "DE:AD:BE:EF:CA:FC DE:AD:BE:EF:CA:FD DE:AD:BE:EF:CA:FE "
             "DE:AD:BE:EF:CA:FF",
         )
+
+    def test_duplicated(self):
+        field = forms.MultiMACField(required=False)
+        cleaned = field.clean("DE:AD:BE:EF:CA:FC DE:AD:BE:EF:CA:FC")
+
+        self.assertEqual(
+            cleaned,
+            "DE:AD:BE:EF:CA:FC",
+        )