20254 innovaphone(licenses): fix division by zero

Instead of crashing at runtime, the check should return an unknown
result when the total (denominator) is zero and still show the
used/total values in the result summary.

CMK-37821

Change-Id: Idcddd57aeb0477f7a9b3f88bf5a9d4ee8caf7ed3

Author: logan-connolly

.werks/20254.md

@@ -0,0 +1,21 @@
+[//]: # (werk v3)
+# innovaphone_licenses: fix division by zero error
+
+key        | value
+---------- | ---
+date       | 2026-08-07T04:53:19.239404+00:00
+version    | 3.0.0b1
+class      | fix
+edition    | community
+component  | checks
+level      | 1
+compatible | yes
+
+The _Licenses_ service on Innovaphone devices went UNKNOWN with a crash report
+when a device reported a total of 0 licenses (for example a misconfigured or
+not-yet-licensed system), since the utilization percentage was computed as a
+division by zero.
+
+A total of 0 no longer crashes the check; the service instead reports state
+UNKNOWN with "Utilization: n/a", while still showing the used and total
+counts.

cmk/legacy_checks/innovaphone_licenses.py

@@ -33,11 +33,14 @@ def check_innovaphone_licenses(_no_item, params, info):
     if not info:
         return None
     total, used = map(savefloat, info[0])
-    perc_used = (100.0 * used) / total
+    perc_used = (100.0 * used) / total if total else None
     warn, crit = params["levels"]
-    message = f"Used {used:.0f}/{total:.0f} Licences ({perc_used:.0f}%)"
+    utilization_message = f" ({perc_used:.0f}%)" if perc_used is not None else ""
+    message = f"Used {used:.0f}/{total:.0f} Licences{utilization_message}"
     levels = f"Warning/ Critical at ({warn}/{crit})"
     perf = [("licenses", used, None, None, 0, total)]
+    if perc_used is None:
+        return 3, message, perf
     if perc_used > crit:
         return 2, message + levels, perf
     if perc_used > warn:

tests/unit/cmk/legacy_checks/test_innovaphone_licenses.py

@@ -6,8 +6,6 @@
 # mypy: disable-error-code="misc"
 # mypy: disable-error-code="no-untyped-call"
 
-import pytest
-
 from cmk.legacy_checks.innovaphone_licenses import check_innovaphone_licenses
 
 
@@ -18,7 +16,6 @@ def test_check_innovaphone_licenses_metric_boundaries() -> None:
     assert perf == [("licenses", 50.0, None, None, 0, 100.0)]
 
 
-@pytest.mark.xfail(strict=True, raises=ZeroDivisionError, reason="a total of 0 crashes the check")
 def test_check_innovaphone_licenses_zero_total() -> None:
     assert check_innovaphone_licenses(None, {"levels": (90.0, 95.0)}, [["0", "0"]]) == (
         3,