From 8364920acb272e2df5c6e261ca67622f3d6d1874 Mon Sep 17 00:00:00 2001
From: Sydney Runkle <54324534+sydney-runkle@users.noreply.github.com>
Date: Fri, 2 Feb 2024 13:19:03 -0600
Subject: [PATCH] Reverting problematic fix from 2.6 release, fixing schema
 building bug (#8718)

---
 pydantic/_internal/_generate_schema.py |  2 --
 tests/test_discriminated_union.py      |  1 +
 tests/test_json_schema.py              | 28 ++++++++++++++++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/pydantic/_internal/_generate_schema.py b/pydantic/_internal/_generate_schema.py
index fef419ac82..f6e80244dd 100644
--- a/pydantic/_internal/_generate_schema.py
+++ b/pydantic/_internal/_generate_schema.py
@@ -438,8 +438,6 @@ def clean_schema(self, schema: CoreSchema) -> CoreSchema:
         if collect_invalid_schemas(schema):
             raise self.CollectedInvalid()
         schema = validate_core_schema(schema)
-        if 'definitions' in schema:
-            schema['definitions'] = list(reversed(schema['definitions']))
         return schema
 
     def collect_definitions(self, schema: CoreSchema) -> CoreSchema:
diff --git a/tests/test_discriminated_union.py b/tests/test_discriminated_union.py
index fb12e2d661..0e3a0eeadb 100644
--- a/tests/test_discriminated_union.py
+++ b/tests/test_discriminated_union.py
@@ -1700,6 +1700,7 @@ class DiscriminatedModel(BaseModel):
         assert exc_info.code == 'callable-discriminator-no-tag'
 
 
+@pytest.mark.xfail(reason='Issue not yet fixed, see: https://github.com/pydantic/pydantic/issues/8271.')
 def test_presence_of_discriminator_when_generating_type_adaptor_json_schema_definitions() -> None:
     class ItemType(str, Enum):
         ITEM1 = 'item1'
diff --git a/tests/test_json_schema.py b/tests/test_json_schema.py
index 7a6488ad18..9a7671e52e 100644
--- a/tests/test_json_schema.py
+++ b/tests/test_json_schema.py
@@ -5879,3 +5879,31 @@ class Model(BaseModel):
         x: BaseModel
 
     assert 'description' not in Model.model_json_schema()['$defs']['BaseModel']
+
+
+def test_recursive_json_schema_build() -> None:
+    """
+    Schema build for this case is a bit complicated due to the recursive nature of the models.
+    This was reported as broken in https://github.com/pydantic/pydantic/issues/8689, which was
+    originally caused by the change made in https://github.com/pydantic/pydantic/pull/8583, which has
+    since been reverted.
+    """
+
+    class AllowedValues(str, Enum):
+        VAL1 = 'Val1'
+        VAL2 = 'Val2'
+
+    class ModelA(BaseModel):
+        modelA_1: AllowedValues = Field(..., max_length=60)
+
+    class ModelB(ModelA):
+        modelB_1: typing.List[ModelA]
+
+    class ModelC(BaseModel):
+        modelC_1: ModelB
+
+    class Model(BaseModel):
+        b: ModelB
+        c: ModelC
+
+    assert Model.model_json_schema()