From cc2c345a362ae8e70e7f4df3bf7072df745bec8e Mon Sep 17 00:00:00 2001
From: Dragomir Penev <dragomir.penev@canonical.com>
Date: Fri, 10 Oct 2025 17:39:13 +0300
Subject: [PATCH] Check juju version before removing revision

---
 src/charm.py             |  7 +++++++
 tests/unit/test_charm.py | 32 ++++++++++++++++++++++----------
 2 files changed, 29 insertions(+), 10 deletions(-)

diff --git a/src/charm.py b/src/charm.py
index abf20da132..a252973d5e 100755
--- a/src/charm.py
+++ b/src/charm.py
@@ -42,6 +42,7 @@
     EventBase,
     HookEvent,
     InstallEvent,
+    JujuVersion,
     LeaderElectedEvent,
     MaintenanceStatus,
     ModelError,
@@ -666,6 +667,12 @@ def primary_endpoint(self) -> str | None:
             return primary_endpoint
 
     def _on_secret_remove(self, event: SecretRemoveEvent) -> None:
+        if self.model.juju_version < JujuVersion("3.6.11"):
+            logger.warning(
+                "Skipping secret revision removal due to https://github.com/juju/juju/issues/20782"
+            )
+            return
+
         # A secret removal (entire removal, not just a revision removal) causes
         # https://github.com/juju/juju/issues/20794. This check is to avoid the
         # errors that would happen if we tried to remove the revision in that case
diff --git a/tests/unit/test_charm.py b/tests/unit/test_charm.py
index ed0f3e2b83..5be6ef077a 100644
--- a/tests/unit/test_charm.py
+++ b/tests/unit/test_charm.py
@@ -15,7 +15,7 @@
 import pytest
 import tomli
 from charms.operator_libs_linux.v2 import snap
-from ops import RelationEvent, Unit
+from ops import JujuVersion, RelationEvent, Unit
 from ops.framework import EventBase
 from ops.model import (
     ActiveStatus,
@@ -2764,12 +2764,24 @@ def test_relations_user_databases_map(harness):
 
 
 def test_on_secret_remove(harness):
-    event = Mock()
-    harness.charm._on_secret_remove(event)
-    event.remove_revision.assert_called_once_with()
-    event.reset_mock()
-
-    # No secret
-    event.secret.label = None
-    harness.charm._on_secret_remove(event)
-    assert not event.remove_revision.called
+    with (
+        patch("ops.model.Model.juju_version", new_callable=PropertyMock) as _juju_version,
+    ):
+        event = Mock()
+
+        # New juju
+        _juju_version.return_value = JujuVersion("3.6.11")
+        harness.charm._on_secret_remove(event)
+        event.remove_revision.assert_called_once_with()
+        event.reset_mock()
+
+        # Old juju
+        _juju_version.return_value = JujuVersion("3.6.9")
+        harness.charm._on_secret_remove(event)
+        assert not event.remove_revision.called
+        event.reset_mock()
+
+        # No secret
+        event.secret.label = None
+        harness.charm._on_secret_remove(event)
+        assert not event.remove_revision.called