From 87dfa2e92247bf02f41ad1c634d9d0c6755096d0 Mon Sep 17 00:00:00 2001
From: Daniel Fangl <daniel.fangl@localstack.cloud>
Date: Mon, 7 Feb 2022 20:07:15 +0100
Subject: [PATCH] correctly filter describe_managed_prefix_lists, add test for
 the behavior (#4837)

---
 moto/ec2/models.py          |  4 ++--
 tests/test_ec2/test_vpcs.py | 13 +++++++++++++
 2 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index 72eac17ae..da2359b9c 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -5566,8 +5566,8 @@ class ManagedPrefixListBackend(object):
 
         result = managed_prefix_lists
         if filters:
-            result = filter_resources(managed_prefix_lists, filters, attr_pairs)
-            result = describe_tag_filter(filters, managed_prefix_lists)
+            result = filter_resources(result, filters, attr_pairs)
+            result = describe_tag_filter(filters, result)
 
         for item in result.copy():
             if not item.delete_counter:
diff --git a/tests/test_ec2/test_vpcs.py b/tests/test_ec2/test_vpcs.py
index 3802d6b02..9938fc27e 100644
--- a/tests/test_ec2/test_vpcs.py
+++ b/tests/test_ec2/test_vpcs.py
@@ -1097,3 +1097,16 @@ def test_describe_vpcs_dryrun():
     ex.value.response["Error"]["Message"].should.equal(
         "An error occurred (DryRunOperation) when calling the DescribeVpcs operation: Request would have succeeded, but DryRun flag is set"
     )
+
+
+@mock_ec2
+def test_describe_prefix_lists():
+    client = boto3.client("ec2", region_name="us-east-1")
+    result_unfiltered = client.describe_prefix_lists()
+    assert len(result_unfiltered["PrefixLists"]) > 1
+    result_filtered = client.describe_prefix_lists(
+        Filters=[
+            {"Name": "prefix-list-name", "Values": ["com.amazonaws.us-east-1.s3"]},
+        ]
+    )
+    assert len(result_filtered["PrefixLists"]) == 1