18927 notifications(mail): handle undefined vars

Mail notifications failed when the following variables were undefined:

  - `PREVIOUSHOSTHARDSTATE`
  - `PREVIOUSSERVICEHARDSTATE`

These variables now default to `UNKNOWN` when undefined.

Closes: #857
JIRA-Ref: SUP-26054
Co-authored-by: Logan Connolly <logan.connolly@checkmk.com>
Change-Id: I0809202931f353058ae64415d7bacfc0a792f251

Author: zerwes

.werks/18927.md

@@ -0,0 +1,21 @@
+[//]: # (werk v2)
+# Notifications: handle undefined mail variables
+
+key        | value
+---------- | ---
+date       | 2025-10-21T08:52:12+00:00
+version    | 2.5.0b1
+class      | fix
+edition    | cre
+component  | notifications
+level      | 1
+compatible | yes
+
+Mail notifications failed when the following variables were undefined:
+
+  - `PREVIOUSHOSTHARDSTATE`
+  - `PREVIOUSSERVICEHARDSTATE`
+
+These variables now default to `UNKNOWN` when undefined.
+
+No action is required from users to benefit from this improvement.

notifications/templates/mail/bulk.html.jinja

@@ -29,13 +29,13 @@
                         <td style="padding: 0; vertical-align: middle;">
                             <div class="mobile_event_marker_bulk"
                                  style="{{ macros.event_marker_bulk_style() }};
-                                        {% if service_notification %} {{ state_mapping[entry.PREVIOUSSERVICEHARDSTATE] }} {% else %} {{ state_mapping[entry.PREVIOUSHOSTHARDSTATE] }} {% endif %};
+                                        {% if service_notification %} {{ state_mapping[(entry.PREVIOUSSERVICEHARDSTATE|default("UNKNOWN") )] }} {% else %} {{ state_mapping[(entry.PREVIOUSHOSTHARDSTATE|default("UNKNOWN") )] }} {% endif %};
                                         display: inline-block;
                                         /* Inline block to respect width */">
                                 {% if service_notification %}
-                                    {{ entry.PREVIOUSSERVICEHARDSTATE[:4] }}
+                                    {{ (entry.PREVIOUSSERVICEHARDSTATE|default("UNKNOWN") )[:4] }}
                                 {% else %}
-                                    {{ entry.PREVIOUSHOSTHARDSTATE[:4] }}
+                                    {{ (entry.PREVIOUSHOSTHARDSTATE|default("UNKNOWN") )[:4] }}
                                 {% endif %}
                             </div>
                         </td>

notifications/templates/mail/summary.html.jinja

@@ -33,13 +33,13 @@
                             <tr>
                                 <td style=" line-height: 45px; padding: 0; ">
                                     <div style="{{ macros.event_marker_style() }};
-                                                {% if service_notification %} {{ state_mapping[data.PREVIOUSSERVICEHARDSTATE] }} {% else %} {{ state_mapping[data.PREVIOUSHOSTHARDSTATE] }} {% endif %};
+                                                {% if service_notification %} {{ state_mapping[(data.PREVIOUSSERVICEHARDSTATE|default("UNKNOWN") )] }} {% else %} {{ state_mapping[(data.PREVIOUSHOSTHARDSTATE|default("UNKNOWN") )] }} {% endif %};
                                                 display: inline-block;
                                                 /* Inline block to respect width */">
                                         {% if service_notification %}
-                                            {{ data.PREVIOUSSERVICEHARDSTATE[:4] }}
+                                            {{ (data.PREVIOUSSERVICEHARDSTATE|default("UNKNOWN") )[:4] }}
                                         {% else %}
-                                            {{ data.PREVIOUSHOSTHARDSHORTSTATE[:4] }}
+                                            {{ (data.PREVIOUSHOSTHARDSHORTSTATE|default("UNKNOWN") )[:4] }}
                                         {% endif %}
                                     </div>
                                 </td>