From 28ed4b18d86f3890c4de879819a86fa8543899eb Mon Sep 17 00:00:00 2001
From: "jaipilot[bot]" <273169020+jaipilot[bot]@users.noreply.github.com>
Date: Sat, 22 Aug 2026 16:30:21 +0000
Subject: [PATCH] Lock OAS 3.1 type deserializer behavior and drop a dead null
 check

---
 .../io/swagger/v3/core/jackson/mixin/Schema31Mixin.java   | 2 +-
 .../core/deserialization/JsonSchemaTypeRoundTripTest.java | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/mixin/Schema31Mixin.java b/modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/mixin/Schema31Mixin.java
index 066151dd39..44f7315461 100644
--- a/modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/mixin/Schema31Mixin.java
+++ b/modules/swagger-core/src/main/java/io/swagger/v3/core/jackson/mixin/Schema31Mixin.java
@@ -100,7 +100,7 @@ public Set<String> deserialize(JsonParser p, DeserializationContext ctxt) throws
             Set<String> types = new LinkedHashSet<>();
             if (node.isArray()) {
                 node.forEach(n -> {
-                    if (n != null && !n.isNull()) {
+                    if (!n.isNull()) {
                         types.add(n.asText());
                     }
                 });
diff --git a/modules/swagger-core/src/test/java/io/swagger/v3/core/deserialization/JsonSchemaTypeRoundTripTest.java b/modules/swagger-core/src/test/java/io/swagger/v3/core/deserialization/JsonSchemaTypeRoundTripTest.java
index 4bc335b576..cf0965c881 100644
--- a/modules/swagger-core/src/test/java/io/swagger/v3/core/deserialization/JsonSchemaTypeRoundTripTest.java
+++ b/modules/swagger-core/src/test/java/io/swagger/v3/core/deserialization/JsonSchemaTypeRoundTripTest.java
@@ -48,6 +48,14 @@ public void multiTypeArrayRoundTripsOnJsonSchema() throws Exception {
         assertEquals(roundTripped.getTypes(), setOf("string", "null"));
     }
 
+    @Test
+    public void typeArrayWithLiteralJsonNullElementSkipsIt() throws Exception {
+        JsonSchema roundTripped = Json31.mapper().readValue("{\"type\":[\"string\",null]}", JsonSchema.class);
+
+        assertNotNull(roundTripped);
+        assertEquals(roundTripped.getTypes(), setOf("string"));
+    }
+
     @Test
     public void convertValuePreservesSingleType() {
         JsonSchema original = new JsonSchema();