From 33bd1bc09b99f5245aad388585402e8f8d9de882 Mon Sep 17 00:00:00 2001
From: Ankush Menat <ankush@frappe.io>
Date: Tue, 7 Jan 2025 11:55:02 +0530
Subject: [PATCH] fix: Flushall shouldn't attempt reading keys

---
 frappe/tests/test_client_cache.py | 30 ++++++++++++++++++++++++++++++
 frappe/utils/redis_wrapper.py     |  1 +
 2 files changed, 31 insertions(+)

diff --git a/frappe/tests/test_client_cache.py b/frappe/tests/test_client_cache.py
index 45369e4ff9..549d015d3c 100644
--- a/frappe/tests/test_client_cache.py
+++ b/frappe/tests/test_client_cache.py
@@ -44,6 +44,36 @@ class TestClientCache(IntegrationTestCase):
 		self.assertEqual(frappe.client_cache.statistics.misses, 1)
 		self.assertEqual(frappe.client_cache.statistics.hit_ratio, 0.5)
 
+	def test_delete_invalidates(self):
+		val = frappe.generate_hash()
+		frappe.client_cache.set_value(TEST_KEY, val)
+		self.assertEqual(frappe.client_cache.get_value(TEST_KEY), val)
+
+		val = frappe.generate_hash()
+		frappe.cache.delete_value(TEST_KEY)
+		# This is almost instant, but obviously not as fast as running the next instruction in
+		# current thread. So we wait.
+		time.sleep(0.1)
+
+		with self.assertRedisCallCounts(1, exact=True):
+			self.assertIsNone(frappe.client_cache.get_value(TEST_KEY))
+
+		# Flushall should have results
+		frappe.client_cache.set_value(TEST_KEY, val)
+		self.assertEqual(frappe.client_cache.get_value(TEST_KEY), val)
+		frappe.cache.flushall()
+		time.sleep(0.1)
+		with self.assertRedisCallCounts(1, exact=True):
+			self.assertIsNone(frappe.client_cache.get_value(TEST_KEY))
+
+		# frappe.clear_cache should have same results
+		frappe.client_cache.set_value(TEST_KEY, val)
+		self.assertEqual(frappe.client_cache.get_value(TEST_KEY), val)
+		frappe.clear_cache()
+		time.sleep(0.1)
+		with self.assertRedisCallCounts(1, exact=True):
+			self.assertIsNone(frappe.client_cache.get_value(TEST_KEY))
+
 	def test_client_local_cache_ttl(self):
 		c = ClientCache(ttl=1)
 		c.set_value(TEST_KEY, 42)
diff --git a/frappe/utils/redis_wrapper.py b/frappe/utils/redis_wrapper.py
index 3030c2c632..177d1885da 100644
--- a/frappe/utils/redis_wrapper.py
+++ b/frappe/utils/redis_wrapper.py
@@ -542,6 +542,7 @@ class ClientCache:
 		if message["data"] is None:
 			# Flushall
 			self.clear_cache()
+			return
 		with self.lock:
 			for key in message["data"]:
 				self.cache.pop(key, None)