Fix #1518 Duplicate External Schema Components

modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/processors/ExternalRefProcessor.java

@@ -130,17 +130,8 @@ public String processRefToExternalSchema(String $ref, RefFormat refFormat) {
                 if (isAnExternalRefFormat(ref)) {
                     if (!ref.equals(RefFormat.URL)) {
                         String schemaFullRef = schema.get$ref();
-                        String parent = (file.contains("/")) ? file.substring(0, file.lastIndexOf('/')) : "";
-                        if (!parent.isEmpty() && !schemaFullRef.startsWith("/")) {
-                            if (schemaFullRef.contains("#/")) {
-                                String[] parts = schemaFullRef.split("#/");
-                                String schemaFullRefFilePart = parts[0];
-                                String schemaFullRefInternalRefPart = parts[1];
-                                schemaFullRef = Paths.get(parent, schemaFullRefFilePart).normalize() + "#/" + schemaFullRefInternalRefPart;
-                            } else {
-                                schemaFullRef = Paths.get(parent, schemaFullRef).normalize().toString();
-                            }
-                            schemaFullRef = FilenameUtils.separatorsToUnix(schemaFullRef);
+                        if (!schemaFullRef.startsWith("/")) {
+                            schemaFullRef = join(file, schemaFullRef);
                         }
                         schema.set$ref(processRefToExternalSchema(schemaFullRef, ref));
                     }

modules/swagger-parser-v3/src/test/java/io/swagger/v3/parser/test/OpenAPIV3ParserTest.java

@@ -35,6 +35,7 @@
 import static java.util.Arrays.asList;
 import static java.util.Collections.emptyList;
 import static org.testng.Assert.*;
+import static org.testng.Assert.assertEqualsNoOrder;
 
 
 public class OpenAPIV3ParserTest {
@@ -562,6 +563,16 @@ public void testIssue1518StackOverFlow() {
         }
     }
 
+    @Test
+    public void testIssue1518NestedExternalRefs() {
+        ParseOptions options = new ParseOptions();
+        options.setResolve(true);
+        SwaggerParseResult result = new OpenAPIV3Parser().readLocation("issue-1518-nested-ref/api.yaml", null, options);
+        OpenAPI openAPI = result.getOpenAPI();
+        Set<String> schemaKeys = openAPI.getComponents().getSchemas().keySet();
+        assertEqualsNoOrder(schemaKeys, Arrays.asList("SharedModel", "shared-model", "Wrapper", "Leaf"));
+    }
+
     @Test
     public void testCantReadDeepProperties() {
         OpenAPIV3Parser parser = new OpenAPIV3Parser();
@@ -3292,7 +3303,7 @@ public void testIssue1886() {
         OpenAPI openAPI = parseResult.getOpenAPI();
         assertEqualsNoOrder(
             openAPI.getComponents().getSchemas().keySet(),
-            Arrays.asList("ArrayPojo", "Enum1", "Enum1_1", "Enum2", "Enum3", "MapPojo", "SetPojo", "SimplePojo",
+            Arrays.asList("ArrayPojo", "Enum1", "Enum2", "Enum3", "MapPojo", "SetPojo", "SimplePojo",
                 "TransactionsPatchRequestBody", "additional-properties", "array-pojo", "locale-translation-item",
                 "map-pojo", "set-pojo", "simple-pojo", "translation-item")
         );

modules/swagger-parser-v3/src/test/resources/issue-1518-nested-ref/api.yaml

@@ -0,0 +1,19 @@
+openapi: 3.0.3
+info:
+  title: Duplicate Schema Repro
+  version: 1.0.0
+
+paths:
+  /shared-directly:
+    $ref: "./paths/direct.yaml"
+  /shared-nested:
+    $ref: "./paths/nested.yaml"
+
+components:
+  schemas:
+    SharedModel:
+      $ref: "./schemas/shared-model.yaml"
+    Wrapper:
+      $ref: "./schemas/wrapper.yaml"
+    Leaf:
+      $ref: "./schemas/leaf.yaml"

modules/swagger-parser-v3/src/test/resources/issue-1518-nested-ref/paths/direct.yaml

@@ -0,0 +1,10 @@
+get:
+  tags: [Repro]
+  operationId: getSharedDirectly
+  responses:
+    '200':
+      description: Path that returns the shared model directly.
+      content:
+        application/json:
+          schema:
+            $ref: "../api.yaml#/components/schemas/SharedModel"

modules/swagger-parser-v3/src/test/resources/issue-1518-nested-ref/paths/nested.yaml

@@ -0,0 +1,10 @@
+get:
+  tags: [Repro]
+  operationId: getSharedNested
+  responses:
+    '200':
+      description: Path that returns a wrapper whose items are the shared model.
+      content:
+        application/json:
+          schema:
+            $ref: "../api.yaml#/components/schemas/Wrapper"

modules/swagger-parser-v3/src/test/resources/issue-1518-nested-ref/schemas/leaf.yaml

@@ -0,0 +1,7 @@
+type: object
+required:
+  - id
+properties:
+  id:
+    type: string
+    format: uuid

modules/swagger-parser-v3/src/test/resources/issue-1518-nested-ref/schemas/shared-model.yaml

@@ -0,0 +1,9 @@
+type: object
+required:
+  - name
+  - leaf
+properties:
+  name:
+    type: string
+  leaf:
+    $ref: "../api.yaml#/components/schemas/Leaf"

modules/swagger-parser-v3/src/test/resources/issue-1518-nested-ref/schemas/wrapper.yaml

@@ -0,0 +1,8 @@
+type: object
+required:
+  - items
+properties:
+  items:
+    type: array
+    items:
+      $ref: "../api.yaml#/components/schemas/SharedModel"