From 94772806b2ff158268924d2f431778dba12e8b74 Mon Sep 17 00:00:00 2001
From: mueller-ma <22525368+mueller-ma@users.noreply.github.com>
Date: Mon, 13 Jul 2026 15:00:22 +0200
Subject: [PATCH] Fix crash when editing rules with hyphenated predefined
 condition IDs

Predefined condition identifiers created in Checkmk 2.4 or earlier could
contain hyphens (e.g. 'cond_host_monitoring-01'). The new rule catalog
renderer passed these idents directly as SingleChoiceElement names, which
requires valid Python identifiers, causing a ValueError when opening or
editing any rule that referenced such a condition.

Fix by using SingleChoiceExtended / SingleChoiceElementExtended (internal
API) instead of the public SingleChoice / SingleChoiceElement for the
predefined conditions list. The Extended variants do not validate names as
Python identifiers.

Refs: https://forum.checkmk.com/t/unable-to-edit-rules-when-explicit-hostname-contains-hyphens/59918
---
 .werks/20201.md             | 21 +++++++++++++++++++++
 cmk/gui/watolib/rulesets.py |  4 ++--
 2 files changed, 23 insertions(+), 2 deletions(-)
 create mode 100644 .werks/20201.md

diff --git a/.werks/20201.md b/.werks/20201.md
new file mode 100644
index 00000000000..01df6cfa668
--- /dev/null
+++ b/.werks/20201.md
@@ -0,0 +1,21 @@
+[//]: # (werk v3)
+# Fix crash when editing rules with predefined conditions whose ID contains hyphens
+
+key        | value
+---------- | ---
+date       | 2026-07-13T00:00:00+00:00
+version    | 3.0.0b1
+class      | fix
+edition    | community
+component  | wato
+level      | 1
+compatible | yes
+
+Previously, opening or editing a rule that referenced a predefined condition whose unique ID
+contained a hyphen (e.g. `cond_host_monitoring-01`) caused a crash with the error:
+
+_ValueError: 'cond_host_monitoring-01' is not a valid, non-reserved Python identifier_
+
+This affected predefined conditions created in Checkmk 2.4 or earlier that used hyphens in
+their ID. The issue only appeared in the rule editor — the conditions themselves still matched
+correctly at runtime.
diff --git a/cmk/gui/watolib/rulesets.py b/cmk/gui/watolib/rulesets.py
index d935c56f908..8c170835544 100644
--- a/cmk/gui/watolib/rulesets.py
+++ b/cmk/gui/watolib/rulesets.py
@@ -2452,10 +2452,10 @@ def _create_rule_conditions_catalog_topic(
                             CascadingSingleChoiceElementAPI(
                                 name="predefined",
                                 title=Title("Predefined conditions"),
-                                parameter_form=SingleChoiceAPI(
+                                parameter_form=SingleChoiceExtendedAPI(
                                     title=Title("Predefined condition"),
                                     elements=[
-                                        SingleChoiceElementAPI(
+                                        SingleChoiceElementExtendedAPI(
                                             name=n, title=Title("%(title)s") % {"title": t}
                                         )
                                         for n, t in PredefinedConditionStore().choices()